DEPARTMENT OF THE INTERIOR

ALBEET B. FALL, Secretary

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, Director 

Bulletin 740

MICA DEPOSITS OF THE UNITED STATES

DOUGLAS B. STERRETT

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1923

1-
-V-rM 

!" i i<

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CONTENTS. 

 

1'ngo.

Introduction____________________________________ 1

Bibliography_____________________________________ 1

Geology ______ _____________ _ 4

General features________________________________ 4

Pegmatite______________________________________ 5

Occurrence _______________________________ 5

Genesis_________________________________ 8

Mineralogy ______________ _______ ______________ 11

Composition__________________________________ 11

Crystallography _____________________________ __ 11

Physical properties_____________________________ 14

Mica mining__________________ ____ _ ________ . 17

History___________________.___________________ 19

Methods_____________________:_____________ 20

Preparation of mica for the market____________________ 21

Uses_____________________________________ 28

Grades____________________________________ 2G

Production and imports____________________..______ 26

Description of mines______________________________ 28

Alabama____.......___...._.._______________________ 2S

General features____________________________ 28

Coosa County _________ ____________________ 30

Randolph County_____________________________ 30

Tallapoosa County___________________________ 43

Arizona________________________.,___________ 40

California___________________________________ 47

General features ..__________________________ 47

Ventura County__________^__________________ 48

: Colorado___________________________________ 49

General features_____________________________ 49

Chaffee County__i___________________________ 49

Fremont County_____________________________ 49

Micanite region. __________________________ 51

Royal Gorge region_________________________ 55

Texas Creek region _________________ _ _ 56

Jefferson County_____________________________ 57

Larimer County______________________________ 59

Mesa County_____________ ____________________ 61

Connecticut__________________________________ 62

General features_______-_ _______ ______ 62

Litchfield County____________________________ 63

Middlesex County__________________________ 65

Hartford County_______._________. _______ __ 69

JsTew Haven County__________________________ 70

Georgia ____________________________________ 70 

General features ______ ___________________ 70

Carroll County_____________________________ 71
IV CONTENTS.

Description of mines Continued.

Georgia Continued. Page.

Cherokee County_____________________________ 72

Elbert County _____________________________ 75

Hall County_______________________________ 76

Hart County. ___ __ __________________ 77,

Lumpkin and Union counties_____________________ 78

Paulding County_____________________________ S3

Pickens County _______-______________________ 83

Rabun County-_____________________________ 85

Talbot County_____________________________ 86

Troup County ________________________________ 86

Upson County _______________________________ 86

Idaho______________________________________ 86

Latah County___ _ __-__________________ 86

Washington County ___________________________ 93

Maine________________________________________ 94

General features_____________________________ 94

Androscoggin County_ _______________________ 94

Oxford County______________________________ 95

Sagadahoc County __________ __________________ 100

Maryland______________________________________ 101

General features __ ___ _ - ______ 101

Baltimore County____________________________ 102

Howard County_____________________________ 102

Montgomery County___________________________ 104

Massachusetts _________________________________ 105

Montana ____________________________________ 105

Nevada __________..__ __ _ _ 105

New Hampshire ________________________________ 100

General features____________________________ ] 00

Cheshire County ____________________ _____....____ 107

Grafton County______________________________ 118

Sullivan County_____ ______________________ 151

Strafford County,...___ _________________________ 156

New Jersey________________ ____ _ ____ 158

New Mexico ____________ __ ___ _ _ 158

General features_____ _____ _ ____________ 158

Mora County _ _____ 158

Rio Arriba County ___ ___ _ _ _ L59

San Miguel County___ _ _ _ 164

New York _ 165

General features. 165

St. Lawrence County______ ________________ __ 165

Saratoga County______________ _______--. 166

Westchester County__ _ _ 166

North Carolina_________ 167

General features___ _ 167

Occurrence of deposits- 170

Minerals associated with pegmatite '__ 170

Production_______ 171

Ashe County____ - ^- 172

Avery County 177

Buncombe County____ 184
CONTENTS. V

Description of mines Continued.

North Carolina Continued. 1'agc.

Burke County________________________________ 188

Catawba County_____________________________ 188

Cleveland County_________________________ 189

Gaston County_________ ______________ _ _ 193

Haywood County ___________________________.. 194

Jackson County__________________________-_ 197

Lincoln County____________________________.._ 220

McDowell County______________________..____ 224

Macon County_______________________________. 224

Mitchell County_____________________________ 245

Rutherford County____________________._____ 261

Stokes County_____________________________ 263

Transylvania County____________________ __ 265

Wake County_______________________.______ 268

Warren County_____________________________ 268

Watauga County____________________________ 269

Wilkes County______________________________ 271

Yadkin County_________________________...____ 271

Yancey County______________________________ 273

Pennsylvaniu ___________ _________________ 279

General features____________________________ 279

Delaware County___ __ ___ ____ 279

South Carolina__________________________________ 281

General features__________ ____________________ 281

Anderson County_____________________________ 282

Greenville County____________________________ 286

Oconee County______________________________ 288

South Dakota_________________________________ 289

General features________ _________________ 289

Geology of the Black Hills_______________________ 289

Custer County________________________________ 292

Texas________________________________________ 302

General features______________________________ 302

Culberson County_____________________________ 303

Mason County_______________________________ 30C

Utah_________________________________________ 300

Vermont________________________________.._____ 307

Virginia_____-________________________________________________ 307

General features______________________________ 307

Amelia County-^______________________________ 308

Bedford County___________________________..__..__ 318

Franklin County___________ - ___________________..____. 319

Goochland County______________________________ 320

Hanover County_______________________ ___ 321

Henry County__________:_____________________ 322

Henry and Pittsylvania counties________________..___ 327

Pittsylvania County_______________________.._____ 320

Washington ______._________________________ ___ . 830

Wyoming________'________________________.._____ 330

General features_______________________ .'-.... _^._ 330

Albany County______________________..___.________ 330

Laramie County_____ ________.._____________ 331

.Index _________________._..__..________.._.._____ 335
.ILLUSTRATIONS.

Tage. 

PLATE I. Specimen of "graphic granite," a graphic intergrowth of microcline and quartz__________________________ 18 

" i IT. A, Mica "capping"; B, Solid mica, consisting of aggregates of

"wedge" and A mica_______________________ 18

III. A, Cleavage sheet from mica crystal, showing percussion 

figures; B, Specimens of " ruled mica," some " ruled" into 

" ribbons " ______________________________ 18

IV. A, Fragment of crystal of mica, showing A structure; B, Mica

crystal showing "fishbone" or "herring-bone" structure__ 18

V. Mica crystals, showing "wedge" and "fishbone" structure__ 18

VI. Cleavage plates of mica showing various kinds of structure____ 18

VII. A, B, Mica " specked " with magnetite___.___________ 18 

VIII. A, Sheet of mica containing inclusions resembling ancient 

I) hieroglyphics; B, Sheet of mica inclosing two flattened 

garnet crystals; C, Sheet of biotite from Mitchell County, 

N. C., inclosing a rhombic crystal of muscovite, both having 

the same cleavage planes______-______________ 19

IX. A, Mass of solid mica exposed in open cut at Grady mica mine, 

Mesa County, Colo.; B, View northward toward open cut in 

pegmatite inclosed in mica gneiss, Texas Mica Co., Culberson 

! County, Tex_____ _______ 62

X. Block of solid mica blasted loose from pegmatite at George

Roebling mica mine, Litchfleld County, Conn_____ 63

XI. Map showing location of mica deposits of Georgia______- 72

XII. Map showing location of some of the mica mines and prospects

in New Hampshire___________ _ 108

XIII. A, View northeastward across the quarry of the Franklin 

Playter mica-beryl mine, Sullivan County, N. H., showing the 

pinching of pegmatite between mica gneiss walls; B, View 

southwestward over the open cut of the Granite State Mica 

Co.'s mine, Cheshire County, N. H______ _ 108

XIV. A, View N. 15° W. across the main open cut of the Rhoda mica 

mine, Cheshire County, N. H.; B, Mica crystals in a face of 

pegmatite in the. deep stope under open cut shown in A______ 108

XV. A, View southwestward across open cut of the French mica mine, 

Cheshire County, N. H.; B, View north of east in the open cut 

of the Kilton mica mine, Crafton County, N. H.______ 108

XVI. A, View from middle of north side of open cut of Keene Mica 

Products Co.'s mica mine, Cheshire County, N. H.; B, Enrichment of mica in pegmatite along the west side of the horse of 

mica gneiss shown in A_________________________ 108

XVII. A, Fork in the pegmatite at General Electric Co.'s mica mine, 

near West Rumney, N. H.; B, View northeastward down into 

the stopes of the Palermo mica mine, near North Groton, 

N. H._____________________________1_ 108

VI
iLLUSTKATIONS. VII

PLATE. Page.

XVIII. A, Contact between pegmatite and overlying gneiss at Sanborn 

mica mine, Grafton County, N. H.; B, View southwestward 

across the open cut of the Belden or Standard mica mine, 

Grafton County, N. H________________________ 109

XIX. Map showing location of mica mines and prospects in western

North Carolina _____________________________ 170

XX. A, View in stope of North Hardin mica mine, 'Ashe County, 

N. C.; B, Mica-trimming shop of Walnut Knob mica mine, Ashe 

County, N. C_______________________________ 170

XXI. A, View northward toward Meadows mica mine, Avery County, 

N. C.; B, Pegmatite showing fine-grained contact near wall, at 

McKinney or Powdermill Creek mica mine, Avery County, 

N. C__________________________________ 171

XXII. View eastward toward workings of Carolina Mineral Co.'s micafeldspar mine, near Penland, Mitchell County, N. C.____ 260

XXIII. A, View westward toward workings of Carolina Mineral Co.'s 

mica-feldspar mine, near Penland, Mitchell County, N. C.; 

B, View northwestward toward Harris workings of Harris 

Clay Co.'s kaolin mine, near Penland, Mitchell County, N. C__ 260

XXIV. A, View eastward across deep open stope of the Wiseman mica 

mine, Carolina Mineral Co., on Beaver Creek, Mitchell County, 

N. C.; B, View northward toward workings of Willimon mica 

mine, Greenville County, S. C_________________ 260 

. XXV. A, View southward from Harney Peak, Black Hills, S. Dak., 

showing outcrops of pegmatitic granite; If, View northward 

toward New York mica mine, near Custer, S. Dak_____ 261 

XXVI. A, View northward along pegmatitic outcrop at New York mica 

mine, ciiear Custer, S. Dak.; B, Crystals of mica in pegmatite and blasted loose on 200-foot level of New York rnica 

mine, near Custer, S. Dak __ _____.__ _ 300 

XXVII. A, View northward toward engine and shaft 1 ouse of White 

Spar mica mine, near Custer, S. Dak.; B, End1 of intrusion 

of small dike of pegmatite at Crown mica mine, near Custer, 

S. Dak _________________________________ 300 

XXVIII. A, Contact of pegmatite and gneiss in northeast face of open 

cut at Firestone mica mine, near Custer, S. Dak.; B, Large 

crystals of black tourmaline exposed in small cut along wall 

of pegmatite at Philip Geering's mica prospect, near Custer, 

S. Dak _________________________________ 300 

XXIX. A, Surface equipment of Champion No. 2 mica .mine, Amelia 

County, Va.; B, Interior of mica-trimming house of Ridgeway 

Mica Co., Ridgeway, Va______________________ 301 

FIGUBE 1. Diagram showing position of rays of the percussion and pressure figures in a crystal of muscovite mica________,_ 12

2. Plan of mine No. 1 of Great Southern Mica Co., 3| miles

S. 25° E. of Pinetuckey, Randolph County, Ala_______ 31

3. Plan of mine No. 5 of Great Southern Mica Co., 2 miles N.

35° E. of Pinetuckey, Randolph County, Ala_________ 32

4. Plan of M. & G. Co.'s mica mine, 2$ miles northeast of Pyriton, Clay County, Ala__ ____________________ 40

5. Plan of T. H. Glower's mica prospect, 2$ miles north of Opelika, Lee County, Ala______________________ 45
VIII ILLUSTRATIONS.

Page.

FIGURE 6. Plan and cross section of Climax mica claim or working No. 8 

of the United States Mica Co., 25 miles northwest of Canon 

City* Frernont County, Colo____________________ 53

7. Plan and cross section of South mine of United States Mica 

Co., 25 miles northwest of Canon City, Fremont County, 

Colo _________________________________ 54

8. Plan of workings of Buckhorn Mica Mining & Milling Co., 17

miles S. 75° W. of Fort Collins, Larimer County, Colo___ 59

9. Outcrop of irregular streak of mica between quartz and feldspar in S. A. Grady's claim, Mesa County, Colo_______ 62

10. Plan of George Roebling mica, feldspar, and beryl mine near

Merryall, Litchfield County, Conn., showing part of geology- 63

11. Plan of Strickland feldspar, mica, and gem quarry, 2$ miles

northeast of Portland, Conn., showing geology________ 66

12. Plan of Gillette or Haddarn Neck feldspar and gem quarry, 

1 mile N. 22° E. of Hadclam, Conn., on east bank of Connecticut River, showing geology____________:____ 68

13. Plan of W. J. Cook mine, 8 miles S. 80° E. of Canton, Cherokee County, Ga__________________________ 74

14. Sketch map of workings at Hope mica mine, near Gainesville, Hall County, Ga_______________________ 76

15. Sketch map of parts of Lumpkin and Union counties, Ga.,

showing location of principal mica mines and prospects___ 79

16. Sketch map showing position of mica deposits in Latah

County, Idaho ___________________________ 88

17. Sketch map showing position of workings of Muscovite mica

claim, Latah County, Idaho__________________ 90

18. Relations of pegmatite and wall rock at Hibbs feldspar and

mica mine, Hebron, Maine__________________ 96

19. Diagram showing geologic structure at Mount Mica tourmaline mine, Paris, Maine____________________ 97

20. Plan of the Davis and Rhoda mines, Cheshire County, N. H.,

showing part of geology__________________ _ 110

21. Plan of Island mica mine, 2 miles N. 20° W. of Gilsum,

Cheshire County, N. H., showing geology___ __ __ 112

22. Plan of French mica mine of American Insulator & Mica Co., 

If miles northwest of Gilsum, Cheshire County, N. H., 

showing geology_______:__________ _ 113

23. Plan and cross section of Keene Mica Products Co.'s mine,

Cheshire County, N. H., showing geology___________ 114

24. Plan of Jehial White mica mine, 1 mile south of Gilsum.

Cheshire County, N. H., showing part of geology_ __ 116

25. Plan of Brooks mica prospect, near East Sullivan, Cheshire

County, N. H__________________________ 118

26. Plan of General Electric Co.'s mica mine near Swainsboro,

Grafton County, N. H______________________ 119

27. Plan of Wheat mica mine, West Rumney, Grafton County,

N. H., showing geology_____________ 121

28. Plan of Valencia mica mine, 2£ miles N. 75° E. of North

Groton, N. H., showing geology_________________ _ 124

29. Plan of Fletcher mica mine, 2£ miles east of North Groton,

N. H., showing geology________ 126
ILLUSTRATIONS. 1X1

PageFIGUEE 30. Plan of Union mica .mine, 1 mile N. 10° E. of North Grotou,

N. H., showing geology _ _ 128-

31. Plan of Palermo mica mine, 1$ miles southwest of North

Groton, N. H., showing geology___ __ __ 131

32. Plan and cross section of Keyes mica mine, 4f miles northeast of Canaan, Grafton County, N. H., showing part of 

geology 134-

33. Plan and cross section of Sanboru mica mine, 3£ miles N. 70°

E. of Canaan, Grafton County, N. H., showing geology 135

34. Plan of Belden or Standard mica mine, 3 miles N. 75° E. of

Canaan, Grafton County, N. H______________ _ 136

35. Sketch showing relative position of upper, lower, and old 

workings and dumps of Ruggles mica mine on the south end 

of Isinglass Mountain, Grafton County, Nv H. 140>

36. Plan and cross section of upper workings of Ruggles mica

mine, Grafton County, N. H__________..__ - . 141

37. Plan and cross section of lower workings of Ruggles mica

mine, Grafton County, N. H__________________ 142'

38. Plan of .Kilton mica mine, near Grafton Center, Grafton

County, N. H., showing geology_______________ 143

39. Plan of Alger mica mine, near Grafton Center, Grafton

County, N. H., showing geology______________ 145>

40. Plan of De Mott mica mine, on Prescott Hill, Grafton County,

N. H., showing geology_____________________ 146

41. Cross section of east half of quarry at Reynolds beryl mine, 

2i miles S. 25° W. of Grafton, N. H., showing relation of pegmatite to gneiss__________________________ 152'

42. Plan of Prospect of Columbian Gem Mining Co., on Springfield

Mountain, Sullivan County, N. H________________ 153

43. Plan of Foss mica mine, Strafford County, N. H________ 157"

44. Map showing areas in North Carolina in which mica has been

mined____________________________,___ 168-

45. Plan of North Hardin mica mine, Ashe County, N. C_____ 174

46. Walnut Knob mica mine, Ashe County, N. C__________ 177"

47. Plan of Meadows mica mine, near Plumtree, Avery County,

N. C__________._______________.____________ 178

48. Plan of Charlies Ridge mica mine, near Spear, Avery County,

N. C___________________________________ 182-

49. Plan of New Balsam Gap mica mine, Buncombe County, N. C 185

50. Plan of Connally mine, Buncombe County, N. C_______ 18$

51. Plan of Piney Mountain mica mine, Jackson County, N. C_ 198

52. Section in plane of " vein " at Painter mica mine, Jackson

County, N. C_____________________________ 199'

53. Section of pegmatite at Adams mica mine, 1$ miles southeast of Webster, Jackson County, N. C___________ 202

54. Plan of Adams mica mine near Webster, Jackson County.

N. C., showing geology ____________________ 202-

55. Uneven contact of pegmatite and mica gneiss at Gregory mica

mine, Jackson County, N. C___________________ 204

56. Plan of Presley mica mine, Jackson County, N. C_______ 20f»

57. Plan of John Long mica mine No. 1, Jackson County, N. C.,

showing geology___________________;______ i^on:
Z ILLUSTRATIONS.

Page. 

FIGURE. 58. Plan of John Long mica mine No. 2,. Jackson County, N. C_ 207

59. Plan of Wayehutta kaolin and mica mine, Jackson County,

N. C _________________________________ 208

60. Plan of Roda kaolin and mica mine, Jackson County, N. C_' 214

61. Section showing fork of pegmatite in Rice mica and beryl

mine, Jackson County, N. C_________________ 215

62. Section of pegmatite at mica prospect, near Chink Knob,

'Jackson County, N. C_______________________ 217

63. Plan of Jim Wood mica mine, Jackson County, N. C_____ 217

64. Plan of Hall and Welch mica mines, Macon County, N. C__ 234

65. Plan of lotla Bridge kaolin and mica mine, Macon County,

N. C_________________________________ 235

66. Plan of'Winecoff mica mine, Macon County, N. C_______ 236

67. Plan of Burningtown or Poll Miller mica mine, Macon County,

N. C________________________________ 239

68. Cross section of pegmatite 2£ feet thick at Wayah Bald mica

mine, Macon County, N. C___________________ 240

69. Cross section of pegmatite 8 to 10 feet thick at Turkey's Nest

mica mine, on Wayah Bald Mountain, Macon County, N. C. 241

70. Cross section of pegmatite at Thorn Mountain mica mine No.

2 Macon County, N. C________________________ 242

71. Plan of Flat Rock mica mine, 1 mile northeast of Penlaud,

Mitchell County, N. C______________________ 251

72. Sketch showing position of workings and part of geology at 

feldspar-mica mine of Carolina Mineral Co., Penland, Mitchell County, N. C_______________________- 252

73. Plan of W. W. Wiseman mica mine, on Beaver Creek, Mitchell

County, N. C., showing geology__________ _ 259

74. Section in plane of pegmatite at Knob mica mine, Mitchell

County, N. C___________________________ 260

75. Plan of Isinglass Hill mica mine, Rutherford County, N. C.,

showing probable shape of the pegmatite _ _ 262

76. Ideal cross section at Hole mica mine, Stokes County, N. C. 264

77. Plan of Hauser mica mine, 6 miles east of Yadkinville,

Yadkin County, N. C_______________________ 272

78. Plan of Poll Hill mica mine, Yancey County, N. C_____- 274

79. Vertical cross section of pegmatite at Hensley mica mine,

Yancey County, N. C_______________________ 276

80. Plan of Cattail Branch mica mine, Yancey County, N. C 277

81. Plan of workings at Gaillard mica mine, 6 miles S. 75° W.

of Starr, Anderson County, S. C________________ 282

82. Outcrops at Fretwell mica prospects, \\ miles west of Barnes,

Anderson County, S. C____________________ 284

83. Plan of Willimon mica mine, 9 miles 'southeast of Greenville,

Greenville County, S. C__________________ 287

84. Generalized cross section of No. 1 or New York mica mine,

near Custer, S. Dak________________________ 294

85. Plan of No. 2 or White Star mica mine, near Custer, S. Dak__ 296

86. Crown mica mine near Custer, S. Dak____________ 298

87. Plan and cross section of Great Northern or Old Mike mica

mine, near Custer, S. Dak_______ _______ 299
ILLUSTRATIONS. XI

Page.

88. Sketch of Texas Mica Co.'s claims, 15 miles southwest of Van 

Horn, Culberson County, Tex., showing topography and 

geology ,.__________________ 305

89. Champion mine No. 1, of Jefferson mines, 2$ miles N. 20° E.

of Amelia, Amelia County, Va__________________. 31.1

90. Plan of workings at Champion mine No. 2, of Jefferson mica

mines, 2£ miles N. 20° E. of Amelia, Amelia County, Va__ 312

91. Sketch showing position of workings at mines of Virginia 

Mica Producing & Manufacturing Co., 3 miles N. 17° E. of 

Amelia, Amelia County, Va__________._______ 313

92. Sketch showing position of workings at Pinchbeck micafeldspar mines, Amelia, Amelia County, Va_________ 314

93. Mines of the International Mica Co., 2 miles N. 20° E. of

Amelia, Amelia County, Va__________________ 316

94. Plan of the mica mine of the American Asbestos Co., 9 miles

east-southeast of Bedford City, Bedford County, Va___ 319

95. Plan of Ridgeway Mica Co.'s mine, Ridgeway, Henry County,

Va________ ________________________ 324

96. Plan of Harston mica mine, 3i miles north of Axton, Henry

County, Va_____________________________ 328.

MICA DEPOSITS OF THE UNITED STATES.

By DOUGLAS B. STEREETT.

INTRODUCTION.

Material for this report has Seen gathered at-different times during the last 20 years, chiefly under the direction of the United States 

Geological Survey, but a large part of the work in North Carolina 

was done under the auspices of the North Carolina Geological and 

Economic Survey. Much of the earlier field work was done in connection with other geologic investigations; not as a consecutive study 

of the mica deposits. This is unfortunate, for it has not been possible 

to revisit some of the mines examined, which have since been considerably developed.

Several preliminary reports on the occurrence of mica in certain 

States have been published by the United States Geological Survey, 

and a few descriptions of mines and general information on mica 

have appeared in the annual reports on the Mineral Kesources of the 

United States. Parts of these reports have been reprinted in this 

volume, with revision where necessary, and general information has 

also been freely abstracted from them. The writer has tried to give 

proper credit to other authors for their work. Thus the reports of 

E. S. Bastin and S. H. Ball are used in the description of mica deposits of Maine- and Wyoming, respectively, for the writer has done 

practically no field work on mica in those States. Bastin's report on 

feldspar has also furnished sources of information regarding mica 

in Connecticut, New York, and Pennsylvania. Only a few mica deposits in Georgia have been visited by the writer, and the rest of the 

information on deposits in Georgia has been abstracted from a State 

report on the feldspar and mica deposits of Georgia by S. L. Galpin. 

These reports and others are entered in the following bibliography.

BIBLIOGRAPHY.

ATKINSON, A. S., Mica mining: Eng. and Min. Jour., May 8, 1909, p. 941. 

BALL, S. H., Mica in the Hnrtville uplift, Wyo.: U. S. Geol. Survey Bull. 315,

pp. 423-425, 1906. 

BASTIN. E. S., Feldspar and quartz deposits of Maine and southeastern New

York: U. S. Geol. Survey Bull. 315, pp. 383-399, 1906.

1
2 MICA DEPOSITS OF THE UNITED STATES.

BASTIN, E. S., Economic geology of the feldspar deposits of the United States: 

U. S. Geof. Survey Bull. 420, 85 pp., 1910.

 Geology of the pegmatites and associated rocks of Maine, including 

feldspar, quartz, mica, and gem deposits: U. S. Geol. Survey Bull. 445, pp. 

26, 138-143, 1911.

CIRKEL, FRITZ, Mica, its occurrence, exploitation, and uses: Canada Dept. 

Mines, Mines Branch, 148 pp., 1905.

CLARKE, F. W., Mica: U. S. Geol. Survey Mineral Resources, 1883 and 1884, pp. 

906-912, 1885.

COLLES, G. W., Mica and the mica industry: Franklin Inst. Jour., vol. 160, pp.. 

391, 275, 327, 1905. Reprinted in book form.

CORTCILL, E. T., Notes on the occurrence, production, and uses of mica: Min, 

World, Mar. 25, 1905, pp. 323-324. ^

CKOSBY, W. O., and FULLER, M. L.. Origin of pegmatite: Am. Geologist, vol. 19r 

pp. 147-180, 1897.

DIXON, A. F., The India mica industry: Am. Inst. Min. Eng. Trans., vol. 45; 

pp. 94-112, 1913.

ELLS, R. W., Mica deposits of Canada: Canada Geol. Survey, Mineral Resources-- 

of Canada Bull. 869, 32 pp., 1904.

ENGINEERING, Mica insulation for steam pipes and boilers, Feb. 22, 1901.

FULLER, M. L., The occurrence and uses of mica: Stone, vol. 19, pp. 530-532r 

1899.

GALPIN, S. L., A preliminary report on the feldspar and.mica deposits of Georgia : Georgia Geol. Survey Bull. 30, 1915.

RENAULT, DENNIS, The Crown mica mine, Ouster City, S. Dak.; Min. and ScL 

Press, vol. 87, p. 181, 1903.

HOLLAND, T. H., Mica deposits of India: India Geol. Survey Mem., vol. 34, p( > 

11-121, 1902

HOLMES, J. A., Mica deposits in the United States: U. S. Geol. Survey Twentieth Ann. Rept., pt. 6 (contd.), pp. 691-707, 1899.

 The mica industry in 1900: U. S. Geol. Survey Mineral Resources, 1900,.

pp., 852-856, 1901. 

JEFFERSON, C. W., and DYER, A. H. S., Electrical uses of mica: Am. Inst, ElectEng. Trans., vol. 9, p. 798; and Sci. Am. Suppl., vol. 35, pp. 14238-14240, 1893. 

JONES, F. A., New Mexico mines and minerals; World's Fair Edition, pp. 259 

262, New Mexico Printing Co., Santa Fe, N. Mex., 1904. 

KEITH, ARTHUR, U. S. Geol. Survey Geol. Atlas, Mount Mitchell folio (No. 124),

1905; Nantahala folio (No. 143), 1906; Pisgali folio (No. 147), 1907, and

Roan Mountain folio (No. 151), 1907. 

KERR, W. C., The mica veins of North Carolina: Am. Inst. Min. Eng. Trans.,,

vol. 8, pp. 457-462, 1880. 

MINERAL INDUSTRY, Mica, 1915 and several years preceding. Published by

Eng. and Min. Jour., New York. 

MINING AND SCIENTIFIC PRESS, Mica in California, Feb. 4, 1905.

 Mica, occurrence and uses, Feb. 4, 1905, pp. 68-69.

PARKER, E. W., Mica: U. S. Geol. Survey Mineral Resources, 1893, pp. 748-755r

1894. 

PHILLIPS, W. B., Mica mining in North Carolina: Eng. and Min. Jour., vol. 45r

pp. 286, 306-307, 322, 324, 382-383, 398, 418, 436, 1888.

 Mica mining in North Carolina: U. S. Geol. Survey Mineral Resources,.

1887, pp. 661-671, 1888. 

PKATT, J. H., The mining industry in North Carolina: North Carolina Gcol.

Survey, 1900-1910.
BIBLIOGRAPHY. 6

PKATT, J. H., Mica: U. S. Geol. Survey Mineral Resources, 1901, pp. 873-878, and

1904, pp. 1175-1184.

PKOUTY, W. F., Mica in Alabama: Mines and Minerals, Dec., 1907. 

PULSIFEK, H. B., New Hampshire mica deposits near Grafton: Min. and Eng.

World, vol. 41, pp. 141-143, 1914.

RAND, T. D., Mica: Franklin Inst. Jour., 3d ser., vol. 79, pp. 190-192, 1880. 

RICE, C. F.,, Description of mica mining company in Grafton County, N. H.:

Min. and Sci. Press, Feb. 23, 1901. 

SCHMID, H. S. de, Mica, its occurrence, exploitation, and uses: Canada Dept.

Mines, Mines Branch, 2d ed., No. 118, 412 pp., 1912. 

SCOTT, H. K., On the occurrence of mica in Brazil and on its preparation for the

market: Inst. Min. Met. Trans., vol. 12, pp. 351-364, London, 1903; also in

Mines and Minerals, vol. 24, pp. 34-37, 1903, Scranton, Pa. 

SHALEE, N. S., Mica mines of New England: Tenth Census U. S. Mining,

1886, pp. 833-836. 

SHEPARD, C. U., Mineralogical journeys, etc. Acworth minerals: Am. Jour.

Sci., 1st ser., vol. 17, pp. 354-360, 1830. 

SIMMONS, JESSE, Mica in the Black Hills of South Dakota: Min. World, vol.

33, pp. 221-223, 1910. 

SLOAN, EARLE, Catalogue of the mineral localities of South Carolina: South

Carolina Geol. Survey Bull. 2, pp. 142-149, 1908. 

SMITH, A. M., Mica mining in Bengal, India: Inst. Min. Met. Trans., vol. 7,

pp. 168-174, 1899. 

SMITH, G. O., Mica: U. S. Geol. Survey Mineral Resources, 1905, pp. 1279-

1283, 1906. 

STEBBETT, D. B., Mica deposits of western North Carolina: U. S. Geol. Survey

Bull. 315, pp. 400-422, 1906.

 Mica deposits of South Dakota: U. S. Geol. Survey Bull. 380, pp. 382-397, 

1909.

 Mica deposits of North Carolina: U. S. Geol. Survey Bull. 430, pp. 593- 

638, 1910.

 Mica in Idaho, New Mexico, and Colorado: U. S. Geol. Survey Bull. 530,

pp. 375-390, 1913. 

 Some deposits of mica in the United States: U. S. Geol. Survey Bull.

580, pp. 65-125, 1915,

STOKES, RALPH, India mica industry: Min. World, May 19, 1906, pp. 606-607. 

STONIEE, G. A., Mica mining in Nellore (southern India) : Min. Reporter, Feb.

9, 1905, p. 150. 

VAN HISE, C. R., A treatise on metamorphism: U. S. Geol. Survey Mon. 47,

pp. 720-728, 1904. 

WALKER, T. L., Percussion figures of mica: Am. Jour. Sci., 4th ser., vol. 2, pp.

5-7, 1896.

 Crystal symmetry of the mica group: Am. Jour. Sci., 4th ser., vol. 7, 

pp. 199-204, 1899.

WATSON, T. L., Mineral Resources of Virginia, The Virginia Jamestown Exposition Commission, 1907, pp. 278-285.

 Annual report of the mineral production of Virginia during 1908: Virginia Geol. Survey Bull. 1-A, pp. 101-105, 1909.

WATTS, A. S., Mining and treatment of feldspar and kaolin in the southern 

Appalachian region: U. S. Bur. Mines Bull. 53, 1913.

WELLS, J. F., Occurrence of mica in south Norway: Inst. Min. Met. Trans., 

vol. 7, pp. 334-340, 1898-99.
4 MICA DEPOSITS OF THE UNITED STATES.

GEOLOGY. 

GENERAL FEATURES.

Mica is a very common mineral and occurs in igneous, sedimentary, 

and metamorphic rocks, usually as small scattered scales, though 

some rocks are composed almost entirely of mica. Large crystals of 

muscovite and biotite, the two most common forms of mica, are found 

in pegmatite (a coarse-textured igneous rock) and large crystals of 

phlogopite, a less common form, are found in pyroxenic rocks. As 

muscovite and a little biotite are the only forms of mica found in 

 commercial sizes in the United States pegmatite will receive special 

attention in this report.

Mica-bearing pegmatites are confined to areas of crystalline rocks, 

especially ancient metamorphic rocks. The absence of areas of such 

rocks in any region indicates the absence of valuable deposits of 

mica, but, on the other hand, their presence does not indicate the 

presence of mica; it only indicates that mica may be found in them.

A study of the geologic map of North America 1 shows that 

deposits of mica may occur in the following regions of the United 

States: The eastern Appalachian region from Alabama to New York 

and the New England States; northern Wisconsin, Michigan, and 

Minnesota and the region including corners of Minnesota and Iowa 

and part of South Dakota; southeastern Missouri; the Black Hills 

of South Dakota; the Rocky Mountain region from New Mexico to 

Montana; and many smaller more or less isolated areas in nearly all 

the Western States from Texas to California and Washington. The 

same map shows large areas in which a mantle of younger sedimentary rocks that ranges in thickness from hundreds to thousands 

of feet covers the older crystalline rocks, and in which, accordingly, 

mica deposits are not likely to be found.

The crystalline rocks, composed of metamorphosed sedimentary 

rocks and granitoid intrusions, were formed at least 5,000 feet below the surface and probably at much greater depth. The pegmatites, which are generally composed of shoots from granitic 

rocks, are also supposed to have been formed deep in the earth's 

crust. These rocks accordingly are now found ir regions where 

erosion has been sufficiently prolonged to remove the overlying unmetamorphosed formations and to expose the crystalline rocks and 

the mica-bearing pegmatites.

The crystalline gneisses and schists have received their texture 

and composition either from regional metamorphism or from contact 

or injection metamorphism or both.

1 Willis, Bailey, and Stose, G. W., Geologic map of North America : U. S. Geol. Survey, 

1911.
BIBLIOGRAPHY. . 0

.Regional metamorphism in general has produced foliated rocks 

that do not contain large quantities of granite or feldspathic material, such as ordinary mica, quartz-mica, garnet, and ky unite gneisses 

and schists. Contact or injection metamorphism has produced considerable feldspathic material in gneisses and schists. This material consists in some places of granite, in others of pegmatite, and 

in still others of intermediate phases .of rock. In a few places there 

is less feldspar and much quartz and mica. This granite or pegmatitic material has been injected into the gneisses and schists, cutting them both parallel to and across the bedding. In places this 

pegmatization is so thorough that mica gneisses become strikingly 

like granite gneisses.

PEGMATITE.

OCCURRENCE.

A discussion of the occurrence of muscovite mica means practically 

a discussion of the occurence of pegmatite, for mica is found in a 

great many types of this rock. Pegmatite occurs as intrusions of 

bulky masses, in veinlike or dikelike sheets, in lenses, and in various 

irregular-shaped deposits. The deposits range in thickness from 

a small fraction of an inch to more than 200 feet. The larger masses 

resemble granitic intrusions. Some of the smaller deposits are more 

like veins.

Man}^ of the more persistent pegmatites occupy straight fissures 

that hold their direction for long distances; others are folded with the 

country rock or bent and twisted into various shapes. Some- arc 

more or less conformable with the bedding of the gneisses and 

schists and are therefore subject to the deformation of the country 

rock. Some large deposits cut across the foliation of the country rock 

and send out forks or apophyses conformable with strata of the inclosing gneiss or schist. In some deposits parallel and overlapping 

sheets and lenses of pegmatite conformable with the foliation of 

the country rock are common. Smaller beds or veins of pegmatite 

mny cut across the strata and connect larger deposits. Locally there 

may be an elbowing or bulging out on one wall of the pegmatite but 

no similar irregularity on the other wall. Lens-shaped bodies may 

lie in the same plane of bedding or schistosity and be connected by 

smaller streaks or stringers of pegmatite or by mere seams in the 

rock.

The irregularities of pegmatite and the consequent difficulties in 

mining mica from it are well illustrated in clean rock exposures, cuts, 

or quarry faces where pegmatizer] gneiss or schist has been exposed. 

The lenticular shapes, pinching and swelling, crumpling, forking, . 

111375 23 2
6 . MICA DEPOSITS OF THE UNITED STATES.

folding, and faulting seen at such places are nearly duplicated in some 

of the larger deposits of pegmatites opened for mica. Such small 

bodies of pegmatite may grade into larger ones that contain mica of 

commercial value Occasionally the two can be seen at the same 

locality.

The minimum size of pegmatite deposits that can be "profitably 

worked for mica can not be definitely stated. A deposit measuring 

only 2 feet across may be worked if it is rich, regular, and continuous 

for a long distance. It seldom pays to remove all the pegmatite 

from a deposit that is more than 25 feet thick to obtain mica alone, 

but if the deposit is worked for other minerals also, such as feldspar 

or gems, mining for mica may be profitable.

Horses, or inclusions of wall rock, are common in pegmatite. 

Some of them form bands or sheets parallel to the walls, and the 

schistosity of the bands is also parallel to the walls. They range 

in thickness from an inch or two up to several feet, and their length 

may be many times their width. Others occur as irregular-shaped 

masses, from a few inches to several feet in thickness. If the bedding has been preserved it may lie at any angle with that of the 

inclosing wall rock. In some places the horses are partly pegmatized 

by ramifying streaks of pegmatite and by the development- of considerable feldspar and quartz. In such places no sharp line can 

be drawn between the pegmatite and the original horse.

In pegmatite, as in granite, the essential constituents are feldspar 

and quartz, which are accompanied by mica and other accessory 

minerals.

Hornblende is rather common in granite but is less so in pegmatite. 

Orthoclase and microcline are the most common varieties of feldspar 

in pegmatite. In many places, however^ a variety of plagioclase, 

either albite or oligoclase, makes up part or all of the feldspar. The 

feldspar occurs in masses and rough crystals, some of which have 

a diameter of several feet.

Quartz assumes various forms and positions in the pegmatite. 

In many places it bears much the same relation to the feldspar and 

mica as in granite, the three minerals being thoroughly mixed with 

one another; but the individual grains are many times larger than 

in ordinary granite. Not uncommonly the quartz and feldspar 

assume the .texture of a graphic granite in a part of the pegmatite. 

Another common feature is the occurrence of large separate masses 

of quartz in various positions in the pegmatite. Such masses may 

be irregular in form and may be but little influenced by the shape 

of the pegmatite or the inclosing wall. Many of them, however, lie 

in bands or sheets parallel to the walls, and one or more of these 

quartz bands may constitute varying proportions of the pegmatite.
GEOLOGY. (

Their thickness ranges from a fraction of an inch up to 6 feet or 

more. Many of them are lenticular, their length ranging from four 

or five to twenty or more times their thickness. At many places 

these quartz streaks or veins are persistent through the whole length 

of the pegmatite exposed. Some of them inclose bodies of feldspar 

or mica; others do not. The quartz of these segregations is massive 

and generally granular, though at some places it may be crystallized. 

If crystallized, it may be translucent or clear and of a dark smoky 

or light color. It is generally rather pure and does not contain 

much feldspar or mica.

Some masses of pegmatite contain large bodies of graphic intergrowths of potash feldspar and quartz, which form what is called 

"graphic granite." (See PL I.) 2 "Graphic granite" is abundant 

in pegmatites that are mined for feldspar and gem minerals but is 

not plentiful in the pegmatites that are of greatest value for mica;.

Muscovite is the most common mica in pegmatite and is the principal variety mined in the United States. Biotite occurs in moderate 

quantity in a few deposits and in smaller quantity in many others. 

Where muscovite and biotite occur together in a deposit the muscovite 

is generally clear and of good color. Again, mica from deposits 

in rocks that contain abundant ferromagnesian minerals, such as 

hornblende or biotite gneiss and schist, is generally clear and of 

light color. Mica from pegmatite in granite or closely associated 

with it, with few ferromagnesian minerals, is generally dark, and 

much of it is " specked."

Mica occupies various positions in pegmatite. If the rock has a 

typical granitic texture the mica may be evenly distributed through 

it, but more commonly the larger crystals are either clustered at 

intervals through the " vein," in places connected by streaks of small 

crystals, or are collected along one or both walls of the pegmatite, 

some of the crystals being partly embedded in the wall rock. If 

there is a quartz streak in the pegmatite the mica occurs on either 

or both sides of it. The mica may be partly embedded in the quartz 

or be scattered through the remaining portion of the pegmatite, 

which generally is composed largely of feldspar.

The proportion of mica to the other minerals of the pegmatite is 

variable, ranging from less than 1 per cent to possibly more than 10 

per cent, with local enrichments where the mica may compose more 

than 50 per cent of the "vein" for short distances. All the mica 

of the pegmatite is not suitable for splitting into sheets. In some 

deposits the mica occurs in aggregations or bunches such as "mica 

capping" and "solid" mica. "Mica capping" is a miner's term

"Bastin, E. S., Geology of the pegmatites and associated rocks of Maine: U. S. Gcol. 

Survey Bull. 445, pi. 7, 1911.
O MICA DEPOSITS OF THE UNITED STATES.

for an aggregation of mica and quartz, with or without feldspar and 

other minerals, in which the mica is small or occurs in distorted 

crystals so as to be of little commercial value. The mica does not 

invariably form a capping to a regular "vein" below or near by, 

for some such deposits carry nothing but "mica capping." The 

mica of "mica capping" commonly occurs in "wedge" shaped 

blocks with A structure, in many places is more or less distorted or 

twisted, and may contain inclusions of quartz. Plate II, 4, shows 

a block of " mica capping."

Aggregations consisting wholly or almost wholly of mica crystals 

occur in some of the pegmatites. Some of these masses measure 

several feet across. The crystals composing such massive mica'range 

from a small fraction of an inch to 2 inches or more in diameter 

and thickness. Massive mica generally occurs in irregular-shaped 

bodies without definite arrangement in the pegmatite. A mass of 

large mica crystals, of the " solid " mica variety, is shown in Plate 

II, #.3

A large number of valuable minerals have been found in the 

pegmatite deposits of the United States. Some of these minerals 

are valuable for commercial use or as specimens; others are of interest only because they show one of the modes of their occurrence. 

The minerals of chief value in most of the pegmatite mined are 

feldspar and mica, but quartz also is sometimes saved. Some bodies 

of pegmatite contain gem minerals, such as beryl (emerald, blue and 

golden beryl, aquamarine, etc.), tourmaline (of various colors), 

spodumene (hiddenite and kunzite), garnet (almandite and 

spessartite), topaz, quartz (crystal, smoky, amethyst, colorless, and 

rose), amazonstone, and moonstone. Among the commercial minerals, besides mica are cassiterite (tin ore), amblygonite, lepidolite, 

graphite, zircon, monazite, and a number of rare-earth minerals. 

Other valuable minerals found in pegmatite mined for mica are beryl, 

amazon stone, moonstone, uranium minerals, and mineral specimens,

GENESIS.

The origin of pegmatites has been a subject of much discussion. 

Some geologists contend that all pegmatites were formed by intrusions of igneous magmas; others, that they were vein deposits. Many 

now believe that they have been formed by both processes, one mode 

of formation grading into the other, and the possibility that there 

has been such a gradation will become more evident after the conditions producing pegmatite magmas or solutions have been considered.

Pegmatitic magmas and solutions, which are believed to represent 

the final stages of solidification of masses of granite magma, have been

3 Bastin, E. S., op. cit, pi. 9.
GEOLOGY. 9

formed by the accumulation of water vapor and other mineralizing 

solutions or gases in parts of the still molten magma. This accumulation is caused by the occlusion of these vapors from the anyhydrous 

minerals that are crystallizing out of the magma. The proportion of 

vapors to other mineral matter in solution increases as crystallization 

proceeds, and the remaining magma becomes more fluid through the 

presence of the vapors. In this way the highly fluid magma or solution accumulates in large quantities within the granite masses. When 

these partly solidified granite masses are fractured by earth movement this highly fluid aqueo-igneous material is forced out through 

the fractures in the granite mass into the surrounding country rock. 

Some parts of this material remain in the fractured planes and 

crystallize out as intrusive pegmatite. Other parts travel through the 

fractured zones depositing vein material. Such minerals as mica 

and feldspar crystallize out from these magmatic solutions and leave 

an increased proportion of mineralizing fluid and vapors to accompany the silica still in solution. The silica is then carried beyond 

the zone in which the pegmatite is deposited and forms quartz veins.

The above outline of the method of forming pegmatite agrees Avell 

with facts observed. Pegmatite deposits that fill fractures in the 

parent granite mass and deposits in the country rock near such a mass 

are highly feldspathic and resemble dikes. Pegmatite deposits 

farther away from the granite mass contain a proportion of quartz 

segregations that increases with distance from the mass, and these 

segregations tend to assume veinlike forms within the pegmatite. At 

a still greater distance less mica and feldspar appear and the deposits 

grade into ordinary quartz veins.

The blending between the conditions of fusion and solution conceived to exist under heat and pressure, such as prevail in deeply 

buried granite magmas where water is present in considerable quantity, has been well set forth by Van Hise,4 Crosby and Fuller,5 and 

Williams.6 As stated by Van Hise, given the two conditions, a 

magma and a solution with no sharp line of demarcation betAveen 

them^we may expect to have injections of dikes and aqueous cementation, which grade into each other and betAveen which no sharp 

distinction can be drawn.

It is difficult to conceive that pegmatite may be formed by injection into gneissic rocks, as an ordinary magma, in streaks or bands 

a fraction of an inch thick in many places having no visible connection with other bodies of pegmatite. On the other hand, it is 

easy to conceive that a solution might be forced through the smallest

4 Van Hise, C. R., A treatise on metamorphism : U. S. Geol: Survey Mon. 47, 1904. 

8 Crosby, W. O., and Fuller, M. L., Origin of pegmatite: Am. Geologist, vol. 10, 1897. 

« AATilliams, G. H., General relations of the granitic rocks in the Middle Atlantic Piedmont Tlateau : U. S. Geol. Survey Fifteenth Ann. Kept, 1895.
10 MICA DEPOSITS OF THE UNITED STATES. ;

fractures or might work its way between the mineral particles and 

deposit its load. This process would not require temperatures so 

high, either in the solution or in the country rock, as those required 

for the injection of a magma in order that it might not be cooled so 

quickly as to prevent coarse crystallization. The possibility that 

the smaller deposits of pegmatite may be formed by the injection of 

a highly fluid aqueo-igneous magma is not denied, especially if the 

magma approaches closely the conditions of a solution, but it is 

thought that the theory of its formation by aqueous processes affords 

a simpler and therefore more reasonable explanation.

Eock masses are probably pegmatized either by recrystallization 

due to aqueous agencies or by the addition of more material from 

solutions passing through the formations. In the first process water 

occluded in the rock, aided by the heat generated during regional 

metamorphism, may have caused recrystallization and consequent 

pegmatitic texture. In the second process pegmatization may have 

been caused by solutions that were forced through the rock along 

cracks, seams, or bedding planes and there deposited their load. 

Where the pegmatized rock contains much feldspar the solutions 

were probably of magnetic origin, and one generally does not have 

to look far to find intrusive granite in the neighborhood of a deposit 

of pegmatite.

. It is difficult to decide whether some deposits of pegmatite were 

formed as dikes or as veins, but the conditions in others clearly 

point to the one or to the other mode of origin. There seems to be 

no objection to assuming an intrusive origin for most pegmatites 

which have a typical granitic texture and in which none of the constituent minerals are separated out into sheetlike masses parallel to 

the walls, especially those that are more persistent in extent in 

regions where granite intrusions are large or plentiful. On the 

other hand, deposits that'are banded with veinlike sheets of quartz 

parallel with the walls, and smaller irregular masses, streaks, lenses, 

augen, or balls that have no visible connection with other bodies of 

pegmatite, were probably formed from solutions. Some pegmatites 

were possibly formed in part by the intrusion of a magma and later 

modified by the passage of solutions from the same source.

The mica-bearing pegmatites of the United States were probably 

formed both as intrusions and as veins, and include many intermediate types, but it is not possible to define the types that will be 

found in any particular region, for more than one type may be 

found in the same region. E. S. Bastin 7 shows that most of the 

pegmatites mined for commercial minerals in Maine are of probable 

intrusive origin. The writer's observations confirm this conclu7 Geology of the pegmatites and associated rocks of Maine, including feldspar, quartz, 

mica, and gem deposits: U. S. Geol. Survey Bull. 445, 1911.
MINEBALOGY. 11

sion and lead to a similar one regarding the deposits in New Hampshire and Connecticut. The pegmatites mined for mica in South 

Dakota, however, possess many features of dikes. The deposits of 

the southern Appalachians present features of both intrusions and 

dikes, but most of them would probably be classed as intrusions.

MINERALOGY.

COMPOSITION.

The term mica as used in mineralogy includes a number of minerals 

that have certain physical characteristics in common, but it is applied 

commercially to only a few of them, which are valuable because of 

these physical properties. In mineralogy several species of mica are 

recognized, among them muscovite, phlogopite, biotite, lepidomelane, 

lepidolite, paragonite, zinnwaldite, and roscoelite. These minerals 

are aluminum silicates, whose bases include different elements. Muscovite is an orthosilicate of aluminum and potassium; phlogopite 

contains in addition magnesia and a little fluorine; lepidomelane contains much ferric iron and a little magnesia; biotite contains iron 

and magnesia; lepidolite is a lithia-bearing and paragonite is a 

soda-bearing mica corresponding to the potash variety, muscovite; 

zinnwaldite is a lithia and iron bearing mica; and roscoelite is a vanadium-bearing mica.

These are two groups of micaceous minerals that do not have all 

the physical properties common to the true micas, especially flexibility and elasticity of the cleavage sheets the clintonites, or brittle 

micas, and the chlorites. The clintonites, of which margarite is a 

typical variety, are characterized by brittle cleavage sheets. The 

chlorites are greenish from the presence of ferrous iron and are 

generally characterized by inelastic cleavage plates.

CRYSTALLOGRAPHY.

The micas have generally been regarded as belonging to the monoclinic system, with approximately hexagonal crystals, but detailed 

studies have shown, according to T. L. Walker,8 that probably all the 

micas except muscovite are really triclinic. Evidence for this conclusion was obtained both by measurement of the angle between the clinopinacoid and the optic axis and by etch figures. These methods 

yielded similar results in similar minerals. The approximately 

hexagonal symmetry of the crystals of different micas is indicated 

by the nearly hexagonal outline observed in many prisms by ruled 

and A mica and by percussion and pressure figures.

8 Crystal symmetry of the minerals of the mica group: Am. Jour. Sci., 4th ser., vol. 7, 

pp. 199-204, 1899.
12 MICA DEPOSITS OF THE UNITED STATES.

A percussion figure is readily obtained by striking a plate of 

mica a sharp blow with a rather blunt punch. The best figures 

are obtained in sheets 0.25 to 0.50 millimeter thick. A moderately firm background, such as a paper-covered book, is desirable. 

A percussion figure is a six-rayed star formed by three cracks or 

cleavages that cross a plate of mica at a common point. In making 

such percussion figures in mica, part or all of another six-rayecl 

star, the rays of which fall between those of the percussion figure, 

is occasionally obtained. This is called a pressure figure and is 

not so readily obtained as a percussion figure. Where complete 

percussion and pressure figures are obtained together a 12-rayed 

star is produced.

One of the cracks of a percussion figure is parallel with the clinopinacoid of the mica crystal, and the other two meet each other

at angles ranging from 52° 53' in 

muscovite to 63° 28' in phlogopite, 

as determined by T. L. Walker.9 

In biotite the three cracks meet at 

angles closely approximating 60°. 

Walker found that the angle between the two cracks not parallel 

with the clinopinacoid (x, fig. 1) 

ranged from 52° 53' to 55° 57' in 

muscovite from seven different localities. T. H. Holland 10 found 

that this angle was larger in 

Indian muscovite when the percussion figure was obtained at; 

higher temperatures. The same 

mica yielded angles 2|° to 3° 

larger at 300° C. than at ordinary temperatures. Holland's measurements showed that the angle x 

at ordinary temperatures ranged from 53° to 55° in muscovite from 

four different localities in India. Measurements made by the writer 

on muscovite from several States of the United States showed that 

the angle x ranged from 53£° to 55°.

The cleavages of a percussion figure in mica cut the laminae formed 

by the perfect basal cleavage at high angles. Kough measurements 

made on the percussion cleavages showed angles of 60° to 70° with the 

basal cleavage. The cleavage rays or cracks extend farther from 

the center of the percussion figure in the lower laminae of the mica 

than in the upper laminae, or near the surface where the blow is 

struck. For this reason the best plates for the study of the percussion figures can be obtained by splitting them from the bottom

0 Percussion figures of mica : Am. Jour. Sci., 4th ser., vol. 2, pp. 5-7, 1896. 

10 Mica deposits of India: India Geol. Survey Mem., vol. 84, p. 21, 1902.

FIGURE 1. Diagram showing position of 

rays of the percussion and pressure 

figures in a crystal of muscovite mica. 

(After Holland.) See text for explanation.
MINERALOGY. ' 13

of a sheet of mica after the figure has been made. Thin laminae 

exhibit sharper figures. The rays of an individual percussion figure 

range in length from a millimeter or so to 2 centimeters. A cleavage 

crack can be carried across a sheet of mica by making a series of 

successive percussion figures along the line of one of the rays. Percussion figures vary greatly, even when obtained in the same sheet 

of mica and under apparently similar conditions. In some laminae 

one or more rays are only imperfectly developed or are absent, in 

others all six rays are prominent, and in a few only three alternating rays occur, radiating from a common point. A cleavage 

sheet from a mica crystal, with percussion figures, is shown in 

Plate III, A.

A pressure figure, like a percussion figure, is composed of cleavage 

cracks cutting across the laminae of the mica at wide angles. One 

of the rays is perpendicular to the clinopinacoid and accordingly 

perpendicular to the principal ray of the percussion figure. 

Holland n states that the pressure-figure rays form ^angles of 

about 60° with each other, but this statement is difficult to confirm, 

for pressure figures Avith rays sufficiently distinct to measure closely 

are rarely obtained. In some of the many specimens of muscovite 

from the United States experimented on by the writer the rays of 

the pressure figures were not perfectly straight, and in others those 

on opposite sides of the center were neither in alinement nor 

parallel. In one specimen, where the six rays of the pressure figure 

were obtained, measurements by the writer gave angles of 59°, 60°, 

and 61°, with an average of 60° between the rays. In other 

specimens, where only partial pressure figures were obtained, the 

angles that were measured ranged from 55° to 65°. In a specimen 

of A mica having the six rays of what was apparently the pressure 

figure, developed angles of approximately 50°, 60°, and 70° were 

measured. Some of the rays on opposite sides of the center of this 

figure were not in alinement.

Most of the pressure figures obtained for examination were combined with percussion figures, the two having a common center. 

Measurements made on many of these gave results approximating 

those obtained by Holland 12 with India micas, summarized below 

and illustrated in figure 1.

1. The principal ray of the percussion figure EE' lies in the plane of symmetry and at right angles to the optic-axial plane.

2.. The principal ray is cut perpendicularly by the ray PP' of the pressure 

figure, which lies in the optic-axial plane.

3. The angle K between the rays FF' and GG' averages 53° 55' (nearly 54').

4. The remaining angles of the percussion figure are, to the nearest degree, 

each 63°.

11 Holland, T. H., op. cit, p. 19.

1= Holland, T. H., op. cit., pp. 19-20.
14 MICA DEPOSITS OF THE UNITED STATES.

5. The rays of the pressure figure intersect one another as nearly as can be 

measured at angles of 60°.

6. The subordinate rays of the percussion figure meet the subordinate rays 

of the pressure figure at angles of 93° and 33°.

7. The etch figures produced by the action of hydrofluoric acid or by fused 

potash are bisected symmetrically by the principal ray EE' of the percussion 

figure.

PHYSICAL PROPERTIES.

The first prominent characteristic of the minerals of the mica group 

is cleavage. All the micas have a pronounced basal cleavage, generally almost perfect, by which they can be split into thin sheets. 

The true micas yield cleavage sheets that are tough, flexible, and 

elastic. Other properties possessed in common by the micas are 

similarity in crystallization, other cleavages or partings called " rulings," brilliancy or high luster, transparency in some varieties, color, 

comparative softness, and relatively great resistance to the conduction of electricity and heat.

Several of these properties, such as toughness, flexibility, and elasticity of the cleavage sheets combined with transparency .in some 

varieties, nonconductivity of electricity and heat, and brilliancy of 

the cleavage faces make mica valuable.

Biotite and muscovite are the most common types of mica. Biotite 

is a dark-colored mica, generally brown to brownish black or green, 

and is opaque to translucent in all but thin sheets. The folia are 

flexible and elastic, but less so than those of muscovite. Biotite is 

commonly found in small plates and crystals as a rock constituent, 

but some occurs in sheets several inches to a foot wide.

Muscovite is transparent and light-colored when split into thin 

sheets, but sheets one-sixteenth of an inch or more thick may be colorless, gray, yellow inclining to amber, red, brown, or green. Thin 

sheets are called " white" mica, but sheets of sufficient thickness to 

show strong color are spoken of, according to color, as "rum," 

" ruby," " smoked," or " green" mica. Muscovite occurs both in the 

form of small scales as a common constituent of many rocks and as 

large crystals of less widespread but still rather common occurrence.

Phlogopite commonly ranges in color from yellow to brown and 

black. Sheets less than one-sixteenth of an inch thick may appear 

amber-yellow to brown, reddish brown, or black. Some of it has a 

coppery appearance. Phlogopite is generally less transparent than 

muscovite, owing to the presence of many minute inclusions.

The other varieties of mica will not be considered in this report.

Mica mined for commercial use is commonly found in rough 

blocks, some of which have irregularly developed crystal faces. The 

faces are not usually as many as would be required to complete the 

simplest figure, and their surfaces are generally very rough. A
MINERALOGY. 15

large part if not all of a block of mica usually has a ragged outline 

and is without plane surfaces, but fairly well developed hexagonal 

or rhombic prisms have been observed in crystals of mica weighing 

.hundreds of pounds.

Rough crystals of mica, or " books," as they are called in the Western States, do not split perfectly until the outer shell of etched and 

sometimes partly crushed mica has been removed by rough splitting 

or cleaving the large book into sheets an eight of an inch thick or 

less and trimming the edges with a knife held at a small angle with 

the cleavage. After the tangled outside edges of the sheets have 

been removed, further splitting is easy, because the cleavage of mica 

is nearly perfect. By grinding a wedge-like edge on the sheets 

and using a thin, sharp knife mica can be readily split into'sheets 

less than a thousandth of an inch thick, and some of the thin splittings prepared in India measure only about a sixteen-hundredth of 

an inch.

Mica has a number of physical peculiarities due to crystal structure, color, and inclusions, to which miners and dealers have applied 

certain descriptive terms. Structural peculiarities give " ruled " or 

<( ribbon," "A," "hair-lined," "fishbone" or "herringbone," 

41 feather," " horsetail," " tanglesheet," and " wedge " mica; the different colors give " rum," " ruby," " amber," " white," and " black " 

mica, though brown, green, and greenish-brown colors are also seen; 

and inclusions give " specked," " black," and " clay-stained "' mica.

Ruled or ribbon mica is formed by more or less clean, sharp parting 

planes that cut through the crystals at an angle of nearly 67° with 

the base or cleavage surface. This parting passes entirely through 

some crystals and extends only part way across the face of others 

or does not cut through their entire thickness. The trace of the 

ruling planes corresponds in direction to the. rays of the pressure 

figure in mica. Though a cleavage resembling ruling may be produced by making a series of percussion figures along the line of one 

of the rays, it is evident that ruling planes do not correspond to the 

lines of weakness represented by the percussion figure, for.the two 

make angles of 25° to 35° with each other. On the other hand, the 

ruling planes fall in the same directions as the rays of the pressure 

figure and probably occur along the lines of weakness represented 

by them. Plate III, #, illustrates ruled or ribbon mica. (See also 

Pi. VI, 1.) Ruling lines occur more commonly in one series of 

parallel lines in mica. In some specimens these parting planes extend in two or even in three directions, and their traces on the cleavage planes make angles of about 60° with each other, dividing the 

mica sheets into small triangular plates. Some large blocks or crystals of mica that are otherwise of excellent quality have been made
16 MICA DEPOSITS OF THE UNITED STATES.

practically worthless by extensive ruling. Ruling is so extensive in. 

some mica that it has cut the mineral into thin strips and slivers of 

hair-like fineness.

In A mica two series of lines or striations cross the sheets of mica 

at an angle of about 60°, generally forming a V. A part of a mica, 

crystal exhibiting the A structure is shown in Plate IV. A. (See also 

PL II; PI. VI, 2, 3.) The third striation necessary to complete the 

letter A is absent, but the miners have nevertheless called this variety 

A mica. In some pieces these striations are caused by wedge structure in the crystals, and the sheets that have wedged out may or may 

not be replaced by detached sword-bladelike strips. In other pieces 

the striations are caused by small folds or crenulations in the sheets of 

mica. The A striations have the same orientation in the sheets asthe ruling lines that is, their position corresponds to the rays of 

the pressure figure. Ruling is seen in some A mica. If the striations are caused by small folds the mica may split across them and 

the sheets may have some commercial value, though not so high as 

that of perfect plates; if they are due to the wedging out of sheets,, 

only plates between the A lines can be used commercially, and the 

value of large crystals is thus materially reduced. A crystal of 

mica in which the striations extend in one direction only is called 

" hair-lined."

In the " fishbone " or " herringbone " structure, striations with or 

Avithout ruling and apparently identical with the A lines of mica 

make angles of about 120° with each other and join at a center line 

or spine. This forms a structure resembling a feather or the skeleton 

of a fish. Plate IV, B. illustrates a block of fishbone or herringbone 

mica. (See also PI. VI, 4.) The same variety has been called 

u horsetail" mica by the miners in Alabama. Mica with fishbone 

structure has no commercial value as sheet mica but is used as scrap 

for grinding.

In "tangle-sheet " mica, a name little used, the laminae split well in 

some places but tear in others. This imperfection is caused by the 

intergrowth of parts of one sheet with another, and may extend half 

an inch or more through some crystals, making apparently sound 

material valueless or nearly valueless as sheet mica.

In " wedge " mica the crystals are thicker on one side than on the 

other. Wedge structure is common in A and fishbone or horsetail 

mica and occurs also in plate mica. In plate mica the difference in 

thickness on opposite edges may be greater than half an inch in a 

crystal 3 inches in diameter. In A and fishbone mica the angles of 

the wedge may be as large as 30°. Plate V, from Bastin, shows a 

crystal of wedge mica which has also the fishbone structure. Wedge 

structure is due to an unequal development in the width of the
MINERALOGY. 17

laminae. Some of the laminae extend across the entire width of the 

crystal, but others do not, and generally these short laminae are not 

matched by similar laminae extending from the opposite edge, so that 

the crystal is thicker on one side than on the other, and not uncommonly wedge-shaped sheets of quartz are included between the 

laminae of such a crystal.

The words describing the color of mica are self-explanatory, but 

the miners and dealers ordinarily consider the color of sheets a sixteenth of an inch or more in thickness. Such colors as rum, ruby, 

and green seen in the thicker sheets practically disappear after the 

mica has been split into thin sheets. The material is then called 

" white " mica to distinguish it from Canadian phlogopite or amber 

mica. By black mica the miners generally mean muscovite specked 

with magrtetite, as described below, but by some miners dark-brown 

to black biotite is also called " black " mica. Rum, ruby, green, and 

the lighter-colored micas make the best grades of white mica for 

glazing. Dark-brown and brownish-green mica has to be split much 

thinner than rum and light-green mica to gain the desired transparency and is therefore generally classed as "No. 2," even when 

flawless and clear.

Some muscovite shows variations in color that accord with 

crystal structure. The variations generally appear in bands that 

follow the outline of the crystal. Thus, in looking through the mica 

one may see a dark rum-colored center surrounded by a fringe of light 

rum or yellow having a hexagonal or rhombic outline; or the center 

may be light and the border zone dark. (See PL VI, 5.) In some 

sheets there are alternating bands of varying color.

The various kinds of structure found in mica are illustrated in 

Plate VI. The position of the percussion figure is shown in most of 

the diagrams.

The pleochroism of muscovite and other transparent micas as 

strong and may be well observed in small crystals that have prism 

planes sufficiently smooth to transmit light. Crystals of such mica 

viewed edgewise are far more transparent than sheets of the same 

thickness. The color is also very different in these two directions. 

Some specimens of muscovite show a dark rum color perpendicular 

to the cleavage and yellowish to greenish yellow parallel with the 

cleavage.

Muscovite containing inclusions of spots or particles of different-colored minerals betAveen the laminae is called specked or sometimes black mica. Magnetite is the most common inclusion and 

occurs as black to brown dendritic tufts arranged in definite lines 

or patterns corresponding to the crystal structure of the mica or
18 MICA DEPOSITS OF THE UNITED STATES.

scattered irregularly through the sheets. Plate VII, J., shows heavilyspecked mica and #, slightly specked mica. These tufts of magnetite are very thin and rarely penetrate far into a sheet of mica.. 

The dark-brownish color of many of these spots is due to the translucency of the thin films of magnetic iron. Some of the streaks inthe mica are parallel to the rays of the percussion figure and othersare apparently parallel to the rays of the pressure figure, as shown 

in figures 6 and 7 of Plate VI.

Each spot owes its dendritic appearance to the arrangement in lines 

of small particles of magnetite, some of which follow the rays of 

the percussion figure. From these lines of particles other particles; 

branch off at more or less definite angles. Figure 8 of Plate VI 

is an enlarged sketch of such a dendrite, being five to ten times the 

diameter of an ordinary dendrite. That the black dendrites aregenerally magnetite can be proved by cutting out thin films of mica 

containing them and testing with a magnet. By decomposition the 

magnetite is partly or entirely altered to hematite or limonite and 

the specks become red or yellowish brown. In this way striking 

patterns in color are produced, which were once thought to be inscriptions made by the aborigines, and which gave rise to the name 

"hieroglyphic" mica. Still more delicate markings due to the 

other inclusions also resemble hieroglyphics. A specimen bearing^ 

such markings is illustrated in Plate VIII, A.

Among other inclusions found in mica are garnets, some of which 

are in flattened crystals ranging in thickness from that of paper to 

one-tenth of an inch and reaching a diameter of one-third of an inch. 

Two small garnets of this kind are shown in Plate VIII, B.

Crystals or sheets of biotite may be included in muscovite crystals 

or vice versa, the two micas generally occurring in parallel intergrowths and having a common cleavage plane. A unique specimen 

of biotite inclosing a rhombic crystal of muscovite with a common 

cleavage plane is shown in Plate VIII, G. The muscovite crystal 

narrows down abruptly from a rhomb with a side 1£ inches long to a 

rhomb with a side only a quarter of an inch long and a thickness of an 

eighth of an inch. The percusion figures of the two micas have their 

principal rays approximately perpendicular to each other and their 

optic axial planes approximately parallel.

In the zone of surface weathering, especially within a few feet of 

the surface, mica crystals may be clay stained by the penetration of 

muddy water between the laminae. The solutions penetrate large 

areas of crystals and work in between many of the laminae, greatly 

damaging the value of the mica. The clay staining is generally less 

marked in mica obtained at some distance from the surface and is, 

absent where mining reaches hard unaltered vein matter.
U. S. GEOLOGICAL SURVEY

SPECIMEN OF "GRAPHIC GHAMIli, A GRAPHIC IMTERGROWTH UK 
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE II

A. MICA "CAPPING.' 

M, mica; Q, quartz.

B. SOLID MICA, CONSISTING OK AGGREGATES OF "WEUUK" A.\U A MICA.
V. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE lit

A. CLEAVAGE SHEET FROM MICA CRYSTAL, SHOWING 

PERCUSSION FIGURES.

B. SPECIMENS OK "HULKD MICA," SOME "RULED" INTO 

"RIBBONS."
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE IV

A. FRAGMENT OF CRYSTAL OF MICA SHOWING A STRUCTURE.

B. MICA CRYSTAL SHOWING "FISHBONE" OR "HERRING-BONE' 

STRUCTURE.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE V

A

MICA CRYSTALS SHOWING "WEDGE" AND "FISHBONE" STRUCTURE.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE VI

3 4 

CLEAVAGE PLATES OF MICA SHOWING VARIOUS KINDS OF STRUCTURE. 

See text for explanation of numbers. Position of crystal faces shown: b, <010>, clinopinacoid; 

m, <110>, unit prism. *, percussion figure, vertical line parallel to clinopinacoid.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE Vlt

T

A. MICA HEAVILY "SPECKED" WITH MAGNETITE.

!K\*4fJ»V*'.X.-.'''-v*'-- ">''-.

 >IL *.y,~*. >- » v"v- »»

B. MICA SLIGHTLY "SPECKED" WITH MAGNETITE.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE VIII

A. SHEET OF MICA CONTAINING INCLUSIONS RESEMBLING 

ANCIENT HIEROGLYPHICS.

B. SHEET OF MICA INCLOSING TWO FLATTENED GARNET 

CRYSTALS. .

C. SHEET OF BIOTITE FROM MITCHELL COUNTY, N. C., INCLOSING 

A RHOMBIC CRYSTAL OF MUSCOVITE, BOTH HAVING THE SAME 

CLEAVAGE PLANES.
MINERALOGY. 19 

MICA MINING. 

HISTORY.

The ancient Romans are said to have spread a micaceous sand or 

a disintegrated mica schist over the arena of the Circus Maximus as 

a decorative material. In.India mica has been mined for centuries 

and was long used in lanterns, for decorative effects, and as a medicine. European countries have used mica for glazing windows for 

.two or three centuries. The aborigines of North America mined 

mica extensively in the Southern Appalachian States, and it appears 

to have been used by the mound builders of the Mississippi Valley 

region for ornamental purposes.

Mica mining in the United States began with the opening of the 

Ruggles mine, in Grafton County, N. H., about 1803. Other mines 

afterwards opened in the same State furnished practically all the 

mica used in the United States until after the middle of the nineteenth century. Mining in New Hampshire was carried on in a desultory way until about 1840, and then more extensively until after 

1860. Some of the deposits in Pennsylvania were probably tested 

shortly after the middle of the century, but definite evidence regarding this can not be obtained.

Mica mining was started on a large scale in North Carolina soon 

after 1868, and mining in New Hamshire then declined. For many 

years North Carolina has been the principal producer of mica in 

the United States. Extensive mica mining has also been carried 

on intermittently in several other States during the last 40 years,, 

especially in Virginia, South Dakota, New Mexico, and Idaho. No 

records were kept of the quantity and value of the mica mined in 

the United States until 1880, and since that time the output hasvaried considerabty, partly because of variations in business condition but since 1885 chiefly because of competition with imported mica.. 

Prior to 1890 the bulk of the mica mined was used in the glazing 

trade, for which only large sizes were considered suitable. Sincethen, owing to the great growth in the manufacture of electrical 

apparatus and machinery, an increasing quantity of mica has been 

used and smaller patterns have been employed in the glazing trade. 

During the same period ground mica for wall-paper decoration has* 

utilized much of what had formerly been waste material.

Through 1880 and during a few following years the. great demand 

for large sheet mica was supplied chiefly by the domestic production.. 

After 1885 increased imports of mica from India made inroads, on 

the domestic production, and this competition still continues. In 

1890 an ad valorem duty of 35 per cent was placed on imported 

mica. The tendency of this duty was to prohibit imports of mica
20 MICA DEPOSITS OF THE UNITED STATES.

with large bulk and small value, such as small sheet mica and the 

material then classed as scrap. In 1897 the tariff was changed to> 

6 cents per pound for unmanufactured mica and 12 cents per pound 

for cut or trimmed mica, with an additional 20 per cent ad valorem 

for each. These rates of duty practically made the importation of 

small sheet and scrap mica impossible, and to meet the growing demand for those sizes domestic mica mining was greatly stimulated. 

The tariff was changed again in 1909 to 5 and 10 cents per pound for 

unmanufactured and cut or trimmed mica, respectively, with 20 per. 

cent ad valorem, without apparent effect on the mining industry. The 

tariff of October 3,1913, provides for the following duties: Unmanufactured mica valued at not above 15 cents per pound, 25 per cent ad 

valorem; cut mica, mica splittings, built-up mica, and all manufactures of mica, 30 per cent ad valorem; ground mica, 15 per cent ad 

valorem.

METHODS.

The occurrence of mica in irregular deposits makes the method of 

mining it problematic. At a few deposits the pegmatite is in sheetlike bodies that are not badly warped and are persistent for some 

distance. If the mica content is not extremely variable such deposits 

can be easily mined by ordinary methods that is, by regular shafts, 

adits or tunnels, drifts, and stopes; if the mica content varies greatly 

stopes and other workings will be less regular. If the pegmatite forks, 

rolls, is folded, pinches, or bulges out into large masses, the method 

of mining generally employed is called " groundhogging " or "gophering." in which the workings are very irregular, and waste rock is left 

to accumulate because it is difficult to remove through the small tunnels and openings.

If the pegmatite occurs in large masses rich enough to be worked 

for mica regular quarry methods may be used. In the New England 

mica mines the ore and the waste rock are removed by open quarrying, with derricks and inclined tracks.

Much mica is mined each year in the United States from deposits 

operated in a small way, without steam engines, pumps, or power 

drills. Hand power or, at most, horsepower is used in such places to 

hoist mica, waste, and water from the workings, and drilling is dono 

by hand. Tracks with mine cars may or may not be used.

As a general rule it is best to open a mica prospect by cuts, shafts, 

or tunnels in the pegmatite along the streak or deposit of mica and 

also at other places that appear favorable until it has been determined that mica is present in paying quantities. Then only is it 

safe to develop by vertical shafts to one side of the vein or by long 

crosscut tunnels from lower levels on a hillside. Few prospects
MICA MINING. 21

give evidence on the surface that they will warrant extensive development or large outlay in mining equipment.

In mining care is necessary to avoid drilling through good crystals 

of mica. Miners using either hand or power drills can generally 

tell by its clogging when the drill is in mica. Only small charges 

of dynamite should be used in blasting around a pocket of mica, 

and black powder is even better, if it can be used.

In some regions, especially in the mountains of the South, work 

at some of the mines is not carried on systematically nor with proper 

equipment. Timbering is very sparingly used, and pillars are left 

only where they are absolutely needed to keep the mine open for the 

time being. In decomposed formations this type of " ground-hog " 

working soon becomes dangerous and remains a menace to future development, yet some mines can be worked only by such methods. 

The deposits may not be rich enough to warrant the expense necessary to equip the mine with proper machinery and timber it carefully and may pay only "good wages" to the lessees^

In some of the mountain regions the mica is found in rather inaccessible places, and all tools and provisions intended for the 

mines are packed on animals or even on men's shoulders. The mica 

is carried away by the same method.

Few companies apparently keep records of the yield of mica obtained per ton of rock mined. The deposits vary so greatly in their 

content of mica that this information does not seem to be of much 

help to the individual producer, yet such information from many 

mines, if brought together, would be useful. A yield of 5 to 10 per 

cent of sheet mica from all the pegmatite mined is considered very 

good, if the sheets average at least 3 inches square. Few mines will 

yield over 10 per cent of sheet mica.

PREPARATION OF MICA FOB THE MARKET.

Mica as it is obtained from the mine consists of rough crystals 

and blocks ranging in diameter from an inch or less to several feet. 

Before the mica is ready for the trade these crystals have to be 

cobbed, split, rough trimmed, sorted, cut into patterns, built up 

into large composite sheets, or ground. In many places these operations are carried out in two or three different plants, owned by as 

many companies, but some of the better-equipped companies prepare 

the mica in one plant, built either at the mine or near by.

The rough mica crystals are cobbed and cleaned of adhering

quartz, feldspar, or dirt by rapping with hammers. They are then

split with wedges or splitting knives into plates one-sixteenth of an

inch or less thick. The rough edges are cut off these plates by

111375 23 3
22 MICA DEPOSITS OF THE UNITED STATES.

knives held at a low angle to the cleavage, and the mica is graded 

for size and quality. Large quantities are sold in this rough shape, 

being packed into boxes and graded so that all the mica in a particular box is guaranteed to trim into sheets containing a prescribed 

number of square inches. Small sheets may be left with rough 

edges and used for punching into mica disks, washers, and other 

forms. After being graded the mica is ready for further splitting 

and trimming into the forms and patterns desired by the trade. It 

is trimmed with large shears and punches, operated either by hand 

or by power. If shears are used the mica is cut into the desired 

form around a templet of wood, metal, or other material laid against 

it. Mica-punching machines are equipped with dies to punch disks, 

washers, and all forms of patterns.

The introduction of mica board or built-up mica for electrical 

manufacture has developed a large demand for " thin splittings." 

Most, of these are made from mica sheets less than 4 inches in 

diameter. In making "thin splittings" the edges of the plates are 

first ground on a bevel and then pressed against a flat surface to 

open the cleavages. The mica is then "thin split" by thin-bladed 

knives into sheets ranging from one eight-hundredth to one twelvehundredth of an inch thick, and lots have been received from India 

averaging in thickness about one sixteen-hundredth of an inch. In 

the United States "thin splitting" is generally done by girls as 

piecework.

The " thin splittings " are built up into mica board, flexible mica 

sheets, and tape. Mica board is built up either with or without 

tissue paper from several layers of "thin splittings" coated with 

shellac. It is then made up into sheets measuring 2 by 3 feet and 

subjected to baking under hydraulic pressure. The required thickness is obtained afterward by sanding and milling machines. Mica 

board can be exit or punched and treated like sheet mica. When 

heated it can be bent or rolled into tubes and molded into collars or 

other forms. If the mica board is to be subjected to a high temperature a siliceous binder is used instead of shellac. Cloth or paper 

sheets built up with flexible cement and thin splittings are much 

used, flexible tape being made from these sheets by cutting them 

into strips. '/ '" ' 

The rough, small mica and the waste from trimming sheet mica 

are ground. Two processes, wet grinding and dry grinding, are 

employed according to the uses to which the ground product is to be 

put. A. S. Watts's description 13 of a wet-grinding process used in 

the mountains of the South is quoted below:

13 Mining and treatment of feldspar and kaolin in the southern Appalachian region : 

U. S. Bur. Mines Bull. 53, pp. 86-87, 1913.
MICA MINING. 23

The method of grinding mica is unique, since the process is shredding ra'Jier 

than abrasion. The process in detail is as follows: The coarse mica is washed 

by passing it through a revolving cylindrical screen upon which water plays 

and thus any fine sand is washed away. The washed mica scrap collects in a 

tank of water and any refuse that floats is carried off by the water which constantly overflows the tank.

The mica-grinding mill.into which the mica next goes is a cylindrical wooden 

vat 3 feet high and approximately 3 feet in diameter, with a wall 6 to 8 inches 

thick, built of wooden blocks set with the end of the grain toward the. inside 

to present a wearing surface. The grinder is a wooden wheel about 6 inches 

thick that fits loosely inside the vat. This wheel is built of ordinary plank 

cut to present as much end grain as possible and spiked together to give the 

desired thickness. It is attached to a heavy vertical shaft in the center of 

the vat and is rapidly revolved by steam or water power. The pressure of 

the wheel on the material in the vat is maintained by a pressure spring from 

above.

The operation consists of charging the mill with washed scrap mica and 

adding just enough water to provide the desired lubrication. The wheel is then 

started and pressed down until it takes a firm hold upon the mica. The friction 

of the wheel against the mica scrap causes the sheets of mica to be forced between the laminae of adjoining sheets and thus the large blocks and sheets are 

gradually torn to pieces and reduced to the pulverized mica of commerce. After 

8 to 10 hours the mill is emptied, and by a flotation system similar to that used 

for removing mica from kaolin the fine mica is separated. The coarse mica 

is returned to the mill and the fine mica is allowed to settle and the water 

drawn off. The mica is then removed to drying tables where iris spread to 

dry. After drying it is placed in regular bolting machines similar to those used 

for bolting flour; the last trace of coarse material is removed and returned to 

the grinding mill. One such grinding mill will produce from 250 to 400 pounds 

of 160-mesh mica per day, hence many mills are necessary for a large output.

Some of the locally constructed Avet-grinding mills are built like 

large Chilean mills, but all of the working parts are made of wood ' 

that is, the tub lining and the rolls.

In dry grinding the Raymond pulverizer or a similar machine is 

generally used. In these machines the mica is crushed by suspended 

rolls revolving at high speed against a ring in a closed chamber. 

The ground product is conveyed by air draft to bolters for sizing. 

One No. 0 Raymond pulverizer will supply two Barnard & Leas bolting machines.

USES.

Mica is generally classed as one of the less useful nonmetallic 

minerals, but it is really very Useful in the electrical manufacturing 

industry, where it fills a need not supplied by any other substance, 

and it is of value in the glazing and decorative trades and in the 

manufacture of lubricants.

Mica was probably used in ancient times for decoration, but in 

modern times, before the present " electrical age," it was used chiefly 

for glazing, for which only clear sheets with perfect cleavage are 

suitable. It was first used in this way in lanterns and windows, but
24 MICA DEPOSITS OF THE UNITED STATES.

iater it was used in large quantities in stove windows and doors, for 

which its resistence to heat made it especially desirable. Much is 

still used in this way, though probably more is now needed for gaslamp chimneys and lamp shades. It also serves as a substitute for 

glass in picture frames. Before the method of annealing glass was 

developed mica was used in the portholes of battleships, because the 

glass manufactured in the early part of the last century would be 

shattered by the concussion of the cannon firing. Some mica was 

used in making spectacles for stone carvers, metal workers, and men 

around furnaces and smelters. The mica furnished a transparent 

medium of protection to the eyes and was not liable to be fractured 

by small chips of flying stone or metal.

Recently mica has been used in making lantern slides. 14 The slides 

have been prepared by George Palmer, of London, who used a special 

process to protect the mica from scratching. Lantern-slide "cover 

glasses" are also similarly prepared, and their use greatly reduces 

the weight of the slide.

A large quantity of mica is used to make disks for the vibrating 

membranes of phonographs and telephones. Only mica with the 

smoothest cleavage and of the highest perfection is suitable for this 

purpose.

Large quantities of mica split into thin sheets ("thin splittings") 

are used in the manufacture of ''mica board" or built-up mica. 

This product is applicable to many uses in electrical manufacture, 

for which natural sheets of mica sufficiently large are costly and difficult to obtain.

In the manufacture of electrical apparatus and machinery mica 

is used in sheets of various sizes and shapes, including washers and 

disks, at places in which a noninflammable insulating material is 

necessary. Thus, properly trimmed sheets are used between the 

commutator segments of motors and dynamos, for tubes, sheets, and 

other forms in transformers, and for washers and rings around many 

bolts and screws requiring insulation. Large disks and washers are 

used in every arc light and smaller ones in the sockets of incandescent 

lamps. Flexible mica-covered cloths and tape find varied uses in 

many pieces of electrical apparatus. The domestic mica is satisfactory for all insulation except for commutators of direct-current 

motors and for dynamos built up of bars of copper and strips of 

mica. For this purpose no mica is as satisfactory as the phlogopito 

or " amber " mica. This mica is of about the same hardness as the 

copper of the commutator segments, and therefore wears down evenly 

without causing the motor to spark.

Ground mica is used in largely increasing quantities for the decoration of wall paper, for the manufacture of lubricants, fancy paints,

14 British Jour. Photography, June 16, 1916, p. 350.
MICA any ING. 25

rubber goods, molded mica, and roofing papers, and as covering for 

steam pipes. Finely ground mica is applied to Avail paper to furnish 

luster and brightness. For this purpose wet-ground mica is the most 

satisfactory, because, it is claimed, the scales are cleaner and flatter 

than in the dry-ground product. Ground mica mixed with oil forms a 

good lubricant for axles and other bearings, and quantities are used 

for this purpose. For fancy and brocade paints ground mica is 

mixed with various pigments and serves the purpose of metallic paint. 

Many rubber goods contain finely ground mica used both as an 

adulterant and to furnish certain qualities desired in the rubber. 

Ground mica mixed with shellac or plaster is used in the form of 

" molded mica " for insulation of trolley wire and for similar supports. Tar and other roofing papers are coated with coarse flakes 

of " bran " mica to prevent sticking when they are rolled for shipment. Bran mica and coarser grades mixed with other materials 

furnish good fireproof and heat-retaining coverings for steam pipes 

and boilers. The value of mica packing for steam pipes and boilers 

has been shown by experiments.15 R. Atkinson, mechanical superintendent of the Canadian Pacific Railway, found that the loss of 

heat resulting from the use of several different kinds of packing 

material around a 14-inch cube tank in which water had been brought 

to boiling and then allowed to cool was as follows:

Loss of heat in, boiler packed with different lieat-retaining materials.

Material.'

Magnesia blocks. ................................................................

Loss in 

5 hours 

(°F.).

84

53

m

332

30

20

Temperature at end 

of 5 hours 

(°F).

128

159

17Si

178}

182

192

In experiments made by the Grand Trunk Eailway on five locomotives protected ,by different materials, mica covering saved about 

02 per cent of the heat radiated from a bare boiler and was about 

twice as efficient as sectional magnesia block covering.

Rather coarsely ground or " bran " mica is used in the manufacture of concrete facing material to give the effect of a finish of 

natural rock. This material is prepared in different ways, and various mixtures of other minerals, such as biotite, tourmaline, and hornblende, are used to heighten the effect.

Within the last few years a new mica product called " tung ash," 

has been placed on the market. The material is bronze-colored and

15 Mica insulation for steam pipes and boilers : Engineering, London, Feb. 22, 1901.
26 MICA DEPOSITS OF THE UNITED STATES.

is obtained by calcining a hydrated biotite mica found 5 miles southeast of Hecla, in the Turret Mountain mining district, Chaffee 

County, Colo. The mica as mined comes in rather dull brownishblack crystals or plates, which are flexible but inelastic. When 

heated these crystals expand or exfoliate greatly, and the mica assumes various tints of bronze with metallic luster. Tuno; ash should o

find a place for decorative uses.

GRADES.

Mica is graded differently by the different trades using it. The 

manufacturers using rough sheet mica grade it according to size 

as extra special, special, Nos. 1,2, 3, 4, 5,6, and punch. Extra special 

is rough sheet mica that will cut into sheets containing more than 

48 square inches. No. 1 wiUtrim into sheets containing 24 to 36 

square inches. No. 6 includes mica from punch size to material 

that will cut sheets containing 3 square inches. Punch mica will 

yield disks 1-| inches in diameter. All mica too small for punching 

is sold as scrap for grinding.

Good, clear, light-colored sheet mica, with smooth cleavage, is 

sold as "stove" mica. Strongly colored, discolored, stained, and 

the rougher grades of mica are classed as "electric." Some of the 

finest stove mica is used in electrical manufacture. Stove mica 

is graded as A No. 1, No. 1. A No. 2, and No. 2, according to quality. 

A No. 1 is the best quality.

PRODUCTION AND IMPORTS.

Mica is of widespread occurrence in the United States. Deposits 

of commercial value or of promise have been found in 20 or more 

States. Large productions have been reported from North Carolina, 

South Dakota, New Hampshire, New Mexico, Idaho, Virginia, Colorado, South Carolina, Alabama, and Georgia. Other States in 

which mica deposits have been found are Maine, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Maryland, Wyoming, Montana, Texas, Arizona, Utah. 

Nevada, and California. The distribution in the different States 

will be treated in the description of the deposits in those States.

Mica deposits occur in many other countries and have been mined in 

several of them. The most productive are India, Canada, British 

East Africa Protectorate, and Brazil. Other countries that have contributed to the world's production or that may do so in the future are 

South Africa, Ceylon, China, Japan, Argentina, Australia, New Zealand, Norway, and the Philippine Islands.
MICA MINING. 27

Only a few of the numerous varieties of mica have so far been 

used commercially, some of them because of their physical properties 

and others because they contain certain elements which can be profitably extracted from them, such as vanadium from roscoelite and 

lithium from lepidolite. This report considers only micas that are 

valuable because of their physical properties muscovite, phlogopite, 

and biotite. Of these varieties muscovite and a very little biotite 

have been mined in the United States, but no phlogopite deposits of 

commercial value have been found here, the supply of this variety 

coming principally from Canada, though a little is received from 

Ceylon.

Mica iiroduced in the United States, 1880-1921.

Year.

1880............................... ....... .

1881................ .............. ......

1882. ............................................

1883.............................................

1884.............................................

1885.................................. ... ......

1886.............................................

1887.............................................

1888.............................................

1889.............................................

1890.............................................

1891.............................................

1892.............................................

1893.............................................

1894. ................................ ..........

1895.............................................

1896. ................................ ..........

1897.............................................

1898. ............................................

1899.............................................

1900................................. ..........

1901.............................................

1902.............................................

1903.............................................

1904............................... . ..........

1905.............................................

1906. ............................................

1907.............................................

1908.............................................

1909.............................................

1910..............................................

1911................................ ....... .

1912............................... .........

1913................................ . .........

1914............................... ... ..

1915.............................................

1916.............................................

1917.............................................

1918.............................................

1919. . ...........................................

1920................................ . ..........

1921.............................................

Rough trimmed and 

cut mica.

Quantity.

Pounds. 

81,669 

100,000 

100, 000 

114,000 

147,410 

92,000 

40,000 

70,000 

48,000 

49,500 

60,000 

 75,000 

75,000 

51.111 

35^943 

81,408 

49, 156 

82,676 

' 129,520 

108,570 

456,283 

360,060 

373,266 

619,600 

668,358 

924, 875 

1,423,100 

1,060,182 

972,984 

1,809,582 

2.476,190 

1,887,201 

845,483 

1,700.677 

556.933 

553,821 

865,863 

1,276.533 

1,644.200 

1,545,709 

01,683.480 

741, 841

Value.

$127,825 

250.000 

250,000 

285,000 

368.525 

161,000 

70,000 

142,250 

70,000 

50,000 

75,000 

100,000 

100,000 

80,629 

43,793 

50,381 

65,441 

80,774 

103,534 

70,587 

92, 758 

98,859 

83,843 

118,088 

109,462 

160,732 

252,248 

349,311 

234,021 

234,482 

283,832 

310,254 

282, 823 

353,517 

278,540 

378, 259 

524,485 

753,874 

731,810 

483,567 

a 546, 972 

118,513

Scrap mica.

Quantity.

Short tons.

1,000 

2,000

196 

496

ise

191 

148 

222 

740 

3,999 

1,505 

5,497 

2,171 

1,400 

1,659 

1,096 

1,126 

1,489 

3,025 

2,417 

4,090 

4,065 

3,512 

3,226 

5,322 

3,730 

3,959 

4,433 

3,429 

2,292 

3,258 

5,723 

2, 577

Value.

si6,666

 : 15, 000

2,450 

6,200

8,300 

8,595 

5,450 

1,750 

14,452 

27,564 

30,878 

55, 202 

19,719 

35,000 

25,040 

10,854 

17, 856 

22,742 

42,800 

33,904 

46,047 

53,265 

45,550 

49,073 

82,543 

51,416 

50,510 

69,906 

52,908 

33, 130 

58,084 

167.017 

56,849

Tota 

value

8127, 

250, 

250, 

285, 

368, 

161, 

80, 

157, 

70, 

52, 

81, 

100, 

100, 

88, 

52, 

55, 

67, 

95, 

131, 

101, 

147, 

118, 

118, 

143, 

120. 

178, 

274, 

392, 

267, 

280, 

337, 

355, 

331, 

436, 

329, 

428, 

594, 

806, 

764, 

541, 

713, 

175,

a Uncut sheet mica onlv.
28 MICA DEPOSITS OF THE UNITED STATES.

Mica imported for consumption in the United, States. 1898-192J.

Year.

1898.

1899.

1900.

1901.

1902.

1903.

1904.

1905.

1906.

1907.

1908.

1909.

1910.

1911.

1912.

1913.

1914.

1915.

1916.

1917.

1918.

1919.

1920.

1921.

Sheet.

Unman u f actured .0

Quantity.

Pounds. 

877,930 

1,709,839 

1,892,000 

1,598,722 

2,149,557 

1,355,375 

1,085,343 

1,506,382 

2,984,719 

2,226,460 

497,332 

1.678,482 

1,424,618 

1,087,644 

1,900,500 

2,047,571 

360,888 

433,822 

703,832 

656,391 

741,429 

723. 713 

1, 298, 537 

328,444

Value.

$115,930 

233,446 

290. 872 

299,065 

419,362 

288,783 

241,051 

352,475 

983,981 

848,098 

224 456 

533,218 

460,694 

346,477 

649,236 

751, 092 

168,591 

240.449 

42i;856 

414,823 

658,576 

726,532 

1,177,943 

331, 219

Cut and splittings.*

Quantity.

Pounds. 

78,567 

67,293 

64,391 

78,843 

102,299 

67,680 

61,986 

88,188 

82.019 

112, 230 

51,041 

168,169 

536,905 

241, 124 

88,632

W (<0

C 

( c 

(c 

(c 

(c( c («

Value.

$34,152 

42,538 

28,688 

35,989 

46,970 

29,186 

22,663 

51,281 

58,627 

77.161 

41,602 

85,595 

263,831 

155,686 

99,737 

191,926 

456,805 

447,962 

646,080 

1,014,181 

880,906 

762,228 

2 011,434 

758,521

Ground.

Quantity.

Pounds.

(') 

( c) 

d 343, 824 

290.757 

404,848 

344,040 

362,000 

92,963 

11,587 

62

134,650

Value.

1,298 

3.389 

6,611 

4,765 

4,088 

3.858 

3,420 

1,044 

1,647 

9

2,166

Total.

Quantity.

Pou 

95 

1,77 

1,95 

1,67 

2,25 

1,42 

1,14 

1,59 

3,06( 

2,33 

54 

1.84){: (<

c 

c 

c 

c 

c 

(c 

(c 

(c(«

nds. 

8,497 

7,132 

6,391 

7,565 

1,856 

3.055 

7,329 

4,570 

5,738 

8,690 

8,373 

8,651 

)

)

Value.

$150,082 

275,984 

319, 560 

335,054 

466,332 

317,969 

263,714 

403,756 

1,042,608 

925,259 

266,058 

618,813 

725,823 

505,552 

755,584 

947.783 

629,484 

692,269 

1,071,356 

1,430.04& 

1,541 129 

1,488,769 

3,189,377 

1,091,906

o Essentially trimmed sheets.

6 Includes the Madras square-shaped uncut sheets.

«Quantity not reported.

<* Figures for quantity cover only last six months of 1912.

DESCRIPTION OF MINES.

ALABAMA. 

GENERAL FEATURES.

Some of the mica deposits in Alabama were worked by the aborigines, probably during the general prehistoric period in which mica 

was mined in North Carolina. These ancient workings are mentioned 

below in the descriptions of the Curley mine (p. 34), the Miller 

mine (p. 35), and mine No. 5 of the Great Southern Mica Co. (p. 32). 

The literature on the mica mines in Alabama is meager, and the 

details of the history of mining in the State are not easily learned. 

Residents of the mica region in Randolph County say that some of 

the mines there were worked about 1885. Other mines were opened 

in 1893,16 when the remains of older mines were found near them. 

Oak trees 12 to 15 inches in diameter were growing on the dumps 

of these older mines, which may have been worked by earlier white 

miners or by aborigines.

Considerable work was done from about 1898 to 1900 by Hugh 

Mclndoe around Pinetuckey, in Randolph County. The next period

18 Eng. and Min. Jour., vol. 56, p. 145, 1893.
ALABAMA. 29

of activity in the same region extended from 1906 to 1908, when the 

Great Southern Mica Co. operated several mines. A few notes on 

this period have been given by W. F. Prouty " and H. D. McCaskey. 18 

Since the Great Southern Mica Co. ceased operations mica mining 

in Alabama has been very intermittent. The largest output made 

in the State in recent years has come from the vicinity of Pyritoii ; 

in Clay County.

Mica deposits have been found in rather widely scattered areas 

in central eastern Alabama. The most productive deposits are in 

Randolph, Clay, and Tallapoosa counties, but other deposits have 

been found in Lee and Coosa counties. Most of these counties are 

in the Piedmont Plateau, but the western part of Clay County is 

broken by small mountain ridges. Some of the deposits are in the 

rolling, less-dissected parts of the plateau at a distance from the 

rivers; others are in the river valleys, where the relief is considerable.

In Randolph County mica deposits have been opened in a belt extending from a point near the old Micaville post office, on the northcentral edge of the county, southward and south westward down 

nearly to the forks of Tallapoosa and Little Tallapoosa rivers and 

across Tallapoosa River toward Lineville. In Clay County the 

principal deposits are in Shinbone Ridge, northeast of Pyriton, but 

other deposits have been prospected near Flat Rock and 2 miles 

south of Lineville. Still others are reported to occur in the Wicker 

Beat lands, near the southern edge of the county. In Tallapoosa 

County several deposits that lie 5 to 6 miles northeast of Dadeville 

have been worked recently. In Lee County prospects have been 

opened near Opelika and near Auburn. In Coosa County a prospect was opened some years ago near Hissop. These deposits were 

visited by the writer in the autumn of 1914. Work was in progress 

only near Pyriton, and it consisted of a test run at the old M. & G. 

Co.'s mine and of prospecting by J. Warren May. The mines near 

Dadeville were temporarily closed.

The rocks in the mica region consist of gneisses and schists mapped 

as crystalline schists by E. A. Smith,10 and as distinct from certain 

other schists belonging to the Talladega formation (corresponding 

to the Ocoee of Arthur Keith), with which they are more or less 

associated. These crystalline schists are probably the same as the 

Carolina gneiss mapped by Keith in North Carolina. Large belts 

of these crystalline schists and parallel belts of the Talladega formation extend northeastward from the boundary of the coastal plain 

in Chilton, Elmore, Macon, and Russell counties across this part of 

Alabama into Georgia. The deposits in Lee and Tallapoosa coun-

" Mines and Minerals, vol. 28, p. 236, 1907.

18 Notes on some gold deposits of Alabama: U. S. Geol. Survey Bull. 340, p. 46, 1908.

18 Geological map of Alabama, Alabama Geol. Survey, 1894.
30 MICA DEPOSITS OF THE UNITED STATES.

ties are in the largest area of crystalline schists mapped by Smith, 

and those in Randolph, Clay, and Coosa counties are in another large 

belt of the same rock.

The occurrence of the mica-bearing pegmatites in Alabama is 

very similar to that in other States in the South. The pegmatites 

occur in sheets, lenticular bodies, and irregular masses of varying 

thickness and length. They cut the inclosing gneisses and schists 

both conformably with and across their foliation. Many of the 

deposits in the less-dissected parts of the plateau have been affected 

by the general weathering of the rocks of the Piedmont Plateau, 

and their feldspathic contents are kaolinized to depths of 20 to 50 

feet or more. Others in the deeper valleys below the plateau levels 

contain hard unaltered rock close to the surface.

The sheet mica from most of the deposits in Randolph and Clay 

counties has a clear rum color and good cleavage. Some of the 

deposits yield a large proportion of scrap mica, but most of the 

sheet mica is suitable for use in stoves. The deposits of Tallapoosa 

and Lee counties yield a slightly cloudy to specked mica, which is 

suitable chiefly for use in electrical work.

COOSA COUNTY. 

JOHN H. THOMAS PROSPECT.

A prospect was opened for mica several years ago on the John H. 

Thomas place, 1 mile northeast of Hissop, or 10 miles southwest of 

Kellyton. The work done consisted of a small open cut and a short 

tunnel (now caved in) in a hillside. The country rock is biotite 

granite gneiss. Fishbone and A mica were left around the prospect, 

but sheet mica and a few beryl crystals were reported to have been 

found. Potash feldspar and massive quartz were the gangue minerals removed.

RANDOLPH COUNTY. 

MINES OF THE GREAT SOUTHERN MICA CO.

A group of mica deposits were prospected and worked in Randolph 

 County from about 1906 to 1908 by the Great Southern Mica Co. 

This compan}7^, after making preparations for extensive operations, 

moved to Asheville, N. C. A trimming plant and grinding mill 

were erected at Heflin, the railroad shipping point, about 20 miles 

north of the mines. Four or five deposits were opened in the Pine 

Tuckey region, and others were prospected several miles to the 

southwest, on the west side of Tallapoosa River. The company 

operated energetically for awhile, but was handicapped by much 

dead work in some of the places opened, by long hauls over poor roads 

:to the railroad, and by a failure to find sufficient mica to keep the
ALABAMA. 31

5h3ft reported mor<s 

n IOO Feet deep

Dump

large 'equipment going. Only part of the workings of this company 

were visited and these were in bad repair.

Mine No. 1. Mine No. 1 of the Great Southern Mica Co. is 3-£ 

miles S. 25° E. of Pinetuckey in a westward-sloping hillside. It was 

worked by open cuts and shafts with tunnels and drifts running

 .northeastward. The workings were in bad repair when examined,

 but consisted of a shaft 40 feet deep to water and reported to be 

more than 100 feet deep, at the northeast end of the workings, and 

two other shafts open to depths of 30 feet, which were sunk on the 

'" vein'' to the southwest. The position of the different workings is 

^shown in figure 2.

The country rock is garnetiferous and kyanitic mica gneiss, which 

'strikes northeast and dips southeast. The pegmatite is nearly conformable with the H

 i i i 11 A DfJfDP .gneiss but locally A 

cuts across its bedding. It varies in 

thickness from 18 

inches at the southwest end of the 

workings to more 

than 8 feet near the Dump-'?^, 

middle and to at "'^\ 

least 5 feet at the 

Jiortheast end. where Pegmatite pinch

 A. P -t-i ,1 i . to /8 inches . 

its lUll thlCkneSS IS . o 25 so_____.ooFaot

llOt exposed. The M^No pegmatite

IP, j i FIGURE 2. Plan of Mine No. 1 of Great Southern Mica Co.,

snaitS ana WOrKingS 33 mncs- St 25° E. of Pinetuckey,, Randolph County, Ala.

were sunk on an incline running about 70° SE., which probably represents the dip of 

the pegmatite. The "vein" either forks or is folded over to the 

southeast near the northeast end of the workings, where the open cut 

is widest. The formation is semidecomposed near the surface, but 

:20 feet below it is fairly fresh and hard.

The feldspar is at least in part of the potash variety, but it does 

not occur in large masses. Quartz is not especially prominent. 

Other minerals observed were biotite in plates 2 inches or less in di- 

.ameter, bluish-green apatite, pink garnet, and black tourmaline. The 

muscovite mica is of fine quality and has a clear light rum color and 

excellent cleavage. Nothing could be learned of the quantity of 

mica the mine yielded.

Mine No. 2. Mine No. 2 of the Great Southern Mica Co. is 3 miles 

S. 28° E. of Pinetuckey, in the west brow of a hill. Two shafts were 

sunk, one vertical and about 30 feet deep and the other 35 feet to the 

northwest on an incline of about 30° toward the first shaft. Pesrma-
32 MICA DEPOSITS OF THE UNITED STATESApproximate scale

lop 200 300 Feet

tite was followed in both shafts, but the relations to the kyanite mica 

gneiss could not be learned, as the shafts had caved badly. The principal vein mineral removed was semidecomposed potash feldspar. 

A little biotite was found and a few grains of pyrite were seen in the 

rock on the dump. Only small plates of mica had been left aroundr. 

but these were of clear light rum color. This deposit probably did 

not yield much mica, for little work was done.

Mine No. 5. Mine No. 5 of the Great Southern Mica Co. is 2 miles-- 

N. 35° E. of Pinetuckey. Here the aborigines dug a large irregularshaped pit or open cut more than 60 feet across and 5 to 12 feet deepr 

around the mouth of which they piled the waste rock. The company

has sunk numerous; 

shafts with tunnels,, 

open cuts, trenches., 

and pits, as shown in. 

figure 3. The workings have caved so* 

badly that the formations could not bestudied in detail.

The country rockis mica gneiss, kyanitic and h i gh 1 y 

garnetiferous in 

places, and the dip> 

and strike differ at 

different openings.. 

The strike varies; 

from east to west 

and ranges from 

N. 60° W. to N. 40°' 

E., and the clip is 

southerly. Evidently a large deposit of 

pegmatite was encountered in the ancient workings and in the deeper 

recent workings. (See 1 to 4, fig. 3.) This deposit has an easterly 

strike, and the north wall of garnet gneiss is apparently conformable 

with it. The pegmatite apparently pinches out toward the west, but 

gneiss was found in the crosscut trench. (See 7, fig. 3.) In the 

incline shaft (see 9, fig. 3) a pegmatite vein 10 feet thick, conformably inclosed in the gneiss, was tested. The formations at this place 

strike N. 40° E. and dip 60° SE. Pegmatite was also found in 

other workings (see 8, 10, 11, 12, and 14, fig. 3), but it seemed to be 

in disconnected masses.

j C5 Open cut 

 a Shaft

/*. Strike and dip of strata 60°

FIGURE 3. Plan of Mine No. 5 of Great Southern Mica Co., 

2 miles N. 35° E. of Pinetuckey, Randolph County, Ala. 

1, Shaft 50 feet deep in ancient open cut; 2 and 3, cavein of underground work between 1 and 4; 4, shaft 30 feet 

deep in ancient dump; 6, pit in ancient dump; 7, crosscut 

trench; 8, small pit; 9, inclined shaft, at least 30 feet 

deep; 10, incline about 20 feet deep; 11, shaft filled 

within 15 feet of the surface; 12, two shafts filled within 

20 feet of the surface, water in one; 13, open cut in 

ancient dump; 14, shaft 18 feet deep.
ALABAMA. 33

The formations are decomposed to depths of 20 to 25 feet, below 

which the pegmatite is hard. This depth was probably the limit 

to which the aborigines could work. Besides quartz and feldspar 

the most abundant minerals associated with the mica are biotite 

and black tourmaline. The mica is of very fine quality and has a

 clear light rum color and smooth, flat cleavage.

HUGH McINDOE MINES.

Several deposits were prospected or worked by Hugh Mclndoe, of 

Joplin, Mo., from 1898 to 1900. The principal one is a quarter of a 

mile west of Pinetuckey. Other prospects are about 2 miles N. 40° 

E. of Pinetuckey, or 300 yards S. 60° E. and 500 yards south of east, 

respectively, of mine No. 5 of the Great Southern, Mica Co'.

At the mine near Pinetuckey two shafts (one at least 50 feet deep), 

several pits, drifts, and inclines were made. The principal inclines

 extend from the surface east and south into the shafts. As the inclines had caved in it was not possible to reach the deep workings.

The country rock is mica gneiss, which strikes northeast and dips 

20° SE. where measured at two places in the incline from the west. 

Several bodies of pegmatite were cut in the workings and all were 

approximately conformable Avith the inclosing gneiss. The exposures of the pegmatite in the workings still open ranged from less 

than a foot to several feet in thickness. The mica obtained was of 

fine quality and had a clear light rum color and good cleavage. Mr. 

Charles Liner, who worked in the mine, states that the veins yielded 

^well.

At the prospect 300 yards southeast of mine No. 5 an irregular open 

cut 15 feet deep and about 25 feet long was made in a northeasterly

 direction and an arm was carried from it southeastward about 15 

i'eet. A 35-foot shaft was sunk 15 feet southeast of the open cut. 

About 30 feet northeast of the open cut is an ancient pit.

The country rock is garnet gneiss, which strikes N. 45° E. and dips 

50° SE. It incloses, almost conformably, beds of pegmatite, one of 

which was worked in the northeast part of the arm run from the open 

cut and another in its southeast part. This second bed of pegmatite is 10 feet thick and is probably the one encountered in the shaft 

to the southeast. Smaller streaks of pegmatite fork from the larger 

ones.

Several prospective pits have been opened about 300 yards east 

of this open cut, but little could be seen of the formations encountered. The country rock around these prospects is also garnet 

gneiss. The mica found in all the above prospects has a clear lightrum color and flat cleavage. Only small crystals had been left exposed in the workings or on the dumps.
34 MICA DEPOSITS OF THE UNITED STATES.

CURLEY MINE.

The Curley inane is If miles north by east of Pinetuckey. Remnants of ancient pits and dumps were found near the modern workings made by Horner & Phillips. The workings consist of a goodsized open cut and several pits and shafts. A 50-foot shaft 75 feet 

southeast of the main workings and a 25-foot tunnel to the north 

failed to cut the pegmatite.

The country rock is garnet gneiss, which strikes N. 70° E. and 

dips 45° SE. The pegmatite is about conformable with the bedding 

of the inclosed gneiss. Only a few feet of the pegmatite is inclosed 

but it is probably 8 to 10 feet thick. A cross section of the part exposed in the east end of the open cut shows the following from south 

to north. A 2-foot vein of quartz along the south wall, 2 to 3 feet 

of kaolinized feldspar carrying mica, and a 3-foot streak of massive 

mica composed of A, wedge, and fishbone crystals 1 inch to 4 inches 

across with intermixed quartz. A streak of quartz is inclosed in the 

middle of the pegmatite in the west end of the cut.

From an examination of the dumps it is evident that some goodT 

clear, light-colored mica with smooth cleavage was obtained. Weathered sheets of such mica 4 to 5 inches across were seen. The massive or solid mica is suitable for grinding, but the ground product 

could not be marketed until transportation facilities are improved.

PHILLIPS MINE.

The Phillips mine is half a mile southwest of the old Micaville 

post office and 2-| miles north of Pinetuckey. A dozen or more pits 

and open cuts and a shaft 50 feet deep were made in an area 20 yards 

wide by 120 yards long in a N. 30° W. direction. The deep shaft 

is a few feet north of an open cut at the southeast end of the area. 

This cut is 50 feet long by 6 to 18 feet wide and 2 to 10 feet deep, 

All the other workings are smaller.

The country rock is kyanitic and garnetiferous mica gneiss, which 

strikes east and dips 30° S. as measured in one of the prospects. 

About 200 yards north of the mine the gneiss strikes N. 10° W. and 

dips 35° W., which corresponds more nearly with the strike of the 

pegmatite in the mine workings. Both the gneiss and the pegmatite are decomposed and, as shown by the deep shaft, this decomposition extends as deep as 50 feet in places. Masses of quartz, some of 

them as much as 6 feet thick, were encountered in the workings. 

Mica occurs in large masses or bunches of A, wedge, and small 

ruled crystals along the bodies of quartz. One of these masses exposed is 10 feet thick. They contain variable quantities of quartz 

and some kaolinized feldspar but will probably average 75 per cent
ALABAMA. 35

mica. This material would be suitable only for grinding as scrap 

mica, and if the deposit were near the railroad it could be worked 

profitably for that purpose. The largest sheet mica seen would 

be suitable only for punching. Mr. Charles Liner states that goodsized sheet mica was obtained during mining. The dumps contain 

a number of tons of scrap mica that could be screened out if better 

transportation facilities were available.

Another prospect was opened 120 yards S. 20° W. of the shaft. 

Pegmatite containing small crystals of mica was exposed in this 

prospect.

MILLER MINES.

Several deposits have been tested or worked on the Miller place, 

2-| miles north by west of Pinetuckey. One of these deposits was 

worked by the aborigines, though remains of more recent work is 

seen around it. The ancient work consists of-an open cut 75 feet longin a northeasterly direction, 40 feet wide, and 10 feet deep, with 8 

feet of waste reported, in the bottom. The dumps are piled around 

the edge of the cut, and trees of considerable age are growing in 

them. In one place an oak tree 24 feet thick is rooted in the dump. 

Recent prospects consist of a shaft 45 feet deep in the cut with a drift 

to the southeast and a pit opened in the southeastern side near the 

middle of the cut. These workings encountered pegmatite but failed 

to disclose an}^ considerable body of mica.

An open cut 20 feet across and 5 to 10 feet deep, which was opened 

about 75 feet northeast of the ancient work, exposed pegmatite that 

looked promising. Another prospect pit 12 feet deep was opened 

100 feet east of the ancient cut. Kaolin and small mica were found 

at this place.

In a wooded flat or valley bottom about a quarter of a mile southwest of the large ancient working there are several pits and shallow 

shafts. An exposure of garnet gneiss with interbedded pegmatite in 

a pit on the southwest side of the workings strikes 1ST. 30° E. and dips 

25° SE. The formations exposed in the other openings appeared to 

lie nearly flat, showing only gentle low folds. In these shallow 

workings the feldspar of the pegmatite is mostly kaolinized. 

Weathered crystals of mica 6 inches across were left on the dumps 

after the last work.

The mica from the openings on the Miller place is all of good 

quality and has a clear light rum color and flat cleavage.

KNUTT MINE.

The Knutt mine is about 1£ miles north of Pinetuckey. The 

workings consist of an open cut 30 feet long and a tunnel 30 feet long 

extending from it N. 70° E. A pit was made 35 feet east and a tun-
36 MICA DEPOSITS OF THE UNITED STATES.

nel was driven northwest from a point 100 feet east of the workings, 

but no vein material was found. Near the modern workings there 

are ancient pits and dumps covered with vegetation.

The country rock is mica gneiss and is in places garnetiferous. 

It incloses the pegmatite in approximate conformity with its bedding, 

both striking about N. 70° E. and dipping 45° SE. The pegmatite 

occurs in streaks 1 foot to 3 feet thick, which in places bulge out 

into thicker masses. Thin horses of wall rock are -inclosed in the 

thicker parts. Bunches or pockets of mica occur in the bulges of 

the pegmatite, especially the knarled masses of A, fishbone, and 

wedge mica crystals which the local miners call "horsetail" mica. 

Good sheet mica of clear light rum color was found in the larger 

beds of pegmatite.

CAMPBELL MINE.

The old Campbell mine, owned by Horner & Phillips, is about 

1| miles west by north of Pinetuckey. This mine was worked about 

1885 by several open cuts and pits and is reported to have yielded a 

quantity of good mica. A trimming plant was erected and 8 or 10 

people were employed in splitting and trimming the mica. The 

country rock is garnet gneiss, which strikes northeast and dips southeast. The pegmatite, which strikes N. 40° E. and dips 20° SE., 

is probably more than 12 feet thick. It incloses horses of garnet 

gneiss, one of which had been turned out of the usual parallel relation with the wall rock to a strike of N. 10° W. and a dip of 30° 

E. The mica is of fine quality and has smooth cleavage and a clear 

light rum color. Sheets 4 to 6 inches across were seen around the 

workings.

Other outcrops of pegmatite were observed to the southwest 

adjoining the old Knopf place.

KNOPF MINE.

Six prospects were examined on the old Knopf place, now belonging to Thomas Morrison and the Wills heirs, about 1£ miles west of 

Pinetuckey. The prospects are simply pits, most of them rather 

small, scattered over several acres. The country rock around the 

prospects is garnet gneiss and mica gneiss. The outcrops observed 

showed a northeasterly strike and a southeasterly dip. Most of the 

pegmatites opened are small, ranging in thickness from 1 foot to 2 

feet, but one deposit is 6 to 8 feet thick and outcrops for more than 

100 feet in a direction N. 10° W. All of the prospects yielded clear 

light rum-colored mica with good cleavage, but most of it was in 

small crystals. Mica crystals 5 and 6 inches across were observed 

in one of the prospects.
ALABAMA. 37 

C. H. BOYD PROSPECTS.

Several prospects were opened on the land of C. H. Boyd, 2| miles 

south of Pinetuckey. Most of these prospects are about half a 

mile northeast of Mr. Boyd's house; four are on one hill within a 

few hundred yards of each other, another is about 200 yards southeast and still another is about 400 yards southeast of this hill. The 

one last indicated was opened by a small cut 15 feet across and a 25- 

foot shaft a short distance to the south. Here a pegmatite vein about 

3 feet thick cuts the kyanitic mica gneiss country rock almost conformably with its bedding that is, it strikes N. 60° E. and dips 

40° SE.

At the other prospects still less work was done and at some of 

them only pits about 3 feet deep were dug. In the prospect 200 

yards southeast of the hill a promising show of mica, with crystals 

3 to 4 inches across, was found near the surface in a vein of pegmatite about 3 feet thick. This vein was cut off at a depth of about 8 

feet by a slickensided fault. In a prospect at the southwest foot 

of the hill a 15-foot shaft was sunk to a 3-foot vein of pegmatite 

cutting kyanitic mica gneiss. A considerable quantity of mica crystals 2 to 3 inches across was taken from this prospect. Among other 

minerals found were potash feldspar, bluish-black tourmaline, 

bluish-green apatite in elongated crystals, and pinkish garnets. The 

other prospects on this bill yielded similar tourmaline and apatite; 

one of them yielded gray potash feldspar that showed beautiful 

regular perthitic banding in nearly parallel layers.

From these prospects about 2,000 pounds of the best mica was 

shipped, leaving 5 or 6 tons of rough mica suitable for scrap and for 

trimming into sheets measuring 2 by 3 inches and punch sizes. The 

mica has been obtained from a point near the surface and part is 

clay-stained from surface weathering. The mica that is not so 

stained is of good qualitj' and has a clear light rum color and flat 

cleavage.

LANDERS & AYRES PROSPECT.

A prospect owned by G. V. Landers and J. D. Ayres, of Newell, 

Ala., was opened on the west side of the public road If miles south 

of Pinetuckey. The work consists of an open cut 60 feet long and 

2 to 10 feet deep, driven west into the hillside, and a pit about 100 feet 

to the south in another deposit of pegmatite. The country rock is 

mica gneiss, which strikes east by north and dips southward. .The 

pegmatite is approximately conformable with the gneiss. It is several feet thick and incloses a vein of massive quartz about 1 foot 

thick. The largest sheets, of mica seen were 3 to 4 inches across. 

Some of these had the A structure and some contained a few small 

specks. Most of the, flat sheets were clear and rum-colored. 

111375 23 1
38 MICA DEPOSITS OF THE UNITED STATES.

C. L. HOLMES PROSPECT.

Several small prospects have been opened on the land of C. L. 

Holmes, a little more than 4 miles south by east of Pinetuckey, 

southwest of the road leading to Rice Mill. The prospects are on 

the summit and the northeast side of a hill that rises about 200 feet 

above the valley that the road traverses. The country rock is 

kyanitic mica gneiss, which strikes N. 30° E. and has a nearly vertical dip. The pegmatite has decomposed badly and is heavily 

stained with iron oxide near the surface. Coarse, dark-red fractured garnets half an inch to 1£ inches in diameter were seen in 

one of the prospects. Some small mica that would yield material 

suitable for punching and some that would cut sheets 2 by 3 inches 

was taken out of the prospects. This mica has a clear rum color 

and a smooth flat cleavage, but much of it is clay-stained from the 

surface weathering of the inclosing pegmatite.

Mica prospects are reported to have been opened on the land of 

S. A. Creed, about half a mile southeast of the Holmes prospects.

MINES OF RANDOLPH MICA CO.

The Randolph Mica Co. owns three mines near Mclnnish Ferry, 

10 to 11 miles N. 70° E. of Lineville on the east side of Tallapoosa 

River, and 7^ miles S. 17° W. of Pinetuckey. Douglas Smith, of 

Wedowee, and Dallas Smith, of Opelika, represent the company and 

operate the mines. The last work was done in June, 1914. The only 

working examined is on the road about a quarter of a mile northeast 

of Mclnnish Ferry. The other workings are reported to be larger 

than this, but no guide was available to show them. The company 

has a plant equipped with punches and trimming shears near one of 

the other workings. The working examined consists of an open cut 

40 feet long, 10 to 12 feet wide, and 15 feet deep driven N. 40° E. 

through the roadway into a hillside. ,The cut was later bridged over 

for the road.

The country rock is kyanite gneiss, which strikes northeast and 

dips southeast. The relation of the pegmatite to the gneiss is variable. The pegmatite appears to be a blanket ledge, which strikes N. 

50° W. and dips 25° SW., outcropping on the hillside below the road. 

A fork or prong of the pegmatite 3 feet thick cuts through the gneiss 

vertically to the surface and in mining was followed into the larger 

underlying mass. The pegmatite includes segregations of quartz, 

one of which measures 6 feet across. The feldspar is fresh and hard 

and the crystals of mica are clean and free from clay stains. The 

largest crystals seen in the pegmatite were 3 to 4 inches across, but 

sheets 8 by 10 inches are reported to have been obtained from the 

best of them. Plates of mica shown to the writer by Mr. Dallas
ALABAMA. 39

Smith, at Opelika, were several inches across and of the same fine 

quality as the small crystals at the mine that is, clear light rumcolored, and having a smooth, flat cleavage.

WILLIAM FOSTER PROSPECT.

The William Foster prospect is 11 miles N. 55° E. of Lineville, 

west of Tallapoosa River. It was tested by the Great Southern 

Mica Co., but no regular mining was undertaken. The workings 

consist of an open cut on the summit of a ridge, another open cut 

and a tunnel about 100 yards northeast, at the end of the ridge, 

and a prospect in the hillside north of the first open cut. The open 

cut on the summit is 40 feet long, extends N. 45° E., and is reported 

to have been 25> feet deep but is now nearly filled by caving. The 

tunnel in the end of the ridge extends about 40 feet southwestwarcl 

into the ridge.

The country rock is kyanitic garnet gneiss, which strikes N. 45° E. 

and dips 45° SE. At least three bodies of pegmatite were opened 

in the different prospects. They are approximately, if not entirely, 

conformable with the bedding of the inclosed gneiss. The pegmatite in the cut on the ridge is-5 to 6 feet thick but pinches down until 

very thin at the northeast end. A quantity of good mica is reported 

to have been found here in this prospect. The cut in the end of 

the ridge exposed a body of pegmatite 2 feet thick. The pegmatite 

at the entrance to the tunnel is also 2 feet thick, but it pinches 

down smaller inside. Mica crystals 2 to 3 inches in diameter were 

seen in these workings. All the mica has a clear light rum color. 

Other prospects have been opened in the neighborhood.

N. M. McINNISH PROSPECTS.

Two prospects were opened on the land of N. M. Mclnnish, 10 

miles N. 70° E. of Lineville, west of Tallapoosa River. One of these 

was a quarter of a mile northeast of the house on a hill, and the 

other was the same distance southeast of the house on the river bank. 

At the northeast prospect a pit 7 feet deep exposes a pegmatite 6 

feet thick with included bands or horses of the gneiss wall rock striking northeast. In the prospect on the river bank another pegmatite 

outcrops with a northeast strike in the kyanite gneiss country rock. 

Only small crystals of mica were seen at each prospect, but plates as 

large as a man's two hands are reported to have been found in the 

prospect on the river. The small crystals were of clear rum color 

and had smooth, flat cleavage.

J. B. MOTES PROSPECTS.

The J. B. Motes prospects are 11 miles N. 63° E. of Lineville, west 

of Tallapoosa River. One prospect is 50 yards east and the other
40 MICA DEPOSITS OF THE UNITED STATES.

300 yards west of Mr. Motes's house. At the east prospect there is 

a 15-foot shaft and a prospect pit 50 feet northeast of it and at the 

west prospect a pit 6 feet deep. The country rock is kyanitic mica 

gneiss, which strikes northeast and dips southeast at both prospects. 

In the east prospect there is a 4-foot " vein" of pegmatite. It contains a quantity of small mica in the part exposed, and one block was 

seen that weighed 14 pounds and was more than 6 inches thick, but 

the vein would not yield sheets larger than 2 by 2 inches. A quantity 

of small mica crystals \vere thrown out from the west prospect. 

Black crystals of tourmaline, the largest 2£ inches in diameter, were

, . , . also found in

the pegmatite in 

this prospect. 

The mica from 

both prospects 

has a clear light 

rum color and 

good cleavage.

M,&G. CO.'S MINE.

The M. & G. 

Co.'s mine is 

about 2-| miles 

by road northeast of Pyriton. 

This mine has 

been worked

FIGUKE 4. Plan of M. & G. Co.'s mica mine, 2J miles northeast of niOl'6 SysteniatiPyriton, Clay County, Ala.: 1-4,. Inclines; 5, open cut. ^

cally and on a

larger scale than any other mica mine in Alabama examined by the 

writer. At the time of visit it was operated under lease by the 

Producers Mica Co., of Chicago. Since then the ownership of the 

mine has passed to William L. Halliday, of Chicago.

The mine is on the steep west slope of a narrow part of Shinbone 

Ridge about 75 feet below the summit. It was equipped with an 

engine house, shop, hoisting frame, pumps, air drills, tracks, and 

mine cars and was worked chiefly by inclines and by stopes extending 

from them. The main central incline (1, fig. 4) is 150 feet deep on 

a slope of about 30° SE. Incline 2 is 100 feet deep and incline 3 is 

40 feet deep. Large stopes were made on each side of the main incline and were connected with smaller stopes by inclines 2 and 3. 

Pillars were left in the stopes where necessary, but few were required, as the roof does not cave badly. At the time of visit the 

bottom of incline 3 was used as a sump from which to pump for the 

upper mine workings. Incline 4 Avas sunk 30 feet deep, but no stop-
ALABAMA. 41

ing was done from it. At 5 an open cut was made and a short incline extended from the inner end down to the mouth of the main 

incline.

The country rock is metainorphic schist and gneiss. Both wer<; 

removed in mining where dead wall rock had to be cut. These rocks 

are dark gray to grayish black when fresh. One specimen collected 

on the dump is fine porphyritic schist containing a groundmass of 

quartz, biotite, and muscovite, inclosing phenocrysts of quartz, feldspar, and greenish muscovite 3 to 6 millimeters across. This specimen contains scattered small grains of a sulphide, probably pyrite. 

and a little graphite around some of the phenocrysts. Another 

specimen of similar rock has " pyrite suns " one-half to one centimeter in width along a joint-plane surface. Another specimen is 

lighter colored and coarser grained, muscovite forming most of the 

phenocrysts. This specimen contains many crystalline graphite 

scales.

The schist and gneiss strike N. 45° E. and dip 30° SE. The pegmatite is conformable with the bedding of the inclosing rock. It 

ranges from 2 feet thick at incline 4 to 8 feet thick at a depth of 125 

feet on the main incline. A streak or bed of schist ranging from a 

few inches to 2 feet thick is inclosed in the pegmatite parallel with 

its walls. The formations are rather regular in strike and dip, so 

that little difficulty has been experienced .in following the " vein. 5 ' 

The pegmatite is rather fine grained. In places it is partly banded, 

especially near the walls. The crystals of feldspar range in thickness from lesg than 1 inch to 4 inches and include both plagioclase 

and microcline. Minute pink garnets in scattered grains and 

bunches more than an inch thick occur in places in the pegmatite.

The mica from this mine is of the finest quality, having a clear 

rum color and a smooth, flat cleavage. At the time of examination 

rough crystals 4 to 6 inches across formed the bulk of the output, 

but some large blocks are found. As these crystals are of good 

quality and have clean edges the waste from trimming them would 

be very small. A short time before the examination a block weighing 130 pounds and measuring 14 by 16 inches across the cleavage 

was found in the bottom of the main incline. This block would 

have yielded a number of 4 by 6 inch sheets of perfect quality. The 

Producers Mica Co. is reported to have taken out 27,000 pounds of 

rough crystal mica in November, 1914:

Another mine, the McNamara, has been developed on a fairly 

large scale about a mile west of the M. & G. Co.'s mine and it is 

reported to be on a promising deposit with a well-defined vein somewhat like that of the M. & G. Co.'s mine, but it was not examined.
42 MICA DEPOSITS OF THE UNITED STATES.

Other mica prospects have been taken up in the same general 

region in Clay County by the Southern Mica Co., of Birmingham, 

Ala. These prospects are on the properties of W. D. Dye, J. W. 

Hunter, J. W. Smith, and J. W. Brown. None of them was visited, 

but Mr. George H. Clark, a mining engineer, reported them favorably to the company.

Other prospects occur in the same region. One of these, owned 

by I. W. Ray, of Pyriton, is about half a mile northeast of the M. 

& G. Co.'s mine. Small prospects were observed along the road half 

a mile to the southwest.

J. WARREN MAY MINE.

J. Warren May, of Quenelda, Ala., opened a mica deposit near 

Flat Rock, about half a mile southeast of Pyriton, in the east side of 

a small steep valley. Two shafts, one 30 and the other 18 feet deep, 

60 feet to the northeast, were opened at the time of examination. The 

country rock is mica gneiss, which strikes N. 45° E. and dips 60° 

SE. The pegmatite veins are conformable with the gneiss. In the 

30-foot shaft there are two parallel pegmatites, one 2 to 3 inches 

thick and the other 1 foot thick separated by 1 foot of gneiss. In 

the 18-foot shaft the pegmatite is more than 3 feet thick at the 

surface and just 3 feet thick at the bottom. It incloses small streaks 

or horses of gneiss parallel with its walls. Mica was found in all the 

veins of pegmatite, even in the 2-inch vein. Most of the mica taken 

out at the time of examination was small but had a clear rum color 

and smooth, flat cleavage. Mica crystals 6 to 8 inches across are reported to have been taken out of the 3-foot pegmatite.

GIBBS LUBRICATING CO.

Several prospects were tested by the Gibbs Lubricating Co., of 

Lineville. One of these is 2 miles S. 15° E. of Lineville, along the 

property line of G. E. Moore and S. M. Cotney, and the other is near 

Flat Rock, half a mile southeast of Pyriton, on the land of J. S. 

Robertson. In the prospects near Flat Rock several pits and a shaft 

30 feet deep were very irregularly made in soft earthy formations. 

The country rock is interbedded hornblende gneiss and mica gneiss, 

which has been decomposed to soft saprolite near the workings. The 

pegmatite is approximately conformable with the bedding of the 

gneiss, striking northeast and dipping southeast. It is large, probably more than 10 feet thick, but the whole thickness is not exposed. 

The feldspar has thoroughly kaolinized. Quartz occurs in large 

segregations, one of which is 3 feet thick where exposed. A streak 

of mica crystals lies next to the quartz. Only small mica that 

would cut into sheets 1 to 2 inches square was seen, but it was of clear 

rum color and good cleavage.
ALABAMA. 43

At the prospect 2 miles south of Lineville 2 shafts were sunk about 

20 feet deep and 35 feet apart. These developed a mass of pegmatite 

with an irregular east and west strike and nearly vertical dip. The 

pegmatite incloses an irregular-shaped vein of quartz parallel with 

its walls. Bunches and scattered pockets of mica occur next to the 

quartz vein. Most of these pockets of mica consist of A, wedge, and 

bunched mica, but a little clear flat rum-colored mica is found also.

TALLAPOOSA COUNTY. 

MINES OF TALLAFOOSA MICA CO.

In 1915 the Tallapoosa Mica Co. took over the operation of 

three mines which had been worked by N. L. Baxter, of Dadeville, 

Ala. Two of these mines were worked during 1914 by Mr. Baxter 

and were visited by the writer at a time of temporary idleness. These 

are the Nelson Ware mine and the Berry mine and are described 

below.

NELSON WARE MINE.

The Ware mine is 6£ miles N. 37° E. of Dadeville, in a small but 

prominent hill. More than 30 prospect pits and shafts with irregular 

tunnels and underground workings have been made. The country 

rock is kyanitic mica gneiss. The pegmatite forms a large part of the 

summit of the hill and measures more than 100 yards north and south 

and 75 feet east and west. At the time of examination the deepest 

shafts were about 35 feet and the feldspar of the pegmatite is kaolinized to that depth. The workings are grouped about an outcrop of 

massive quartz, about 80 yards long and 50 feet wide, which forms 

the summit of the hill. The relations between the pegmatite and inclosing gneiss were not well exposed.

Most of the mica is scattered through the feldspathic content of 

the pegmatite in bunches or pockets and in single crystals that lie 

close to the quartz, but part of it< occurs in the quartz and along the 

gneiss wall rock. Some of the pockets are evidently large, for much 

mica was removed from small workings. At the time of examination 

15 to 20 tons of mica had been mined and was held ready for shipping. This rough mica should have yielded at least 2 tons of sheet 

mica and the rest should have been suitable for grinding. Much of 

the mica suitable for sheets would have trimmed to 2 by 3 inches, a 

fair proportion to 3 by 4 inches, and some larger than 4 by 6 inches. 

The mica is dark greenish-brown and is somewhat clouded with 

minute black specks of magnetite and small thin plates of pale-green 

mica or chlorite. Some of the mica might be classed as of inferior 

° stove grade, but the bulk of it is best adapted to electrical uses.
44 MICA DEPOSITS OF THE UNITED STATES. 

MRS. 1. T. BERRY'S MINEr

Three deposits of mica were opened on the property of Mrs. I. T. 

Berry, 5£ miles N. 30° E. of Dadeville. The -principal one is about 

100 yards northwest of the house in a field; the next in importance is 

on the main road about 200 yards northeast of the first deposit; 

and the third, of doubtful value, is on the east side of the road about 

50 yards northeast of the house. At the principal deposit 5 shafts 

were sunk, and underground workings were extended from them. 

The underground workings are very irregular, and as the owner 

was installing a gasoline engine preparatory to more regular operation at the time of visit the mine was idle and many of the workings 

could not be examined.

The country rock is kyanite gneiss and has a general north to 

northeast strike and an east to southeast dip but is locally nearly 

horizontal. The pegmatite is at least 8 feet thick and appears to 

be in part conformable with the inclosing gneiss. In one exposure 

it has a dip of 30° E. The pegmatite and inclosing gneiss are decomposed and soft except where greisen-like masses of quartz and 

mica have resisted weathering." In some places the mica is bunched 

thick in the pegmatite and in others there are only scattered crystals. 

The mica has a greenish-brown color and part is specked. Some 

of it occurs in sheets of good size, and the largest crystals seen 

would yield sheets 4 by 5 inches. A quantity of scrap mica was 

scattered over the dumps and probably several tons could be screened 

out.

At the prospect on the west side of the main road there was a 20- 

foot shaft, from the bottom of which an incline extended northeastward under the road. A large deposit of decomposed pegmatite in kyanitic mica gneiss was encountered. About a ton of solid 

thick blocks of rough mica had been left out. Most of it was small 

and would yield chiefly punch and scrap'material.

LOUIS TAYLOR PROSPECT.

A little prospecting was done on the property of Louis Taylor, 

7 miles N. 40° E. of Dadeville. At one place there was an 18-foot 

shaft from which a short drift was run to the east. The shaft was 

sunk in .decomposed kyanitic mica gneiss and the drift cut pegmatite, which was also decomposed. About 2 tons of rough mica, most 

of it scrap but some of it in sheets suitable for punching, had been 

left on the dump. This mica has a brownish to rum color and most 

of it contains a few small specks, though some is clear.

McCRAY PROSPECTS.

Two prospects were opened on the McCray place 5 miles N. 25° E.° 

of Dadeville. Both are on the west side of the main road,' one about
ALABAMA. 45

125 yards northwest of the house on a knoll and the other about a 

quarter of a mije northeast of the house. Both prospects are associated with the large outcrops of massive quartz. The prospect that 

makes the best showing lies northwest of the house, where a large 

deposit of quartz crops out, extending N. 20° W. along the summit 

of the knoll. The blocks and boulders of quartz cover an area about 

225 feet long and 30 to 40 feet wide. A few boulders of opaque palerose quartz were observed in this outcrop. Mica was found in decomposed feldspathic material at both ends of the quartz outcrop, 

but the best showing was in an 18-foot shaft and in two pits at the 

southeast end, where partly clay-stained mica crystals 8 inches across 

were found. This mica has a dark-green color and is heavily specked 

with small black and red oxides of 

iron between the laminae. The 

mica splits well and has soft, flexible sheets.

Only a little mica was found in 

the two pits made near the quartz 

in the northeast prospect.

0

0

a

50 100 FEET

Pit or open work

Outcrop of pegmatite

FIGURE 5. Plan of T. H. Clower inica 

prospect, 2| miles north of Opelika, 

Lee County, Ala.

T. H. CLOWEE PROSPECT.

A prospect was opened on the 

land of T. H. Clower, 2| miles north 

of Opelika. Much dead work was 

done and further prospecting would 

be required to prove the value of the 

deposits. A long trench was cut 

along the south side of a branch with two arms or trenches projecting 

from it to the south. Two other small prospect pits were made south 

of the west arm.

The country rock is n'ne-grained biotite gneiss or graywacke with 

interbedded coarse mica schist. The strike of these beds is chiefly 

north and the dip is west, but locally they lie nearly horizontal. 

About 15 feet of pegmatite having a maximum thickness of 7 

feet is exposed in the east cut. (See 1, fig. 5.) The pegmatite 

pinches out toward the south and pitches under the biotite gneiss 

toward the north. It contains quartz segregations, one of which 

where exposed is 2 feet thick, and potash feldspar crystals several 

inches across. Mica crystals 5 inches in diameter were also observed 

in the pegmatite.

In the west cut, at 2, a regular vein of pegmatite about 5 feet 

thick has been opened. This vein has been traced by pits and outcrops more than 100 feet up the hill to the south. In places it con-
46 MICA DEPOSITS OF THE UNITED STATES.

tains a quantity of small mica crystals bunched together arid but 

little intermixed with quartz or feldspar. This material would yield 

mica suitable for grinding. No pegmatite was found in the long 

trench between 1 and 2. At 3 another row of pegmatite outcrops 

indicate a third vein, but these may be part of the same vein as those 

south of 2, brought to the surface by folding. The pegmatite in most 

of the openings and outcrops is hard and but little decomposed.

About 4,000 pounds of rough mica, which would yield possibly 10 

per cent of sheet ranging from punch size to 3 by 4 inches, was taken 

from the openings. The mica would be suitable for electrical uses, 

but because of a slight clouding, due to inclusions, it would yield 

only an inferior grade of stove mica.

YARBOROTTGH, SMITH, AND NEIGHBOR PROSPECT.

A small prospect was opened by F. L. Yarborough and Dallas 

Smith, of Opelika, and R. Neighbor, of Auburn, 2£ miles N. 10° E. of 

Auburn. The prospect consisted of a pit 8 by 12 feet and 6 feet 

deep. The country rock is decomposed, coarse biotite, schist, or 

gneiss, which incloses lenses of pegmatite about conformable with 

its bedding. The gneiss strikes N. 45° W. and dips 35° NE. A lensshaped mass of pegmatite was opened by the prospect, but a thickness of only 6 inches was exposed in the bottom of the pit at the time 

of examination. This mass of pegmatite was reported to have been 

several feet thick near the surface. In places there was no feldspar 

in the pegmatite, which at this prospect was composed of intermixed 

coarse muscovite mica and quartz. This mixture graded into the 

coarse biotite schist wall rock. A surprisingly large quantity of mica 

was taken out of the prospect, some of the crystals of which measured 

7 to 8 inches across and would yield plates 2 by 3 and 3 by 3 inches. 

The mica is partly specked and slightly clouded with fine, light-colored 

inclusions. These inclusions appear to be large numbers of minute 

blisters, each one showing Newton interference rings. The mica 

splits well but is somewhat brittle.

A prospect yielding mica of a similar quality was opened on the 

land of Mr. R. Neighbor, half a mile northwest of the Yarborough, 

Smith, and Neighbor prospect.

ARIZONA.

The occurrence of mica in Arizona has been known for many years. 

In 1884 F. W. Clarke 20 reported that it was known but not worked. 

Occasional inquiries about mica have been received from Arizona 

by the Geological Survey, but no valuable deposits have been reported. During 1914 Dr. Burt Ogburn, of Phoenix, sent in speci20 Mica: U. S. Geol. Survey Mineral Resources, 1883-84, pp. 906-912, 1885.
CALIFORNIA. 47

meais found near Buckeye, Maricopa County, in the mountains on the 

south side of Gila River. The rough sheets of this mica measure 

4 to 5 inches across but have been so much crushed that none of them 

would yield material larger than punch size. This mica has a clear 

jellowish-green color where it is free from surface clay stains.

The mica belt in the Virgin Range, in southern Nevada, is said to

 extend north by east from Nevada into Arizona, but there has been 

JIG report of the opening of any prospect on the Arizona side.

Specimens of the sericite schist variety of muscovite found in that 

region were sent to the Geological Survey by Sterling C. Lines, of

 Glendale, Ariz. This variety is very similar to the sericite schist 

irom the region around Jasper, Ga., described by S. L. Galpin.21 

The Georgia sericite schist has been used, after crushing and bolting* 

for some of the purposes to which ground mica is applied. Industrial companies have experimented with the Georgia material in an

 effort to discover a source of both potash and aluminum, and a partial analysis of the Arizona sericite schist was made with this object 

in view by A. A. Chambers, of the United States Geological Survey, 

with the result shown below.

Partial ana-lysis of sericite schist from Glendale, Ariz.

[A. A. Chambers, analyst.]

Per cent.

SiO,___-______________-__________________ 46.10

A1203 (+T10,, P20B, etc.)________._____-_____ 36.34 

Total iron______________________________ 2. 48

Na-0 _____________-______-___________ 2.11 

K20 ________________-___- ____________ 10.01

This analysis corresponds rather closely with that of the Georgia 

rock, both containing over 10 per cent of potash and 34 per cent of 

alumina.

The schist has a silvery, greenish-gray color, is foliated and has a 

crinkled structure. A number of the cleavage surfaces show small 

ripple-like folds in two directions. Some of the specimens have a 

few flattened lenses of quartz lying parallel with the schistosity; 

others, probably from the border of the bed of pure serioite schist, 

contain rather numerous phenocrysts of both quartz and feldspar 

with the sericite wrapped around them.

CALIFORNIA. 

GENERAL FEATURES.

So far as can be learned the only serious attempt to mine mica in 

California was made by the Mount Alamo Mining Co., at a place in

21 A preliminary report on the feldspar and mica deposits of Georgia : Georgia Geol. 

Survey Bull. 30, pp. ir.3-155, 101 o.
48 MICA DEPOSITS OF THE UNITED STATES.

Ventura County, from 1902 to 1904. Prospects have been found at 

other places, and according to reports a little mining was attempted 

at some of them.

F. W. Clarke 22 in 1884 mentioned the occurrence of mica deposits 

near Gold Lake, Pluma County; in the Ivanpah district, San Bev - 

nardino County; near Susanville, Lassen County; near Tehachapi 

Pass, Kern County; in the Salmon Mountains. Siskiyou Countyand in Eldorado County. The deposits of the Salmon Mountains-- 

were tested in 1885 but without good results.

A deposit was reported as being tested on the land of George Simmons, 6 miles west of California Hot Springs,23 Tulare County, in 

1903. In 1902 mica deposits were reported 6 miles east of Soledad,2 * 

Monterey County. According to the lithologic map compiled by 

G. A. Waring,25 the rock formations 6 miles east of Soledad are of 

comparatively recent age, chiefly Cretaceous or Tertiary, in which 

one would not expect to find mica deposits. The same map shows art 

area of granitic rocks including gneisses and schists, in which micabearing pegmatites might occur, within 6 miles west of Soledad.

According to the State mineralogists 26 50 tons of mica was produced in California in each of the years 1902, 1903, and 1904. worth 

$2,500, $3,800, and $3,000, respectively. Much of this mica probably came from the Mount Alamo Mining Co.'s mine in Ventura, 

County.

VENTURA COUNTY. 

MOUNT ALAMO MINING CO.

The work of the Mount Alamo Mining Co. has been briefly 

described, in part anonymously and in part by the mine superintendent, A. J. Hoskins.27 The mine is on Piru Creek, nearly 60 miles 

south of Bakersfield and the same distance west of Lancaster, the 

shipping point. Mount Alamo, or Alamo Mountain, from which 

the company took its name, is in Ventura County 12 miles S. 20° W. 

of the corner of Los Angeles, Ventura, and Kern counties. Work 

was stopped in 1905, and the mine has since been idle. The work 

is said to have been carried to a depth of 200 feet on a large body 

of pegmatite inclosed between a mica schist hanging wall and a 

granite footwall. The mica was shipped to the company's plant in 

West Berkeley, Calif., and there prepared for use in electrical work. 

The mine yielded chiefly scrap mica suitable for grinding. A

22 Op. cit, p. 907, 1885.

M Eng. and Min. Jour., vol. 75, p. 496, 1903. 

2* Idem, vol. 74,, p. 559, 1902.

25 Springs of California: U. S. Geol. Survey Water-Supply Paper 338. 1915. 

M Mineral production of California in 1902, 1903, and 1904: California State Min. 

Bur. Bulls. 29, 39, and 41.

=*Min. and Sci. Press, vol. 90, p. 69, 1905.
COLORADO. 49

quantity of small sheet mica was obtained, part of which was thin 

split'and built up into mica board. Some good sheet mica was also 

mined, yielding- plates ranging from 2 by 3 to 4 by 10 inches.

COLORADO.

OKNERAL FEATURES.

Deposits of mica have been found in many parts of Colorado. 

Some of them have only been prospected and others have been 

worked on a fairly large scale. The deposits are widely scattered, 

occurring in areas of older gneisses and schists extending along the 

front ranges of the Eocky Mountains from Larimer County to 

Premont County and westward into Routt, Lake, and Chaffee

-counties. A few deposits occur in isolated outcrops of older rocks, 

such as those near Grand Junction, in Mesa County.

Some of the occurrences have been known for many years. Albert 

^Williams 28 mentions mica deposits in Boulder, Jefferson, and 

Fremont counties in 1882. The following localities are mentioned 

'by J. A. Holmes 29 in 1899:

In Colorado mica deposits have been examined at the following points: (1) 

IsTear Floyds Station, on the Union Pacific, Denver & Gulf Railroad, 5 miles

 east of Idaho Springs; (2) at the-Terrill mica mine, 18 miles west-northwest 

of Golden, on the Blackhawk road, where the dike is 60 feet wide and shows 

considerable quantities of fairly good mica, and the Scheller mine in the same 

region, 8 or 9 miles west-northwest of Golden; (3) the Beers mica mine 

(Princess lode), on Soda Creek, 3 miles south of Idaho Springs, where a 

slightly specked but otherwise good mica occurs in an 8-foot dike; (4) the 

Mi Wot mica mine, in the Central mining district, some 15 miles northwest 

of Boulder, where the dike has a width of 50 to 60 feet, and in portions of it 

mica of fair quality is abundant; (5) the Pearl mica mine, 9 miles southwest of Leadville and on the north slope of Mount Massive; (6) the Snavley 

ramie, 9 miles northwest of Cripple Creek; (7) High Creek mine, 4 miles 

southwest of High Park, in the Cripple Creek district.

At the two last-named localities a considerable quantity of mica has been 

exposed but is extensively ruled and in irregular wedge-shaped blocks. At 

the other localities mentioned the mica shows less' ruling, though the feature 

is fairly common at all these places, but at each of them the indications for 

successful mining operations are sufficiently favorable to warrant more extensive developments.

The mica deposits of Colorado have yielded good sheet mica of 

merchantable sizes, but a study of the different deposits described 

below leads the writer to believe that as a whole they yield an unusually large proportion of scrap mica. Some of the deposits yield 

mica suitable only for grinding and others yield but a small propor-

. » Mica : TJ. S. Geol. Survey Mineral Resources, 1882, pp. 583-584, 1883.

20 Mica deposits in the United States : U. S. Geol. Survey Twentieth Ann. Rept., pt. 6 

< oou t..), p.. X07, 1899.
50 MICA DEPOSITS OF THE UNITED STATES.

tion of sheet mica and none of large size. Several of the deposits 

have produced sheet mica of good quality and large size. The large 

yield of scrap mica from the Colorado mines has led to the building 

of grinding mills in many places in the State, some near the mines 

and others in towns or cities. Few of the mills are now in operation, 

and a large part of the mica produced in Colorado is shipped to Chicago or eastern points.

CHAFFEE COUNTY.

A hydrated form of biotite mica found about 5 miles southeastward of Hecla, in the Turret mining district, has been used in the 

industries during the last few years. The material is mined and 

handled under the name of tung ash by the Denver Mining & Manufacturing Co. By calcining the mica as it comes from the mines 

and then crushing and sizing, a ground product with a rich goldenbronze to silver color and metallic luster is obtained. This is suitable for various decorative purposes. Because of the expansion? 

and exfoliation the mica undergoes when calcined, a little of the 

crude product will make a large quantity of the calcined product. 

The finished tung ash is light, and a small quantity will spread over 

a large surface.

According to Mr. W. W. Kirby, secretary of the company, the 

mica is found in veins that lie between gray granite and hard black 

schist and that reach in places a thickness of 4 feet. It occurs in 

shoots about 40 feet long, very much like ores in metalliferous veins,, 

and forms solid masses of crystals, the largest 2 or 3 inches ini 

diameter, bunched together at different angles. In the parts between the ore shoots a similar variety of mica forms about 50 per cent 

of the filling. The mica is greenish to brownish black. The folia are 

flexible and inelastic. When heated they swell and exfoliate very 

much like vermiculite. The laminae of the calcined product are 

sufficiently separated and brittle to break down into a fine scaly product, which exhibits the colors and luster already mentioned.

FREMONT COUNTY.

More mining for mica has been done in Fremont County than in 

any other county in Colorado. The principal mines in this county are 

those that work deposits in the Micanite region, about 25 miles 

northwest of Canon City. Other deposits have been worked in the 

dissected plateau north of the Royal Gorge and within 2 miles of 

the rim, 7 or 8 miles by road northwest of Canon City. One of 

these deposits, the Mica Hill mine, yields only scrap mica for grinding but is of interest because of the abundance of this material. 

Another prospect of this kind is the Wild Rose claim, 6 miles north 

-of Texas Creek.
COLOKADO. 51

The deposits have been prospected or worked at different times, 

but mica mining in Fremont County was most active from about 

1904 to 1907. During this period the United States Mica Co., of 

Chicago, 111., operated the mines of the Micanite region, and the 

Canon City Mica Mining & Mills Co. operated the Mica Hill mine. 

The United States Mica Co. had an elaborate trimming plant and a 

dry grinding mill near the mines. The Canon City Mining & Mills 

Co. had a dry grinding mill and an experimental plant in Canon 

City to develop uses for the product. None of the mines were in 

operation in 1908 and 1913.

MICANITE REGION. 

MINES OF UNITED STATES MICA CO.

Location of mines. The mines of the United States Mica Co. are 

on the east side of Mac Gulch, a tributary of Currant Creek, about 2 

miles south of the Park County line and about 25 miles northwest of 

Canon City. The Micanite post office was formerly near the mines 

but is now 3 miles east of it, on West Fork of Wilson Creek. Thedeposits are in rough, mountainous country at elevations of 7,900 to8,400 feet above sea level. The names and present owners of all 

the claims could not be learned. The old Micanite post office and mica 

shops are in the gulch, and the position of the different workings 

examined can be described with respect to them. The most northerlyworking is about three-quarters of a mile north of the shops, in thesteep east wall of the gulch, probably 300 feet above the bottom. In. 

the following descriptions this working will be called the North 

mine. Mine No. 8 of the United States Mica Co., at the time of examination claimed by Thomas Pennington and Luther Seymour 

under the name Climax, is about 250 yards east of south of the North 

mine, in less broken country, near the summit of the ridge. Another 

working, which will be called the East mine in the description below,, 

is nearly a quarter of a mile east of the Climax or No. 8, on the 

west side of a small gulch tributary to Mac Gulch. Another deposit 

was opened by the United States Mica Co. on the summit of thenarrow ridge east of the shops, about two-thirds of a mile south 

of the Climax working. This will be called the South mine. Two 

prospects have been opened by F. L. Eowe, of Micanite, one about 

150 yards south of the South mine on the point of the ridge, and 

the other a quarter of a mile to the southeast, in the east side of the 

gulch. Still other prospects are reported to have been opened in the* 

region by the United States Mica Co.

North mine. The North mine was worked by an open cut and. 

tunnels in a northerly direction along the steep mountain side.. 

Crosscuts and pits were made on the west or lower side. The opem
52 MICA DEPOSITS OF THE UNITED STATES.

cut is about 100 feet long and of irregular shape. It has a depth of 

25 feet in places, but caving of the walls has filled parts of it. The 

dumps on the mountain side are large.

The country rock immediately around the mine is composed of 

biotite schist and gneiss with streaks of muscovite schist having a 

porphyritic texture due to inclusions of small feldspar crystals. The 

formation strikes about north and dips 35° W. The pegmatite body 

is probably 30 feet thick and of irregular shape. It cuts the gneiss 

with an irregular but low dip. The component minerals of the pegmatite are in some places segregated into irregular masses and in 

others they occur in the usual mixture. Along the west side of the 

open cut there is a mass of quartz at least 20 feet thick and probably 

50 feet long.. This quartz is chiefly white, but in places it is pale 

pink. The pegmatite was richest in mica on the east side of the 

quartz, but pockets of mica were also mined along the west side and 

to the north of it. Both pink orthoclase and white albite or other 

plagioclase feldspar were observed in the pegmatite. Beryl and 

apatite were noted as accessory minerals. Fragments of opaque 

bluish-green beryl crystals 5 inches in diameter were found on the 

clump. Two badly fractured crystals of apatite, about 12 and 18 

inches across, were seen in the massive quartz. The crystals were 

opaque and contained both green and pink apatite. Most of the 

mica left around the mine was wedge, fishbone, and small plates 

suitable chiefly for grinding.

Climax claim or mine No. 8. The Climax claim or working No. 8 

of the United States Mica Co. was worked by three open cuts with 

connecting tunnels, some smaller cuts or pits, and a tunnel at a lower 

level. The workings fall within an area about 100 feet long from 

north to south and 50 feet wide, and their positions are shown in the 

rough sketch (fig. 6).

The lower tunnel is about 15 feet below the level of the floor of 

the larger open cuts (1 and 2 in the figure). It is about 60 feet long 

and branches at the end as shown. Open cuts 1 and 2 are from 10 to 

15 feet deep and are connected with No. 3, which is at a little greater 

elevation, by an inclined tunnel or raise.

The country rock is diorite gneiss with streaks of biotite schist 

and gneiss. The pegmatite dike is probably 25 feet thick and cuts 

the inclosing gneiss irregularly. In the open cuts it appears to dip 

15°-20° E., but the lower contact exposed in the end of the tunnel 

is irregular and rolling, as shown in figure 6. The pegmatite is 

coarse grained and has an irregular texture. Parts of it consist of 

the normal mixture of feldspar, quartz, and mica, but other parts 

 contain large crystals and segregations of these and other minerals. 

Quartz occurs in masses 10 feet across, feldspar in crystals a yard
COLORADO. 53

through, and mica in blocks weighing 50 pounds or more. Imperfect 

crystals of mica 18 inches across and 6 to 8 inches thick and masses of 

wedge-shaped crystals 2 feet across had been left exposed in the 

face of the pegmatite in the open cuts. An unusual feature of this 

pegmatite, one without economic value, is the inclusion of cordierite 

crystals or masses, some nearly a yard across, in various stages of 

alteration. This cordierite occurs in contact with all three minerals 

of the pegmatite that is, the feldspar, quartz, and mica. Part of 

it is fresh and glassy and has a gray to dark violet-blue color in thin 

pieces. Much of the cordierite has altered to muscovite (often called 

pinite) and some has been only partly altered. Alteration has taken

Mica schist

FIGUBE 6. Plan and cross section of Climax mica claim or working No. 8 of United States 

Mica Co., 25 miles northwest of Canon City, Fremont County, Colo. A, Plan of workings ; B, cross section in end of tunnel; 1, 2, 3, open cuts; 4, 5, 6, small cuts or pits; 7, 

tunnel.

place along numerous parallel cleavage planes, and the surfaces of 

these planes are heavily coated with mica. The effect of these 

numerous cleavages with their reflection from mica-coated surfaces 

in the glassy cordierite is striking.' In some places entire £ordierite 

crystals have altered to masses of brownish-stained mica which still 

preserve the prominent cleavage planes of the cordierite as thin 

layers of mica schist with smaller crystals of mica developed between 

them. Green apatite was found in some of the pegmatite in crystals 

as much as 2 inches in diameter.

The product of this mine would include both sheet mica and scrap 

mica for grinding. Many of the large mica crystals have been

111375 23- 5
54 MICA DEPOSITS OF THE UNITED STATES.

badly ruled and others have imperfections, such as the A structure 

and hair lines. Some of the sheet mica is partly specked with thin 

films of magnetite between the laminae. Rough sheets of mica 

several inches across were seen around the mine, and a specimen was 

picked from the pegmatite that would cut into clear sheets 2 by 5 

inches. There would be a large proportion of scrap mica in trimming the sheet mica, and this with the masses of wedge-shaped mica 

crystal would form an important part of the output of the mine.

East mine. The East mine was worked by a short tunnel and 

several small open cuts in an easterly direction down a spur on the 

east side of a ridge of moderately steep slope. The country rock is 

coarse biotite granite containing pink or red feldspar. The pegmatite dike is large and is composed of dark-red coarse feldspar 

crystals and irregular quartz masses with bunches of pockets of 

small wedge-shaped mica crystals. No mica of sufficient 'size to cut 

into sheets was seen at the time of examination, but the wedgePegmatite v

FIGURE 7. Plan and cross section of South mine of United States Mica Co., 25 miles 

northwest of Cauon City, Fremont County, Colo. A, plan ; B, cross section, looking 

north.

shaped crystals would be suitable for grinding. Biotite mica, a little 

green apatite, and small fragments of feldspar with bright-green 

copper stains were seen in the pegmatite or on the dump.

South mine. The South mine was worked by an open cut with 

short tunnels near the summit and along the west side of a small 

knob on a ridge. The open cut is about 45 feet long in a northnorthwest direction, 15 to 20 feet wide, and 10 to 25 feet deep. Crosscut trenches were made at each end of the open cut to the hillside 

on the west for the removal of waste and ore, as shown in figure 7, a. 

An inclined track connected the mine with a grinding mill in the 

valley a couple of hundred feet below.

The country rock is coarse biotite granite, characterized by pink 

feldspar and an abundance of biotite. The pegmatite consists of 

the unusual mixture of quartz and feldspar with mica unevenly distributed through it. The feldspar is dark-pink or red orthoclase or 

microcline. The pegmatite mass is large and irregular in shape and 

has streaks of pegmatite and aplite from 2 inches to more than a
COLORADO. 55

foot thick extending from it into the granite below, as shown in the 

section in figure 7. The pegmatite apparently forms a large bulge 

or body cropping out at the present surface and surrounded by 

granite below and on the sides. There seem to be transitional phases 

between the pegmatite and aplite, and the streaks of these rocks may 

represent feed channels for the main body of pegmatite or may be 

offshoots from that mass.

Most of the mica obtained from this mine was small and in wedgeshaped crystals suitable only for grinding. Evidently a large pocket 

was found, but this was exhausted and considerable exploration; 

work was done in search of other pockets. A little biotite mica was 

associated Avith the muscovite mica in this mine.

ROWE MINE.

At the north working of the F. L. Rowe mine an open cut was 

driven about 35 feet S. 80° E. into the side of the ridge, with a 

short tunnel and an 18-foot raise to a small open cut above. The 

biotite granite country rock is cut by two streaks of pegmatite, 

the upper one 10 feet thick and the lower about 25 feet thick. The 

west contact of the lower pegmatite strikes N. 25° W. and dips irregularly eastward. The pegmatite masses have a very uneven texture 

and contain segregations of both quartz and dark-pink feldspar 3 

to 4 feet across. The mica occurs chiefly in wedge-shaped and ruled 

crystals suitable only for grinding as scrap. Some of it is specked. 

Several tons of mica was left around the workings.

The other prospect of F. L. Rowe, a quarter of a mile to the southeast, was not examined.

ROYAL GORGE REGION.

Mica Hill. Mica Hill is about 7 miles, by fairly good wagon road, 

northwest of Canon City and about 2 miles north of the rim of the 

Royal Gorge. It is an oval hill that rises about 150 feet above 

the road in the valley on the south. The summit is formed by a 

mass of pegmatite about 100 feet thick and two or three times as 

long. The pegmatite and the hill have an east by north elongation, 

corresponding roughly with the average strike of the country rock, 

which is crumpled biotite gneiss with an east-northeast strike and 

a high northerly dip. There are masses of granite and diorite in 

the vicinity. About 200 yards east of Mica Hill is a similar hill, 

formed by the outcrop of a mass of pegmatite, in which lithia mica 

(lepidolite), pink and green tourmaline crystals, and fremontite 30 

have been found. The pegmatite of Mica Hill is composed of large

80 Schaller, W. T., The amblygonite group of minerals fromontite (=natramb)ygonite) : U. S. Geol. Survey Bull. 610, pp. 141-142, 1016.
56 MICA DEPOSITS OF THE UNITED STATES.

masses of feldspar and quartz, graphically intergrown in places, 

and of irregular masses and streaks of solid mica. The masses and 

streaks of mica occur in massive feldspar and range in thickness 

from 2 to 10 feet. The mica is in the form of wedge-shaped blocks 

having fishbone structure and in twisted plates bunched together 

at all angles. In places a little biotite or black mica is mixed 

through the white mica, so that it is necessary to hand-cob part of 

the material after crushing before grinding. The solid mica is 

plentiful in the better exposures, and 200 tons is reported to have 

been obtained from a small opening in the south face of the hill 

near the summit. A supply sufficient to keep a grinding mill in 

operation for many months is exposed in the working faces and outcrops of the pegmatite. In small openings lower down rough crystals 

of beryl from an inch to a foot in diameter and columbite in masses 

weighing 2 or 3 pounds, were found.

Other prospects and mines were opened near the edge of the Royal 

Gorge about half a mile west of the point where visitors view the 

gorge from its rim. These prospects were not examined.

TEXAS CREEK REGION.

Wild Rose claim. The Wild Eose claim was located by J. D. 

Endicott, of Canon City, both for its mica and rose quartz. It is in 

the steep west wall of East Gulch, about one-third of a mile from its 

junction with Echo Canyon nearly 6 miles north of Texas Creek. 

Transportation facilities were poor when the claim was visited, part 

of the distance to the railroad at Texas Creek being covered by a 

trail. The deposit is 300 or 400 feet above the bottom of the 

gulch and consists of a large mass of pegmatite that crops out in 

a northerly direction along the mountain side and reaches in places 

a height of 25 feet. The pegmatite is inclosed in contorted mica 

and cyanite or fibrolite gneiss and schist in which hornblende schist 

streaks are also included. The most prominent feature of this 

deposit is a large segregation of quartz, which outcrops for a dis-" 

tance of 150 feet and reaches a height of 20 feet. Most of the quartz 

is white to pink, but some has a fairly deep rose color and is suitable 

for gems. The mica occurs in irregular streaks containing solid 

masses of twisted and wedge-shaped crystals. These streaks vary 

from 1 foot to more than 6 feet in thickness and occur in both quartz 

and feldspar. The solid mica at this time does not appear to include any biotite and is therefore well adapted to grinding without 

other preparation than crushing. The claim has not been worked 

commercially, but the solid mica should not be difficult to mine as 

long as the streaks or masses hold out, and these would supply the 

demand of an ordinary grinding mill for a considerable time.
COLORADO. 57

JEFFERSON COUNTY. 

LOCATION OF DEPOSITS.

Mica has been mined or prospected at several places in Jefferson. 

County. Two deposits southwest of Morrison were examined the 

Bigger mine, about 9 miles southwest of Morrison, and the Thomas 

mine, about 12 miles west-southwest of Littleton. These mines are 

in rough mountain country a few miles west of the first foothills 

scarp of the Rocky Mountains. According to F. W. Clarke 31 a mica 

mine was opened on Turkey Creek in 1884. This was probably the 

Bigger mine, which is reported to have been first opened about that 

time in search of tin ore. No tin ore was found, but a deposit of 

mica was proved.

BIGGER MINE.

The Bigger mine is on the south side of a tributary of Turkey 

Creek at the edge of a broken plateau about 7,100 feet above 

sea level. It is about half a mile from a good road along Turkey 

Creek to Morrison. A passable wagon road could be made to the 

mine at small expense. The developments consist of a deep shaft 

with a tunnel from the hillside to an upper level, an open cut northwest of the shaft, and an irregular set of "ground-hog" workings 

southeast of the shaft. The shaft is reported to be 80 feet deep but 

is filled with water to within 30 feet of the surface. The tunnel 

from the hillside on the northeast is about 50 feet long and only about 

15 feet below the surface. It has caved in badly. Other short tunnels were made from the shaft at this level. The open cut to the 

northwest is about 35 feet long and 10 feet deep. The " ground-hog " 

workings are about 100 feet southeast of the shaft and consist of an 

irregular-shaped open cut about 20 feet deep with short drifts and 

rooms.

The country rock is chiefly diorite cut by reddish granite. The 

pegmatite crops out in a large bed that is nearly horizontal or has 

a slight southerly dip. This bed forms a small scarp along the edge 

of the valley and is therefore in a very favorable position for development by open work or tunnels. The lower contact of the pegmatite is concealed by soil and vegetation, but the bed must be at least 

25 feet thick. The shaft cut through pegmatite into the underlying 

diorite, but at what depth 'could not be determined. The pegmatite has an exceedingly variable texture, and in places the segregations of the different component minerals are large. Masses of pink 

orthoclase or microcline feldspar, 8 feet thick, composed of several 

large crystals and irregular segregations of quartz, some with a 

pale rose tint, of similar size, were encountered in the workings.

81 Mica: U. S. Geol. Survey Mineral Resources, 1884, pp. 906-912, 1885.
58 MICA DEPOSITS OF THE UNITED STATES.

Mica occurs in large aggregations or deposits of wedge, A, ruled, 

and fishbone crystals. These deposits are irregular in shape and 

range from 1 foot to 8 or 10 feet in thickness and 15 to 20 feet 

in length. They both occur among the large masses of feldspar 

and quartz. Beryl crystals are abundant and probably more than 

2 tons are in sight on the dumps and in thQ workings. The beryl 

crystals seen were opaque and ranged from 4 to 18 inches in diameter. 

Black tourmaline was found in a small pit east of the main workings, but most of the small quantity of muscovite mica discovered 

was associated with biotite mica.

The mica from the Bigger mine is practically all suitable only for 

grinding. A little small-sheet or punch mica might be cut from 

some of the crystals, but that would be a very small proportion of 

the production. Scrap mica can be mined in a nearly pure form, 

which would not require much cleaning before shipping or grinding. 

As long as such large pockets of mica as were exposed in the workings at the time of examination could be found, scrap, mica could 

be mined cheaply.

THOMAS MINE.

The Thomas mica mine is in the steep slope of the west side of a 

tributary of Deer Creek, about 1| miles southeast of the Bigger 

mine. It has been worked by an open cut 15 to 30 feet wide, extending for a height or distance of about 50 feet in a N. 60° W. direction up the hill, with two short tunnels and a room stoped out near 

the bottom of the cut. A small cleaning mill had been erected near 

the lower tunnel.

The country rock is schistose diorite cut by reddish granite. The 

pegmatite and the inclosing diorite have been partly decomposed. 

Sufficient work had not been done to expose the attitude of the pegmatite toward the inclosing rock. One contact between pegmatite 

and country rock had a strike of N. 30° E. and a dip of 70° SE. 

The schistosity of the inclosing diorite strikes N. 60° .W. and has 

a vertical to high northeast dip. Much of the pegmatite has a 

rather fine, even grain, but some is very coarse and variable in texture, with large feldspar crystals, masses of quartz, and bunches of 

mica. The mica obtained is chiefly small, owing to the excessive 

ruling of the larger crystals. Some punch and small-sheet mica 

could be mined, but the principal returns would be obtained from 

the scrap mica. The quality of some of the small-sheet mica is 

excellent, the color being a clear rum and the cleavage perfect. 

Among other minerals observed in the pegmatite were numerous 

opaque red garnets and a little apatite*.

Apparently scrap mica was rather plentiful in parts of the pegmatite. Much of the pegmatite was crushed in the upper part of
COLORADO. 59

the mill, and the product was distributed by gravity over coarse 

sieves below, where the mica was separated from it.

LARIMER COUNTY. 

BUCKHORN MINE.

Considerable work was done several years ago by the Buckhorn 

Mica Mining & Milling Co. on a deposit about 17 miles in an air 

line S. 75° W. of Fort Collins, on North Fork of Buckhorn Creek. 

This deposit, which was discovered in 1884, lies in an oval hill whose 

longer diameter extends N. 65° E. and is about 200 feet higher than 

the camp and mill, which are a quarter of a mile north of it in the 

valley below. The camp is about 8,000 feet above sea level. Fires 

have damaged much of the timber, but sufficient is left on the mountains for use in mining. A fair road was 

built from the mine 

to Masonville, about 

12 miles to the southeast, but the bridges 

and some of the grades 

were in bad repair at 

the time of examination, in 1913.

The mine was 

worked by open cuts, 

two shafts, drifts, 

trenches, and pits in 

a N. 65° E. direction 

along the summit of 

the hill. The position of the workings is shown in figure 8, in which 1 

is a crosscut trench or open cut; 2 an open cut 90 feet long, 10 feet 

wide, and 2 to 15 feet deep; 3 an open cut 20 feet long and 8 feet deep; 

4 a shaft (now boarded up) in the end of a crosscut tunnel; 5 a shaft 

filled with water within 25 feet of the surface; 6 a crosscut trench 

20 feet long and 3 feet deep; and 7 two prospect pits. Drifts were 

made from the interior shaft (4) on the vein. It was not possible to 

see much of the underground workings, but the size of the dump indicates that they were rather extensive.

The country rock is chiefly quartz-biotite schist. The pegmatite 

is approximately conformable with the foliation of the schist, striking about N. 65° E. and having a nearly vertical dip. The contact 

between the two rocks is sharp. The pegmatite varies in thickness 

from about 9 feet in the open cut marked 1 to 20 feet in the other 

open cuts, 2 and 3, and about 10 feet in the prospect pits, ,7. It is a

FIGURE 8. Plan of workings of Buckhorn Mica Mining 

& Milling Co., 17 miles S. 75° W. of Port Collins, Larimer County, Colo.
60 MICA DEPOSITS OF THE UNITED STATES.

variable mixture of gray quartz, albite feldspar, pink orthoclase or 

microcline feldspar, mica, and a few accessory minerals such as beryl 

and black tourmaline. The mica occurs in bunches or pockets, some 

of them several feet thick, in which there is not much gangue mineral, 

and in separate crystals distributed irregularly through the pegmatite. The pockets are filled chiefly with wedge, A, fishbone, and 

ruled mica in crystals ranging from those of small size to some 

several inches across. In some of the A mica thin plates of albite 

were observed between the laminae. Blocks of light-greenish compact massive mica have been thrown on the dumps. This is composed almost entirely of mica in scales of various sizes, some minute 

and some one-eighth of an inch in diameter, with but few impurities 

intermixed. Pale-greenish to white beryl crystals several inches 

across were observed in the pegmatite in the open cut. In places 

black stains of manganese oxide have penetrated into the seams in 

the pegmatite. The mica-quartz schist wall rock in one place has 

been strongly metamorphosed by the pegmatite, and much small 

black tourmaline has been deposited in the bedding planes and 

through the layers of schist.

The mica from this mine is light green, but very little of it is suitable for sheets. It is of a good grade for grinding for wall-paper 

decoration, because of its light color and brilliancy. Possibly the 

fine compact variety mentioned above would be suitable for grinding and might be found in large quantity. No rich pockets of mica 

were left exposed in the workings, and little idea could be formed as 

to the yield to be expected. Several tons of good scrap mica had been 

left on the storage floor of the shop at the mine and several tons more 

in the bins at the mill.

The mill erected on the property was operated by steam engine and 

was equipped with dry-grinding machinery. The mica was ground 

with a Raymond patent pulverizer No. 0 and conveyed to a Barnard 

& Leas bolter by air draft from a rotary blower. The capacity of the 

mill was limited by that of the bolter to 1£ tons a day. The pulverizer could have supplied two or more bolters.

Another mica prospect was opened by Parkson & Kitchen about 

a quarter of a mile west of the Buckhorn mine. The work consisted 

of an open cut on a bulge of pegmatite nearly 30 feet across. The 

pegmatite has a northwesterly strike and is inclosed in biotite gneiss. 

An irregular streak or pocket of mica, about 6 feet thick, extended 

across the pegmatite in a northeasterly direction. Green and yellow 

opaque beryl ranging from thin films to crystals 2£ inches in diameter were found. Orange-colored and yellow ocherous stains of 

uranium were seen in a few pieces of pegmatite on the dump. These 

were reported to surround small cores of a heavy black mineral.
COLORADO. 61

which might be pitchblende. The mica obtained resembles that of 

the Buckhorn mine and is practically all suitable only for grinding.

MESA COUNTY.

A deposit of mica was located some time prior to 1895 in Ladder 

Canyon, Mesa County, 8 miles south of Grand Junction, Colo. The 

deposit is said to have been discovered by Benton Cannon, but is now 

held by 8. A. Grady, of Grand Junction. The locality was reached 

in 1911 by trail only, though a road was once made up the canyon 

within half a mile of it. The trail leaves the Grand Junction road 

and enters the canyon about a mile north of the prospect. This part 

of Ladder Canyon is from 200 to 300 feet deep.

The development consists of a short tunnel about 10 feet long and 

an open cut about 25 feet long in the side of the canyon. The deposit 

occurs in a dome of pre-Cambrian rocks exposed in the bottom and 

lower walls of the canyon. Red sandstone, probably of Carboniferous age, overlies the dome and forms the country rock of the region, 

even outcropping in the bottom of the canyon one-third of a mile 

farther north. Near the mica prospect the older rock outcrop to a 

height of 100 feet in the canyon walls. They consist of biotite and 

muscovite schist and gneiss cut by pegmatite. The pegmatite is more 

than 200 feet wide in the bottom of the canyon and is thinner at the 

top of the exposure. Apparently it is at the top of an anticline 

whose axis strikes nearly east and west. The main anticline has 

smaller folds upon it and the pegmatite exhibits these irregularities. 

The minerals of the pegmatite are segregated in large masses. The 

feldspar is chiefly the potassium variety and has a pinkish or flesh 

color. It occurs in an irregular mass or streak more than 10 feet 

thick in the interior of the pegmatite and grades into material containing considerable quartz or with the composition of ordinary 

pegmatite. A large segregation of massive quartz, the thickness of 

which is not exposed, lies below the feldspar mass, and more massive 

quartz overlies it. A few blocks of translucent rose-colored quartz 

were observed in the bottom of the canyon, but the quartz is too pale 

for use as gem material. The upper part of the pegmatite outcrop is 

concealed by talus from the overlying red standstone.

The mica occurs principally along the contact between the feldspar 

and quartz masses, where it forms an almost continuous streak across 

the face of the pegmatite outcrop. (See fig. 9.) The mica streak 

ranges from 1 foot to 3 feet in thickness and is composed of nearly 

solid masses of mica crystals. These crystals range from less than 1 

inch to more than 1 foot in length and are more commonly arranged 

in tufts and radiating groups. In places quartz, feldspar, and black 

tourmaline are associated with the mica. Rosettes of radiated mica
62 MICA DEPOSITS OF THE UNITED STATES.

crystals cover the south wall of the open cut for a space 12 feet long 

by 8 feet high. The mica in the face of this cut is shown in Plate IX, 

A. The exposure here gives an impression of a very thick mica 

streak, but an examination shows that the cut has opened the " vein " 

along its wall. The full thickness of the streak of mica is not exposed 

but is probably 3 feet or more. The mica crystals are much ruled and 

broken and nearly all have either the A, wedge, or herringbone structure. It is probable that the entire yield of mica from this deposit

wiN ke suitable for 

grinding only, and 

that little if any 

mica valuable for 

cutting into sheets 

will be obtained. 

The quantity of 

scrap mica for 

grinding that can 

be mined near the 

surface is considerable.

CONNECTICUT. 

GENERAL FEATURES.

Mica of rather 

inferior quality has 

been obtained in 

variable quantities 

as a by-product 

from some of the 

quarries operated 

for feldspar and 

gems in Middlesex, 

Hartford, and New 

Haven counties, 

Conn., and sheet mica of good quality has been found at the Roebling 

mine near Merryall, Litchfield County. Undesirable features that 

are common in the mica of Connecticut are the widespread development of the A, wedge, and tangle-sheet structure, ruling, hardness, 

and brittleness of the plate. The mica is saved at the feldspar quarries, and after a stock has accumulated most of it is sold in bulk in the 

rough at the market price for scrap mica. The principal quarries of 

Middlesex, Hartford, and New Haven counties have been described

FIGURE 9. Outcrop of irregular streak of mica between 

quartz and feldspar in S. A. Grady claim, Mesa County, 

Colo.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE IX

A. MASS OF SOLID MICA EXPOSED IN OPEN CUT AT GRADY MICA MINE, MESA

COUNTY, COLO.

B. VIEW NORTHWARD TOWARD OPEN CUT IN PEGMATITE INCLOSED IN MICA 

GNEISS, TEXAS MICA CO., CULBERSON COUNTY, TEX.

Hills capped wilh sedimentary rock in background.
U. S. GEOLOGICAL SURVEY 

BLOCK OF SOLID MICA BLASTED LOOSE FROM PEGMATITE AT GEORGE ROKBLIN
CONNECTICUT. 63

by E. S. Bastin,32 and the following descriptions of the deposits in 

those counties are abstracted from his report supplemented by notes 

made by the writer regarding the Gillette and Strickland quarries, in 

Middlesex County.

LITCHFIELD COUNTY.

GEORGE HOBBLING MINE.

A mine was operand for mica and feldspar near Merryall, Litchileld County, between the years 1880 and 1900, in which gem beryl

EXPLANATION

Solid mica 

Strike and dip

Strike of 

vertical bed

0 50 100 200 300 Feet

FIGURE 10. Plan of George Roebllns mica, feldspar, and beryl mine near Merryall, 

Litchfield County, Conn., showing part of geology.

proved to be a valuable by-product. The beryl has been mentioned 

by George F. Kunz 33 in reports on precious stones in 1885, 1892, 

1898, and 1899. The mine has been idle since 1900, and in 1914 the 

workings were covered with vegetation. The mine was formerly 

owned by S. L. Wilson and George Eoebling, but is now held solely 

by Mr. Koebling, of Northville. An examination of the deposits 

was made by the writer in October, 1914, at which time the following 

notes were taken:

32 Economic geology of the feldspar deposits of the United States: U. S. Geol. Survey 

Bull. 420, pp. 41-53, 1910.

83 Precious stones: U. S. Geol. Survey Mineral Resources, 1885, 1892, 1898, and 1899.
64 MICA DEPOSITS OF THE UNITED STATES.

The deposit is 5£ miles N. 12° W. of New Milford, or 3 miles east 

of Kent, a station on the New York, New Haven & Hartford Kailroad. The workings consist of a main cut about 120 yards longdriven southwestward into a hillside and a smaller cut (see fig. 10) 

about 100 feet south of it. The main cut ranges from 10 to 50 feet 

in depth and 30 to 40 feet wide in the northeast half. The northwest wall overhangs the workings, and the southeast wall dips 

northwestward at varying angles. A little tunnel work has been 

carried on along the hanging wall. The open cut was originally

65 feet deep toward the northeast end, but this part has been partly 

filled up by the caving of wall rock. The smaller cut is about TO feet 

long across the formations and is reached through an entrance in 

the hillside on the northeast. (See fig. 10.)

The country rock is biotite schist or gneiss, highly schistose near 

the vein, and has been mapped as Berkshire schist by Eice, Gregory, 

and Robinson.34 Through error this was reported as Becket gneiss 

by the writer in a former description of this mine. 35 The Becket 

gneiss contact as mapped lies only 100 or 200 feet east of the mine. 

Immediately around the mine the schist has a northeast strike and 

a vertical to high northwest dip. The vein rock is pegmatite, which 

ranges from 20 to 40 feet thick in the main cut. In the smaller cut 

the pegmatite is thicker but contains inclusions of schist. In the 

main cut the pegmatite strikes about parallel with the country rock, 

but to the northwest it cuts across the schistosity of the country 

rock with a lower dip. The pegmatite pinches and swells in different parts, and is reported to have been thinner near the bottom 

of the cut than at the surface. The texture of the pegmatite is extremely coarse grained. Gray quartz occurs in large massive streaks 

several feet in thickness and lies roughly parallel with the walls of 

the pegamtite; prthoclase feldspar in crystals and masses several feet 

across; and mica in bunches and pockets in different parts of the 

vein. The best mica and feldspar are reported to have come from 

the northeast half of the open cut, and the best beryl from the southwest half. Near the southwest end of the cut there are outcrops 

of quartz streaks 2 to 3 feet thick and masses of "solid mica" of 

even greater thickness, one of which is 50 feet long. This "solid 

mica" is composed of rough A and wedge-shaped crystals 1 inch to 

4 inches across, bunched closely together, and mixed with a little 

quartz and feldspar. One block of " solid mica " of irregular shape 

blasted loose from this vein measured 4 feet thick and 8 feet long. 

(See PI. X.) Such mica would be valuable only as scrap for grind84 Rice, W. N., Gregory, H. B., and Robinson, H. H., Preliminary geological map of 

Connecticut: Connecticut Geol. and Nat. Hist. Survey Bull. 7, 1907.

88 Sterrett, D. B., Precious stones: U. S. Geol. Survey Mineral Resources, 1914, p. 

313, 1916.
CONNECTICUT. 65

ing, but probably 50 tons are in sight. The mica from the northeast end of the cut yielded clear sheets several inches across, which 

were suitable for glazing. Large quantities of potash feldspar were 

sold to pottery manufacturers, and the amount realized from their 

sale paid most of the expenses of mining. Among associated minerals are a few dark-red opaque crystals of garnet, a little biotitemica, and black tourmaline.

Many crystals of beryl, some of them more than a foot in diameter, 

have been found in the quarry. In four years $17,000 worth of gem 

beryl is reported to have been sold. Mr. Roebling still has a few 

specimens showing the quality of the gem material obtained from 

the mine'.

This deposit of pegmatite or another in the same lead has been 

traced for several hundred yards across the hill southwest of the 

mine, and at a few small openings large, pure crystals of orthoclase-feldspar were seen.

Other feldspar quarries have been worked in the county but 

did not yield so much mica as the Roebling mine. During 1915 a 

specimen of mica was received at the United States Geological 

Survey from D. J. Emmons, of Canaan, near the north edge of 

the county. This crystal measured only about 3 inches across and 

had a clean, sharp, rhombic crystal outline. The color was clear 

light purplish brown with a narrow light-yellowish border parallel 

with the faces. The specimen was too small to have value, but the 

quality was such as to encourage further prospecting for larger 

sheets. Mr. Emmons carried on a little prospecting in 1915 and removed more than a ton of mica, of which 200 or 300 pounds might 

be classed as rough sheet mica.

MIDDLESEX COUNTY. 

F. E. STRICKLAND aiTAREY.

The quarry of F. E. Strickland is about 2£ miles northeast of 

Portland, in the west side of Collins Hill. At the time of examination, in October, 1914, it was operated by Mr. Strickland under 

lease to the Eureka Mining & Operating Co., of Trenton, N. J., 

all the spar, quartz, and mica going to the company. The gems 

and other minerals were retained by Mr. Strickland. The quarry 

consists of two adjoining open cuts with north and south elongation, 

parallel, and connected at the north end. The east cut is about 

300 feet long, 65 feet wide, and 10 to 40 feet deep. The west cut is 

about 200 feet long, 50 feet wide, and 25 feet deep. A crosscut 

leads out to the hillside at the north end of the west cut. (See 

fig. 11.)
66 MICA DEPOSITS OF THE UNITED STATES.

The country rock is muscovite-biotite schist and contains much 

black tourmaline near the pegmatite. It probably belongs to the 

Bolton schist as mapped by Rice, Gregory, and Robinson,30 but 

close to the contact there is a mass of Glastonbury granite gneiss. 

The schist has a general north strike and a dip of about 20° W. 

It has been warped, however, to correspond approximately with the 

contact of the pegmatite, which is a large, irregular, semibedded 

deposit both parallel with and cutting the schist in different parts. 

In the east deposit the outcrop was an elongated dome pitching

under the schist at each 

end. This body of pegmatite joins the one forming 

the west deposit under the 

surface where the two open 

cuts join at the north end. 

The geologic relations are 

shown in figure 11.

The pegmatite is coarse 

grained and contains large 

bodies of graphic granite, 

potash feldspar crystals 2 

or 3 feet across, irregular 

quartz segregations several 

feet thick, and bunches or 

streaks of mica crystals. 

Cavities or pockets with 

crystal-lined walls are 

irregularly distributed in 

parts of the quarry, especially in the east working. 

These pockets range from one of small size up to one reported to be 

4 feet long, 1£ feet wide, and 1£ feet high. Some of them have 

yielded tourmaline gems of fine quality and specimen minerals of 

interest. The gem-bearing pockets were found near the middle and 

in the south half of the east quarry. Work in this part of the quarry 

has been temporarily abandoned, but a good working face 20 feet 

high has been made across the north end of the cut preparatory to 

removing the spar. Mr. Strickland expects to find more gem pockets 

when this block of pegmatite is quarried.

Among other minerals adjoining and lining the walls of the pockets 

are coarse, flat albite or clevelandite crystals, granular lepidolite. 

rough quartz crystals, greenish muscovite crystals, and a little beryl.

89 Rice, W. N., Gregory, H. E., and Robinson, H. H., Preliminary geological map of 

Connecticut: Connecticut Geol. and Nat. Hist. Survey Bull. 7, 1917.

Biotite gneiss 

showing strike 

ana dip

1 Streak of biotite 

mica crystals

fo~| Pit zoo Feet

FIGURE 11. Plan of Strickland feldspar, mica, 

and gem quarry, 2J miles northeast of Portland, Conn.,, showing geology.
CONNECTICUT. 67

Much of the beryl is opaque and yellowish green, but in one pocket 

an irregularly shaped fragment of transparent pale salmon-pink 

beryl was found. It is 2| inches long and 1 inch thick, with an exceedingly rough honeycombed and drusy surface. It is evidently the 

remnant of a much larger crystal, most of which has been dissolved, 

leaving only a part with a rough etched surface. Portions of this 

would cut into small gems. In some of the pockets there are mossy 

tuffs or coatings of minute short hairlike tourmaline crystals of dull 

greenish-gray color. Some of these coatings cover a couple of square 

inches of the surface of albite crystals and make exceedingly delicate, pretty specimens. Gem tourmalines of fine greenish-blue, 

bluish-green, and nearly grass-green color have been obtained from 

some of the pockets.

Among other minerals found in the quarry are muscovite and 

biotite mica, columbite, and a few garnets. The mucsovite occurs 

in plates as wide as 12 inches but most of it does not have good cleavage. It is yellowish green, and where the cleavage is good the mica 

is suitable for the glazing trade. The bulk of the crystals are so injured by A lines and tangle-sheet structure as to be suitable only as 

scrap for grinding. The mica is saved during quarrying and sold 

at intervals as scrap, but that suitable for sheets is doubtless sorted 

out by the purchaser.

GILLETTE OK HADDAM NECK QTTABRY.

The M. P. Gillette or old Haddam Neck quarry is 1 mile N. 22° E. 

of Haddam, near the east bank of Connecticut River. It is one of 

the oldest quarries in Connecticut and has been worked for gem and 

specimen minerals as well as for feldspar. Mica was obtained as a 

by-product. The deposit has not been worked for several years, 

and the pits were partly filled with water and overgrown with vegetation at the time of visit in 1914. The quarry consists bf one large, 

irregularly shaped open cut about 300 feet long in a north and 

south direction and 100 feet wide at the widest part, which joins a 

smaller open cut on the west about 150 feet long in a north and south 

direction and 35 feet wide. These quarries range from 20 to 30 feet 

deep and have crosscuts leading out to two large dumps on the river 

side. One cut extends west from the west quarry and the other west 

from the south end of the east quarry. According to Bastin the 

west quarry was worked chiefly for tourmalines and specimen minerals. The east quarry was worked chiefly for feldspar, but also 

yielded mica, gem tourmalines, and specimen minerals. The shape 

of the workings and the general geologic relations are shown in 

figure 12.
68 MICA DEPOSITS OF THE UNITED STATES.

:$ . Dump

3 Dump

M u scov ite - bi ot i te 

gneiss or schist

0 50

Good 

ica streak

The country rock is dark-gray muscovite-biotite schist or gneiss, 

mapped as Monson granite gneiss by Kice, Gregory, and Robinson.87 

The gneiss strikes about north and dips vertically. The pegmatite 

is large and is divided into several streaks by large inclusions or 

horses of schist. In the north end of the quarries there are three 

beds of pegmatite having a total thickness of about 100 feet in a 

width of 150 feet. In the middle of the quarry on the south side the 

schist unconformably overlies a rounded boss of pegmatite. This 

boss pitches to the south and on the north side of the quarry outcrops

as a bed nearly 50 feet 

thick conformably between 

schist walls. The pegmatite contains large masses 

of graphic granite, potash 

feldspar crystals 1 to 3 

feet across, generally with 

a little intermixed albite, 

muscovite, black and green 

tourmaline, and pockets or 

cavities lined with crystals. 

Some of the mica crystals 

measure more than 1 foot 

across and are 6 inches 

thick, but do not split well 

because of the presence of 

wedge, A, and tangle-sheet 

structures. At the time of 

examination some mica 

crystals were found that 

measured more than 8 

inches across, but they were 

rendered unfit for anything but grinding by tangle-sheet structure 

and by the presence of many small green tourmaline crystals and 

needles both parallel with and penetrating the laminae in many 

directions. A few good mica crystals of yellowish-brown color which 

would trim into sheets 2 by 2 inches were seen.

The feldspar shipped to the pottery manufacturers is said to have 

been chiefly graphic granite or irregular intergrowths of feldspar 

and quartz with smaller quantities of nearly pure feldspar.

Most of the gems and specimen minerals are found in pockets or 

cavities. Bastin 38 describes the gem pockets in the east cut as

87 Rice, W. N., Gregory, H. E., and Robinson, H. H., Preliminary geological map 

of Connecticut: Connecticut Geol. and Nat. Hist. Survey Bull. 7, 1907.

08 Economic geology of the feldspar deposits of the United States: TJ. S. Geol. Survey 

Bull. 420, pp. 48-49, 1910.

Pegmatite, 

not quarried

300 Feet

FIGURE 12. Plan of Gillette or Haddam Neck feldspar and gem quarry, 1 mile N. 22° E. of Haddam, Conn., on east bank of Connecticut River, 

showing geology.
CONNECTICUT. 69

averaging 8 or 10 inches in diameter, though there are many smaller 

ones only 2 to 3 inches. They are distributed very irregularly 

through the mass of pegmatite. Lepidolite in finely granular masses, 

pale-green albite, and small crystals of green tourmaline are 

abundant near many of the pockets. Muscovite surrounded by a 

border of lepidolite, or in parallel growth with lepidolite, is also 

of common occurrence near the pockets. In this as in most other 

gem-bearing pegmatites, the crystals of tourmaline are seldom in 

their original positions on the walls of the cavities but lie embedded 

in a sandlike mass of quartz fragments, cookeite, and other decompo-. 

sition products at the bottom of the pockets. They are mainly grassgreen to olive-green but become nearly colorless toward the tip. The 

exact apex of some of the crystals is pink and many of them show 

very perfect terminations. Gem tourmaline is not so abundant here 

that it would pay to work the mine for this alone. Most of the gems 

found in mining for feldspar were marketed irregularly through 

local collectors.

ANDREWS QUARRY.

The Andrews quarry is about 2£ miles south of South Glastonbury and about half a mile south of the Middlesex-Hartford county 

line. It is a large quarry with a working face 25 feet high. Graphic 

granite is the principal material shipped for pottery manufacture. 

Some mica is found, but it is nearly all in crystals less than 3 inches 

in diameter and is suitable only for grinding. Other minerals 

found in the quarry are small red garnets, black tourmaline, and 

biotite-mica.

JOSEPH HALBERG QUARRIES.

Two quarries have been opened on the land of Joseph Halberg, 

a little over 1£ miles southeast of Middle Haddam, but they were 

not in operation when visited in 1914. Bastin called one of them, 

100 yards south of the house, the Eureka Mining & Operating Co.'s 

quarry, after the company operating it at that time. Besides feldspar for making pottery this quarry contains muscovite and biotite 

mica and pockets carrying gem tourmaline. The mica occurs in 

blocks from 4 to 5 inches across, a few measuring 8 inches, all of 

which was sold as scrap for grinding.

The other quarry, opened after Bastin's visit, is about 50 yards 

northeast of the house. A small quantity of scrap mica was removed during the quarrying for feldspar.

HARTFORT COUNTY. 

ROARING BROOK QUARRY.

A quarry was worked for feldspar on the south side of Roaring 

Brook valley, half a mile east of South Glastonbury. The quarry 

11137& 23 6
70 MICA DEPOSITS OF THE UNITED STATES.

is in a pegmatite mass intruded into nearly horizontal mica schist, 

probably of the Bolton schist formation. Microcline feldspar occurs in pure bodies as wide as 3 feet and quartz in opaque 

milky-white masses. Mica has been found in crystals from 4 to 6 

inches across and 6 inches thick. Most of the crystals are so badly 

ruled or crumpled that they are suitable only for s:rap. Other 

minerals of the pegmatite are biotite and garnet.

EAST GLASTONBURY QUARRY.

The East Glastonbury quarry is 2| miles northeast of South Glastonbury on the farm of Frank G. Curtis. The quarry has been 

worked to obtain feldspar for the manufacture of abrasive soaps. 

A nearly vertical dike of pegmatite cuts across biotite granite gneiss. 

The pegmatite contains cream-colored microcline feldspar in pure 

masses from 2 to 3 feet across. Quartz is not found here in large 

masses. Mica is fairly plentiful but most of it is in crystals less than 

3 inches across. A few crystals measure 5 or 6 inches. Most of the 

mica is in wedge-shaped or twinned crystals and is suitable only for 

grinding.

WIARDA AND HOWE QUARRIES.

A little mica, chiefly in small crystals, is found in the feldspar 

quarries of the John C. Wiarda Co., 1£ miles south of South Glastonbury, and of Lewis W. Howe, 2 miles south of South Glastonbury. Most of this mica is in wedge-shaped crystals or has the A 

structure so strongly developed that it is suitable only for grinding.

NEAV HAVEN COUNTY. 

SOUTHFORD QUARRY.

The Southford quarry is about If miles south of the station bearing that name. It is worked by the Bridgeport Wood Finishing Co.. 

for quartz but yields some feldspar and mica. Quartz makes up a. 

larger proportion of the rock than usual in the pegmatites of Connecticut. Mica is rather plentiful. It occurs chiefly in bladelike or 

spearhead-shaped crystals. Some of these crystals are 1£ feet long 

and 6 inches across. No sheet mica is obtained, and all the product 

is sold as scrap for grinding.

GEORGIA.

GENERAL FEATURES.

Mica-bearing pegmatites have been found in 20 or more counties 

of Georgia. A small amount of test work has been done at many 

of the prospects, but mining has been carried on at a few places only
GEOEGIA. 71

and has never become a regular industry. The distribution of the 

deposits and the occurrence of the mica have been described in detail 

by S. L. Galpin.89 Much of the information given below has been 

abstracted from Galpin's report, but a few of the mine descriptions 

have been prepared in part or wholly from notes made by the writer 

during brief visits to the deposits in 1908 and 1914.

Galpin considers the following the only counties likely to become 

producers of mica: Carroll, Cherokee, Elbert, Hall, Hart, Henry, 

Lumpkin, Meriwether, Monroe, Oconee, Paulding, Pickens, Rabun, 

Talbot, Troup, Union and Upson. Of these, the deposits of 

Cherokee, Elbert, Hart, Lumpkin, Rabun, and Union are the mostpromising. Most of the deposits are in the Piedmont Plateau 

region, but a few are in the rough mountain section in the northeastern part of the State, especially those in Lumpkin, Rabun, and 

Union counties.

The deposits are associated chiefly with pre-Cambrian rocks (the 

Carolina gneiss and the Roan gneiss of Keith), but a few deposits 

in Pickens County are with rocks of later age, probably CambrianGranitic rocks are present in many of the regions where mica 

deposits occur. Some are early or pre-Cambrian intrusions and 

others are of later or post-Cambrian age. The location of the 

deposits and the general geology of the mica region are given in the 

accompanying map, reproduced from S. L. Galpin's report by permission of Dr. S. W. McCallie, State geologist of Georgia. (See PI. 

XI.)

The surface rock over most of the region' has been deeply weathered 

and fairly fresh outcrops of pegmatite and the inclosing rocks are 

found only where the valleys have been cut through the mantle of 

residual soil. In the uplands the outcrops of pegmatite are marked by 

kaolin (white where not discolored by other products of weathering) 

containing more or less clay-stained mica and blocks or boulders of 

quartz scattered over the surface. When the upland deposits are 

opened weathering extends to varying depths, even exceeding 50 feet.

CARROLL COUNTY.

Crystals of mica 4 to 6 inches across have been found in a 10- 

foot bod}' of pegmatite on the land o>f J. A. Po.tate, 1-J miles north of 

Temple. The vein outcrops for 150 yards across a small gully. The 

feldspar^ has been kaolinized, and the mica has been rather badly 

ruled. Deposits 1 mile to 3 miles northwest of Burwell were 

also examined, some of which contained mica plates 3 by 4 inches.

m A preliminary report on the feldspar and mica deposits of Georgia : Georgia Geol. 

Survey Bull. 30, 1915.
72 MICA DEPOSITS OF THE UNITED STATES.

CHEROKEE COUNTY.

The principal mica deposits of Cherokee County occur in a belt 

about 3 miles wide that enters the southern border of the county 

west of Woodstock and extends northeastward through the Hollysprings-Toonigh region to and beyond Hickory Flat to Lathantown. 

Starting in the southwestern part of the belt, deposits belonging to 

the following persons were examined by the writer: De Lay brothers, 

M. M. Cole, J. B. Wheeler, and W. J. Cook. Mr. Galpin also examined the property of J. D. Hillhouse, the old Dean mica mine, 

and prospects near Lathantown, all of which are described elsewhere 

in this bulletin.

DE LAY PROSPECT.

About 100 pounds of mica was taken out of a pit on the land of the 

De Lay brothers, 3 miles west of Woodstock. The pit was only 4 feet 

deep and was made in one of three outcrops in a field. Much of 

this mica had the A structure and part was specked. Good sheets 

could be cut from the material between the A lines, where the cleavage was smooth in some of the crystals. The largest crystals seen 

with the A structure were 8 to 10 inches long and one of them would 

have yielded plates 1^ by 4 inches. The mica occurs in pockets along 

the side of a quartz vein in a pegmatite several feet thick. The pegmatite is inclosed in mica gneiss that has a northeast strike.

OLD DEAN MICA MINE.

The old Dean mica mine, about 3^ miles northwest of Woodstock, 

has not been worked since 1889. It is now owned by C. W. Flentke, 

of Evansville, Ind. The mica obtained from this mine is reported to 

have been ground on the property. The mine was worked chiefly 

through two open cuts, one extending across the formation into a 

hillside and entering another about 75 feet long, 30 feet wide, and 25 

feet deep, which follows the " mica lead." A short tunnel extends 

northeastward from the bottom of the cut. Two masses of pegmatite 

striking N. 40° E. and dipping southeast were exposed in the cut. 

One of these masses 3 to 4 feet thick, which lies along the west side 

of the working face, contains partly decomposed feldspar, a little 

quartz, and mica in crystals as much as 3 to 4 inches across. 

The mica crystals occur in a streak about a foot thick along 

the hanging wall, where they form possibly 20 to 25 per cent of the 

rock. The crystals are ruled and have been badly stained with clay. 

The other mass of pegmatite, which is more than 10 feet southeast of 

the first, is 10 feet thick in the bottom but pinches toward the top of 

the cut. The feldspar content of this pegmatite has been kaolinized. 

A streak about 2 feet thick near the hanging wall carries mica crys-
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XI

N 0 R T H

____ __ _______

E S S E E A R 0 L i N A

MAP OF NORTHERN GEORGIA SHOWING LOCATION OF MICA AND FELDSPAR DEPOSITS

After S. L. Galpin

Scale TooSooo

3D __ 20 _____ 3O so EloiQ.elei>ri
GEORGIA. 73

tals, none of which as exposed measured more than 3 inches across. 

Galpin describes as "mica conglomerate" a mixture of mica and 

quartz from which a little feldspar has been dissolved in smaller 

pegmatites on the hill above the mine. This material would probably be called "mica capping" in the mica regions of North Carolina.

J. D. HILLHOUSE MINE.

Galpin mentions several prospects opened on the J. D. Hillhouse 

place, 1£ miles west by north of Toonigh. The prospects are on 

or near the crest of a low ridge. Several bodies of pegmatites were 

opened within a belt/ 100 yards wide. At least one of these bodies 

is 8 to 12 feet thick, but the others are thinner. Mica crystals measuring 3 or 4 inches across were found in irregular streaks along the 

walls of some of the masses of pegmatites. The mica has good cleavage but is specked with magnetite. The feldspar of the pegmatites 

has been almost entirely kaolinized.

M. M. COLE PROSPECTS.

Mica prospects have been opened on the M. M. Cole place, 1£ miles 

N. 25° W. of Toonigh. Most of the work was done by Charles Makepeace, of Ball Ground, Ga. The prospects occur in a series of outcrops of pegmatite within a distance of about 350 yards in a direction N. 30° E. along the summit and east side of a ridge. The relief between the ridge and the stream to the southeast is about 50 

feet. The largest working is at the northeast end of the outcrops 

in the hillside, a few feet above the stream, where two tunnels 30 feet 

apart were driven west into the hillside and curved in the shape of 

a horseshoe so as to meet each other at a distance of about 50 feet. 

The country rock is mica gneiss. The pegmatite cuts the gneiss irregularly, branching from a large deposit on the southwest side into 

smaller streaks in the workings. The mica was found rather irregularly in bunches or pockets in the decomposed pegmatite.

Most of the mica is specked, some rather heavily, with thin films 

of magnetite between the laminae. The cleavage is good, and a little 

clear mica is obtained by splitting many of the crystals. Several 

tons of mica suitable for small sheets, punch, and scrap was left 

on the dump.

J. B. WHEELER PROSPECT.

Several prospect pits and a shaft were opened about 1890 on the 

land of J. B. Wheeler, 2 miles east of Holly Springs. The pits rail 

within a distance of 75 feet in a N. 35° E. direction. The shaft is 25 

feet deep and lies southeast of the line of pits and the pegmatite. 

The country rock is mica gneiss which strikes about northeast and
74 MICA DEPOSITS OF THE UNITED STATES.

Ho

dips almost vertically. The body of pegmatite is approximately 

conformable with the gneiss and is 6 or more feet thick. Little could 

be seen in the workings, but on the dump weathered mica ranging 

from minute scales to crystals 5 or 6 inches in diameter were seen. 

The mica is clear and light in color.

In a field a quarter of a mile west of this prospect many A and 

wedge shaped crystals of mica were plowed up.

coos MINE.

The W. J. Cook mine is 8 miles S. 80° E. of Canton, or a little more 

than 2 miles south by west of Orange. The mine was worked by the 

Pittsburgh Mica Mining Co. in 1907, Mr. Cook acting as superintendent, but later the property passed to Mr. Cook. The equipment 

consisted of a 25-horsepower gasolene engine and a dynamo to generate current for mine use, a hoist operated by a 7-horsepower electric motor, mine cars, 

and track, and electric 

lights. The workings 

consist of an incline 

reported to be 150 feet 

deep, a drift extending 

'<s$V#??££/N?rt from the incline 70 feet 

long in a N. 30° E. 

direction at about the 

30-foot level, an interior shaft 30 feet 

deep on the southeast 

side of the drift, an 

incline 20 feet deep at 

the northeast end of the drift, an upraise connecting with a shaft 

from the surface and used as an air shaft, a shaft 22 feet deep connected with the 70-foot drift by a short incline, short drifts from this 

shaft at a depth of about 15 feet, and two surface pits. The position 

of the different workings are shown in figure 13. The interior shaft 

and the incline below the 70-foot drift were filled with water at the 

time of examination. The mouth of the incline had caved in, and 

entrance to the workings was made through the 22-foot shaft.

The country rock is mica gneiss cut by pegmatite and pegmatitic granite. The pegmatite bodies are approximately conformable 

with the inclosing gneiss but cut across it in places. The formations 

strike about northeast and dip 45° SE. The pegmatite is somewhat 

irregular in shape and branches out from the main mass. It varies 

in thickness from less than a foot in some of its branches to 8 or 

10 feet where opened by the pits and the 22-foot shaft. The " vein " 

was much thinner in the 70-foot drift than above and ranged from

(inter/or)

'' ' :' : '. " '.' ';V;:':' 0 25 50 100 Feet

FIGURE 13. Plan of W. J. Cook mine, 8 miles S. 80 

of Canton, Cherokee County, Ga.
GEORGIA. 75

a few inches to 3 feet. The pegmatite was richest in mica in the 

upper workings and did not yield much at the 70-foot drift or lower. 

The deep incline yielded practically no mica but was sunk chiefly 

in the mica gneiss country r'ock. The feldspar of the pegmatite is 

kaolinized in the upper workings but was only slightly altered below the 70-foot drift.

Pegmatitic quartz containing a few boulders of pegmatitic granite 

and pegmatite, both carrying mica crystals ranging from a fraction 

of an inch to 2 inches in diameter, are scattered over the surface 

of the ridge for a distance of about 300 yards to the northeast. None 

of these pegmatite outcrops have been tested for mica.

Mr. Cook states that about 4,500 pounds of mica trimmed into 

sizes ranging from punch to 5 by 7 inches was shipped to Pittsburgh. Several tons of scrap and mica suitable for punching or 

small sheets was left at the mine. The mica is rum-colored, and 

part of it contains numerous small specks. The cleavage is smooth 

and flat.

Other mica prospects have been found in Cherokee County but 

have not proved promising when opened. At one of these, on the 

David Bennett place, several miles west of Nelson, Galpin found a 

pegmatite 1 foot to 4 feet thick exposed in several shallow pits and 

trenches along a ridge. The pegmatite follows the ridge and strikes 

N. 40° E. No recent work had been done, but a little mica was 

found in the pegmatite and around the workings. It is of good 

quality, but the largest seen would not trim to sheets of more than 

2 by 4 inches.

ELBERT COUNTY.

CHAPMAN MINE.

The mica deposits of Elbert County occur chiefly in the northeastern part. Prospecting and mining have been carried on during several periods at the J. E. Chapman place near the junction of Eocky 

Branch and Coldwater creeks, the most extensive work being done 

in 1907 and in 1910. At the main working a drift was run 200 feet 

diagonally into the hillside to connect with a crosscut tunnel. The 

pegmatite and inclosing mica gneiss strike northeast and dip almost 

vertically. The " vein " is about 7 feet thick and has been rather 

strongly weathered. About 15 tons of mica is reported to have been 

shipped. Sheets left around the mine have a good cleavage but are 

rather heavily specked.

About a quarter of a mile north of the main working an open cut 

exposes a large pegmatite inclosing irregular quartz segregations. 

Masses of wedge, A, and herringbone mica are thickly packed around 

the bodies of quartz. No sheet mica was observed by Galpin at this 

prospect.
76 MICA DEPOSITS OF THE UNITED STATES.

HALL COUNTY. 

HOPE MINE.

The George M. Hope mine is about 1£ miles west by north of 

Gainesville. The followi!?" description and sketch map are reproduced from a report by S. I Galpin, supplemented by a few notes 

taken by the writer during a brief visit in November, 1914. The 

workings consist of numerous pits, cuts, shafts, tunnels, and inclines 

extending from a branch on the south for more than 100 yards northward along the west side of a small hollow. Most of them have 

caved in badly, so that the formations were exposed in only a few 

places. The position of the workings is shown in figure 14.

Contour interval 10 feet

FIGURE 14. Sketch map of Hope mica mine near Gainesville, Hall County, Ga. (After 

S. L. Galpin.) 1. Shaft 120 feet deep; 2, shaft badly caved; 3, incline to shaft; 4 

and 5, 20 to 30-foot inclines; 6, 7, 8, and 9, shafts; 10, 40-foot incline; 11, 60-foot 

incline; 12, 40-foot tunnel exposing 12-foot kaolinized pegmatite; 13, partly caved 

incline extending to open cut, 14; 15, recent prospect; 16, open cut and tunnel; 17, 

long open cut; 18, dump; 19, storage house; crossed hammers, minor prospects.

The country rock is coarse mica schist, garnetiferous in places, 

with a few streaks of inclosed hornblende gneiss. The strike in the 

vicinity of the mine ranges from due north to N. 30° W. and the 

dip from 25° to 50° west and southwest. Several pegmatites have 

been opened in mining. Three mentioned by Galpin are in part 

conformable with the inclosing schist and in part cut across its foliation. They range in thickness from a foot or two to 16 feet. In the 

incline at 5 (see fig. 14) the pegmatite is about 5 feet thick and carries 

a good mica content. At 13 the pegmatite is about 8 feet thick, but 

the mica content of that exposed at the time of examination was low. 

Most of the feldspar in the upper workings was kaolinized, but nearly 

fresh potash feldspar occurs near the level of the branch. An analysis 

of feldspar from the prospect at 15, by Edgar Everhart, showed 10.02 

per cent potash, 1.25 per cent soda, 21 per cent alumina, 1.2 per cent
GEORGIA. ' 77

ferric oxide, and 59.87 per cent silica. The mica has smooth cleavage 

and a clear light rum color. Only small sheets and scrap were 

seen around the mine, but good sizes are reported to have been found. 

Galpin suggests that possibly the kaolin associated with the mica 

might be profitably washed and says that a good location for a washing plant can be found.

None of the mica deposits in the' counties mentioned below have 

been visited by the writer, and all information regarding them has 

been abstracted from S. L. Galpin's report.

HART COUNTY.

The following mica deposits in Hart County have been described 

by Galpin:

CRAFT PROSPECT.

A prospect shaft 12 feet deep was opened on the J. W. Craft 

farm in the southeast6rn part of the county. The pegmatite is nearly 

8 feet thick and incloses several quartz streaks or veins. About 2 

tons of rough thumb-trimmed mica was reported to have been taken 

from the prospect. A quantity of A and partly clay-stained mica 

was left around the pit. Other prospects have been opened on adjoining farms.

HEATON PROSPECTS.

Two prospects on separate bodies of pegmatites about 200 yards 

apart have been opened on the J. S. Heaton farm, 1 mile south of 

Hartwell. Clay-stained mica of good quality and with good cleavage 

was found in both prospects.

HAILEY PROSPECT.

Mica-bearing pegmatite outcrops at several places on the J. A. 

Hailey estate, 3£ miles southwest of Hartwell. Mica ranging from 

thin films to plates 3 by 5 inches are scattered over a field in line with 

one of the larger outcrops. A few beryl crystals have also been 

found on this place.

HODGES PROSPECT.

Several small open cuts and pits were made on the W. L. Hodges 

farm, 1 mile north of Hartwell. Mica of good quality but in small 

sheets was found in decomposed pegmatite.

EVANS PROSPECT.

Two prospects were opened on the B. W. Evans place. Very little 

mica had been left around one of these prospects near the public road, 

but a quantity of small mica and clay-stained sheets wjas found 

around the other one.
78 MICA DEPOSITS OF THE UNITED STATES.

PARHAM PROSPECT.

A little prospecting on the Earl Parham place, 5 miles northeast 

of Hartwell, exposed two thin flat-lying bodies of pegmatite. The 

upper one of these bodies contains a mass or pocket of tangled herringbone mica, some of the crystals of which are 10 inches long, and 

a little good-splitting mica.

WILLIAMSON PROSPECTS.

Three pits and two hillside trenches have been opened on the J. B. 

Williamson place, 2-| miles south of Air Line. The country rock is 

staurolite and garnet schist. A body of pegmatite 3 to 15 feet thick 

cuts it with a strike of about N. TO 0 E. and a dip of 60° SE. The 

mica occurs along the hanging wall but is so badly weathered that 

probably no use can be found for any material taken above the 

water level.

MORRIS PROSPECT.

T. E. Morris has prospected for mica on the Tribble place, the 

mineral rights of which he holds, 2£ miles north of Air Line. 

Several hundred pounds of clear rum-colored mica with good cleavage but somewhat clay stained was obtained from a 15-foot trench 

on a thin pegmatite.

Other prospects are known, especially within 5 miles of Hartwell, 

but extensive clay staining of all mica mined above water level in 

Hart County has materially affected its commercial value.

LUMPKIN AND UNION COUNTIES. 

LOCATION OF DEPOSITS.

A number of deposits of pegmatites have been prospected or 

worked for mica in the Tworun and Yahoola districts of Lumpkin 

County and in the Gaddistown district, adjoining them on the north 

in Union County. The deposits are on both sides and along the 

summit of the Blue Ridge Mountains, the crest of which forms the 

boundary line between the two counties. Some of the deposits were 

briefly described by the writer in 1908,40 but a more complete description of the region and mines has been given by Galpin, from 

whose report the following descriptions have been taken, supplemented by notes of the writer. The mines are from 8 to 15 miles 

north and northwest of Dahlonega, and the location of the deposits 

is shown in figure 15 (reproduced with slight changes from Galpin's 

report). Eight or more of these deposits were worked by the Pitner 

Mica Co. between 1898 and 1908, but little work has been done since 

that time.

«° Sterr«tt, D. B., Mica: U. S. Geol. Survey Mineral Resources, 1908, pt. 2, pp. 743-754, 

1909.
GEORGIA. 

SAIN MINE.

79

The Sain mine of the Pitner Mica Co. is about 2^ miles south of 

Cooper Gap and about 1 mile northwest of the old Tworun post 

office. It was opened by a 60-foot incline equipped with a hand 

hoist. The country rock is mica gneiss interbedded with a little 

hornblende gneiss. The body of pegmatite seen by the writer is 

very irregular in shape and is reported to range from 2 to 10 feet 

in thickness. It carries horses or inclusions of the mica gneiss and

84*00'

Contour interval 500 feet

FIGURE 15. Sketch map of parts of Lumpkin and Union counties, Ga., showing the 

location of the principal mica mines and prospects. Topography taken from U. S. 

Geol. Survey maps of Ellijay and Dahlonega quadrangles. 1, Jones Creek prospect; 

2, Sain mine; 3, Williams mine; 4, Ward mine; 5, Masters or Geddes mine; 5-A, 

Graham mine; 6, Henry Lee mine; 7, Eph Lee mine; 8, Ward Gap mine; 9, Green 

Vein mine; 10, Long Mountain mine; 11, William Gooch mine; 12, mica mill; 13, 

Thomason prospect; 14, Gooch mine; 15, Scott mine; 16 and 17, Cassity prospect; 

18, Caldwell prospect; 19, Wash Walker or Big mine; 20, Wess Walker mine. Other 

less important or unnamed prospects and mines are represented by crosses.

hornblende gneiss. Several tons of mica was found in pockets 

within a few feet of the surface. Some of the crystals were 15 to 

18 inches across but were cut into smaller plates by ruling. The 

mica has a rum color but is clay stained from surface weathering.

WILLIAMS MINE.

The Williams mine of the Pitner Mica Co. is about 250 yards 

northeast of the Sain mine. It was opened by an incline 120 feet 

deep with a hand hoist, skips, drills, and other equipment. The
80 MICA DEPOSITS OF THE UNITED STATES.

country rock is mica gneiss which strikes northeast and dips southwest. Galpin found a mass of pegmatite, 6 to 15 feet thick, striking 

N. 10°-20° E. and dipping southwestward when the mine was cleaned 

out in 1913. The portion of the " vein " examined by the writer in 

1908 appeared to strike northwest and dip 20° NE., cutting across 

the bedding of the gneiss. The vein is composed of partly decomposed feldspar through which are scattered lenslike masses of quartz. 

Mica crystals occur along the feldspar^quartz contacts wholly or 

partly inclosed in either mineral. Vugs found in some of the quartz, 

lenses contain smoky and clear quartz crystals, and Mr. L. M. Richard, 

of Stamford, Tex., found a colorless topaz crystal in a cavity in a 

mica crystal during 1913. Mica crystals as much as 18 inches across 

were seen in 1908, and Galpin mentions one more than 2| feet across 

exposed in the roof of the incline. The mica is strongly ruled, and 

much of it is in A-shaped crystals. The thicker sheets have a greenish 

cast.

WARD MINE.

The Ward mine is about 2 miles south of Cooper Gap 300 yards 

west of the road to Dahlonega. It was opened by a trench 40 feet 

long with tunnels, now badly caved in, at each end and a short incline on the " vein " near the southwest end of the trench. A small 

pegmatite with a 60° SE. dip was poorly exposed in the workings. 

Only small mica was left around the prospect, but this was of good 

quality.

MASTERS OR GADDIS MINE.

The Masters or Gaddis mine of the Pitner Mica Co. is a little 

more than half a mile east of the Sain mine. It was worked by a 

40-foot open cut, a 40-foot shaft, and a 20-foot incline. A tunnel 

at a lower level has caved in. The country rock is kyanitic mica 

gneiss with variable strike and dip. The pegmatite occurs in lenses, 

more or less connected, and ranges in thickness from a few inches 

to several feet. The main lead of lenses has been traced northeast 

for about 75 yards. Branch " veins " or lenses of pegmatite occur on 

the northwest side of the main lead and contain some good mica. 

Sheet mica and a quantity of ruled and A mica were obtained from 

the workings.

GRAHAM MINE.

The Graham mine is about one-fifth of a mile south of the Masters 

or Gaddis mine. The pegmatite has a strike of N. 60° E. and a vertical to southeast dip. It contains a quartz streak or lens 30 feet long 

and from a fraction of an inch to 2 feet thick parallel to its strike. 

The pegmatite is 10 feet thick where exposed in one opening. A 

branch streak of pegmatite to the northwest is exposed at this point.
GEORGIA. 81 

HENRY LEE MINE.

The Henry Lee mine is in a prominent mountain ridge or spur 

extending south from the Blue Ridge between Cooper Gap and 

Ward Gap. It was worked by a Mr. Ashley from 1903 to 1906, but 

is now owned by the Eoland Lumber Co. Large dumps were thrown 

out, but little could be seen of the workings or formations at the time 

of Galpin's visit. The mine is reported to have yielded a large 

quantity of mica, the best of which was ribbon mica measuring 4 

by 10 inches.

EPH LEE MINE.

The Eph Lee mine is a little north of the crest of the 'Blue Ridge 

and about three-eighths of a mile northwest of Ward Gap. The 

workings consist of an irregular-shaped pit from which a tunnel 

has been driven 40 feet to. the northeast along the strike of the pegmatite. The country rock is granitic mica gneiss strongly folded and 

contorted. The pegmatite cuts the gneiss near the axis of one of the 

folds. It is 6 inches to 3 or 4 feet thick and incloses quartz veins 

or stringers. Small mica crystals 2 to 3 inches across are plentiful, 

and a few crystals 6 to 8 inches across are reported to have been 

found. The mica has a rum color, but much of it is A or has been 

crushed.

WARD GAP MINE.

This mine is in Ward Gap close to the Lumpkin-Union county line. 

The workings consist of an irregular open cut, with a crooked incline 

extending a few feet into the south wall. The pegmatite is at least 

6 feet thick and cuts the mica gneiss country rock unconformably. 

It contains both granular quartz and small lenses and masses of 

quartz. The mica is associated with the quartz masses: It is rumcolored to smoky brown, and a rather large proportion is of the A 

variety. Mr. J. L. Ingram, who operated the mine for the Pitner 

Mica Co., reports that he removed about 3 tons of rough sheet mica 

and much scrap mica, some of which was ground at the company's 

mill, about 2 miles northeast of the mine. Mining cost about 50 

cents a 100 pounds for scrap and about 75 cents a 100 pounds for 

rough sheet for trimming. A day's work yielded from 100 to 600 

pounds of mica.

GREEN VEIN MINE.

The Green Vein mine is in the south side of the Blue Ridge Mountains about three-eighths of a mile southeast of Ward Gap. As seen 

by the writer it was opened by a cut 20 feet deep and 40 feet back 

into the mountain side. Galpin mentions two other pits probably 

below this. The country rock is mica gneiss with a northerly 

strike and 30° E. dip. The mass of pegmatite, ranging from 1 foot
82 MICA DEPOSITS OF THE UNITED STATES.

to 5 feet in thickness, cuts across the country rock with the same 

strike and a nearly vertical dip. The " vein " contains both granular 

and massive quartz segregations. Only small mica was seen. This 

has a strong green color in thick sheets but is practically colorless 

when split into thin sheets. Galpin states that the color seems to 

be due, in part at least, to inclusions of darker mica, probably biotite. 

Four tons of thumb-trimmed and a quantity of scrap mica are reported to have been taken from the Green Vein mine.

LONG MOUNTAIN MINE.

The Long Mountain mine of the Pitner Mica Co., is a little west 

of the summit of Long Mountain and about two-thirds of a mile 

northeast of Ward Gap. It was opened by a trench 25 feet long, 

now badly caved in. A pegmatite 4 feet thick was exposed striking 

N. 20° E. and dipping southeast. The "vein" consists of kaolinized feldspar, quartz, and a little mica. Much A mica was left on 

the dumps, but 5 or 6 tons of rough-trimming mica of good quality 

is reported to have been obtained in a few days' work.

THOMASON MINE.

The Thomason mine is about a mile east of Gaddistown. It was 

worked by an open cut and a short incline on a pegmatite about 2 

feet thick. The vein strikes N. 20° W. and dips 45° NE. Only A 

mica suitable for grinding was found.

MATT GOOCH MINE.

The Matt Gooch mine is about a quarter of a mile north of the 

Thomason mine. It was opened by a trench and a tunnel 50 feet 

long on a pegmatite 3 to 6 feet thick. The pegmatite has a north 

strike and low west dip. It contains irregular quartz masses and 

segregations with which the mica is associated. The mica has a dark 

color, and part of it is specked with magnetite.

OLD SCOTT MINE.

The Old Scott mica mine of the Pitner Mica Co. is 10£ miles north 

of Dahlonega and 30 yards west of the road leading to Grassy Gap. 

It has been worked intermittently for more than 30 years. The 

workings consist of a large open pit with entry trench and several 

short inclines on the dip of the " vein." The pegmatite is 6 feet thick 

and contains irregular quartz segregations. Both A and clear, flat, 

splitting mica were mined. Other prospects were tested by the 

Pitner Mica Co. on the Cassity and Caldwell farms south and northeast of the Old Scott mine.
GEORGIA. 83 

WASH WALKER OR BIG MINE.

The Wash Walker or Big mine of the Pitner Mica Co. is a little 

more than 2£ miles northwest of Porter Springs. Two nearly parallel 

drifts only a few feet apart and at slightly different levels were made 

on two pegmatites that join a short distance to the southwest. The 

pegmatites strike northeast and dip southeast, cutting the bedding of 

the gneiss, which strikes west of north and dips northeast. Mica 

of good quality and some of the A variety were found.

J. W. WALKER PROSPECTS.

Two prospects have been opened on the J. W. Walker place, 2-| 

miles northwest of Porter Springs. One is a quarter of a mile north 

of the Walker house and the other is a quarter of a mile east of the 

house. At the north .prospect the pegmatite cuts biotite-mica gneiss 

unconformably. It ranges from 3 to 15 feet thick and incloses a 

quartz mass in the thickest part. The mica came from around the 

quartz segregation. Two men working 2 weeks mined 4,000 pounds 

of mica from this deposit.

At the east prospect a 3-foot pegmatite was opened by a drift 35 

feet long. The pegmatite cuts the foliation of the gneiss with a 

strike of N. 20° E. and is banded with feldspar streaks along the 

walls and quartz with mica in the middle. The quartz contains open 

cavities or vugs. Both A and sheet mica were obtained.

A mica prospect was opened by B. E. Dyer near Tower, Union 

County, in 1908, by a tunnel driven 125 feet into a hillside. Promising samples of clay-stained mica crystals 8 to 10 inches across were 

obtained.

PAULDING COUNTY.

Mica prospects have been opened on the land of Dr. E. W. Dean, 

three-eighths of a mile south west of Hiram, on the property of M. J. 

Petty, a quarter of a mile northeast of the Dean prospect, and on 

the Turner farm, 5 miles north of Da1 las. At the Dean prospect 

a quantity of clay-stained mica was left on the dumps, some of it 

clear sheet material but a large part of it has the A structure. Some 

of the sheets were 6 to 8 inches across. At the Petty prospect a 

pegmatite inclosing quartz lenses was opened by a 60-foot trench. 

Most of the mica seen was small and of the A variety. At the Turner 

prospect the work was directed about large quartz masses. Some A 

mica had been left on the surface.

PICKENS COUNTY.

Mica of probable value has been found in pegmatites and in the 

form of sericite schist in Pickens County. The mica-bearing pegma-
84 MICA DEPOSITS OF THE UNITED STATES.

tites occur chiefly in two belts, one 5 miles west of Nelson and the 

other 2 miles east of Nelson. In the belt west of Nelson prospects 

were opened on the F. M. Cagle farm, 5 miles west of Nelson, and on 

the Marion Davis farm, 4| miles south by west of Jasper. Trimmed 

sheets of good) quality measuring 4 by 10 inches are reported to 

have been obtained from the Cagle prospect. At the Davis prospect 

the showing is better for feldspar than for mica. Prospects were 

opened on the Burgess Fowler and John Freeman farms, 2 miles 

west of Nelson, a number of years ago. A ton or more of mica 

still remains around the pits. Most of it is badly weathered, but 

some of the crystals measure 6 to 8 inches across.

A sericite schist of remarkable purity has been found on several 

properties about 5 miles southwest of Jasper. It has been described 

by Oliver B. Hopkins 41 and S. L. Galpin, and additional notes have 

been supplied to the State geologist, Dr. S. W. McCallie, by Henderson Hallman, of Atlanta. Prospects have been tested on the 

property of Gabriel Martin, o£ miles southwest of Jasper; on that 

of J; W. Alfred, adjoining it on the east; on that of W. K. Padgett, 

1 mile northwest of the Martin Jand; and on that of William 

Richards, north of the Alfred property. The deposits consist of 

beds or layers 2 to 10 feet thick interbedded with or grading into 

quartz sericite schist of less purity.

The sericite schist is a silvery greenish-gray rock with rather close 

texture and fine slaty to schistose cleavage. It can be cut and sawed 

very much like talc, and at first was sold as talc. In its purer phases 

it is composed almost entirely of fine, flat scales of muscovite or 

sericite mica. The cleavage planes show two sets of fine folds of 

different intensity, crossing each other at large angles. Analyses 

made by the Geological Survey of Georgia show a composition quite 

similar to that of muscovite, one analysis indicating about the following percentage: Si02 , 46.75; A12O3 , 34.94; total iron oxides, 3.04; 

K2 0,10.31 ;H2 0,3.18.

The rock crushes rather easily, breaking down into fine mica scales 

resembling ground mica, and it is reported that a quantity has been 

tried as a substitute for ground mica in the manufacture of wall 

.paper, rubber and electrical goods, and for tire lubrication. Because 

of its high potash content (more than 10 per cent) experiments have 

been conducted with a view to using the sericite schist as a source of 

potash. Some of the processes of extraction are designed to save 

the alumina at the same time.

41 Asbestos, talc, and soapstone deposits of Georgia: Georgia Geol. Survey Bull. 29, 

p. 304, 1914.
GEORGIA. 85 

RABTJN COUNTY.

The best mica deposits in Rabun County have been found in a 

belt passing 6 to 10 miles east of Clayton. A number of these have 

been described by Galpin, from whose report the following descriptions have been abstracted:

McCRACKEN MINE.

The McCracken mine is 12 miles southeast of Clayton in lot 67, 

fourth district. It was worked by a number of pits, shallow shafts, 

and trenchlike open cuts. Some of the workings expose a coarsegrained pegmatite 4 to 6 feet wide, striking N. 5° E., dipping 80° E., 

and composed of pinkish feldspar, quartz, and greenish muscovite 

mica. The mica is clean and free from injurious structures.

TUNNEL MINE.

The tunnel mine is about 9 miles east of Clayton, near the top of 

the divide between Hicks and War woman creeks and not far from 

the southern entrance of a tunnel which the Blue Ridge Railroad 

Co. started a number of years ago. The workings consist of an 

open cut 100 feet long, 20 feet wide, and 30 feet deep. The country 

rock is hornblende gneiss. The pegmatite body cuts northward across 

the country rock and dips 53° E. It is 12 to 16 feet thick and coarsegrained through the main mass, but it consists of a finer-grained 

mixture of quartz and mica for a thickness of 3 feet along the hanging wall. The coarse-grained portion of the pegmatite is composed 

of partly kaolinized feldspar, graphic granite, quartz masses, and 

mica in irregular streaks through the decomposed feldspar. The 

mica is clear in thin sheets but of dark rum color in thicker sheets, 

some having the A structure.

BECK MINE.

The Beck mine was examined by the writer in 1907. It was opened 

by a cut about 100 feet long and 10 to 15 feet deep with three entries 

from the downhill side. The country rock is mica gneiss, which 

strikes N. 70° E. arid dips 25° N. Small inclusions of hornblende 

gneiss occur in the mica gneiss, and the mica gneiss has local variations of dip and strike around these inclusions. The body of pegmatite is 6 to 12 feet thick and cuts northward across the gneiss. 

A streak of massive quartz is inclosed in the pegmatite, and fragments of rough quartz crystals were thrown on the dump. A number of mica crystals 6 to 8 inches across were seen on the dump and 

in the pegmatite. Most of the mica is of the A variety, but good 

sheets could be cut from some of the crystals between the A lines. 

Bluish, bluish-green, and yellowish-green beryl crystals were found. 

111375 23 7
86 MICA DEPOSITS OF THE UNITED STATES.

Some of these measure several inches across and, though badly 

flawed, contained small clear portions. Masses of potash feldspar 

a foot across were seen in the walls of the cut.

KELL MINE.

The Kell mine is about 12 miles by road or trail east by north of 

Clayton. It was opened by a cut 60 feet long and 16 feet wide at 

the southwest base of a steep ridge a few feet above a small stream. 

The pegmatite has a maximum thickness of 24 feet, 8 to 12 feet of 

which along the hanging wall is very coarse grained. Masses of 

rose quartz and mica occur in this portion. The rest of the vein 

is finer textured. Good sheet mica is reported to have been found, 

and a quantity of A mica, which was not shipped.

Other prospects have been opened in this belt, especially in the 

region of Pine Mountain, where only a small amount of work was 

done, near Dillards, and at Mountain City.

TALBOT COUNTY.

Mica prospects have been opened on.the old Martin place, 6 miles 

east of Woodland on the Thomaston road, in Talbot County. Several barrels of sheet mica is reported to have been shipped, and only 

scrap mica was left around the workings.

TROUP COUNTY.

Mica-bearing pegmatites are rather plentiful in the northwestern 

half of Troup County. Some of the deposits 2 to 5 miles northwest 

of La Grange are reported to have yielded.good specimens of mica. 

A crystal 3 by 5£ inches was found on the Virgil E. Davis farm, 3-| 

miles west of La Grange.

UPSON COUNTY.

Mica-bearing pegmatite occurs from 1 mile to 3 miles south and 

southeast of Thomaston and 3 miles west of Kenzie near the E. E. 

Thompson house, in the northern part of Upson County. On the 

Thompson property weathered sheets of mica 4 to 10 inches across 

are found loose in the surface soils. This mica is clear and of good 

quality except for surface weathering.

IDAHO.

LATAH COUNTY. 

MICA DEPOSITS.

Deposits of mica have been found in several counties of Idaho, but 

only those of Latah County have been developed extensively. These
IDAHO. 87

were examined in 1910, and the conditions of the workings are described below as they were at that time. More recently the Producers 

Mica Co., of Chicago, has worked some of the properties, especially 

the Muscovite mine, on a large scale. Heavy shipments of mica have 

been made to the company's plant in Chicago where the mineral has 

been prepared for the market.

The deposits examined lie in a belt about 2 miles wide that extends 

north and south for several miles in T. 41 N., R, 2 W., from 3 to 6 

miles north of Avon. They lie at elevations of 3,400 to 4,700 feet 

above sea level, along the top and to the west of a high mountain 

ridge extending south from the Thatuna Hills. The principal properties are the Muscovite claim, about 5 miles north of Avon, in sec. 22; 

the Levi Anderson mine, about 4 miles north of Avon, in sees. 22 

and 27; the Maybe mine, about 1 mile southwest of the Muscovite 

claim, in sec. 22; and the Luella mine of the Western Mica Co., about 

1$ miles southwest of the Muscovite, in sec. 21. Other claims are 

owned by Alexander Munro and David Peterson, in sec. 15. In 

order from south to north along the ridge the mines are the Levi 

Anderson claim, the Muscovite, Atlas, Violet, and Morning Star 

claims, and the Sunshine claim of David Peterson. The Maybe and 

Luella mines are in the valley to the west of this ridge. The location 

of the different deposits is shown in figure 16. At the time of the 

writer's visit the Muscovite was the only mine in operation; it had 

been idle a few years and was being cleaned out preparatory to mining. The elevations given were determined by barometric measurement.

The mica deposits occur in an area of highly schistose metamorphic 

rocks of pre-Cambrian age. Muscovite and biotite schists and gneiss, 

in which quartz is generally a prominent constituent, are the principal types of rock in the region. Bands of the gneiss at some 

places contain crystals of black tourmaline, especially in places near 

large bodies of pegmatite. The schistosity of the gneiss and schist 

of this region strides roughly north and south and dips from 50° W. 

to vertical. Masses of pegmatite cut the gneiss and schist and are at 

many places entirely conformable with the schistosity and at others 

only in part or not at all. Some of the bodies of pegmatite crop out 

continuously for several hundred yards with few variations in thickness or direction. Others have smaller outcrops. At some places 

the bodies of pegmatite bulge or swell into chimney-like deposits, 

and contain rich deposits of mica. The gneiss and schist apparently 

contain more pegmatite in the valley west of the high mountain, 

ridge than in the ridge itself. The miners say that the deposits along 

the top of the mountain are on the same ledge of pegmatite, but this 

has not been proved. There may be separate sheets of pegmatite that
MICA DEPOSITS OF THE UNITED STATES.

do not connect, though they may be nearly in line with one another 

or may overlap. Even if a single body of pegmatite should prove 

so persistent as to extend over several claims, its content of mica is 

variable and at some places it contains none.

f-EVI ANDERSON 

PROPERTY

FIGURE 16. Sketch map showing position of mica deposits in Latah County, Idaho.

The beds have been folded, but in the small area under consideration the larger folds can; not easily be distinguished. Small folds 

whose dimensions can be measured in feet and whose schistosity is 

turned across the bedding were observed at a few p^ces. In general
IDAHO. .. . 89

the strike and dip are rather regular for a region of tilted metamorphic rocks.

LEVI ANDERSON MINE.

The Levi Anderson mine is in a low, rounded knob on the ridge, at 

ai^ elevation of nearly 4,100 feet. The main opening is on the east 

side near the top, and a second opening has been made about 200 

yards to the north at a lower level. The main working consists of 

an open cut about 20 feet wide, 30 feet long, and 15 feet deep, with 

short tunnels to the north and to the south and an incline from the 

bottom. The workings have fallen in badly. As exposed in the 

open cut the pegmatite is about 20 feet wide and approximately 

conformable with the inclosing rock. The country rock is mica schist 

and gneiss, the schistosity of which strikes N. 10° W. and dips 60° W. 

The pegmatite contains much quartz and some black tourmaline 

and beryl. Only small crystals and sheets of mica Avere seen around 

the mine, but mica in rather'large sheets was seen in the possession of 

Mr. Anderson, at Spokane. At the other working a shaft was sunk 

on a ledge 'of pegmatite. Only small blocks of mica were left around 

this opening also. Part of the muscovite was associated and intergrown with biotite.

A prospect was opened for mica on the roadside on the spur of 

the mountain ridge about half a mile south of the Levi Anderson 

claim, about 3,800 feet above sea'level. Little could be seen of the 

formation encountered or the mica found.

MUSCOVITE MINE,

The Muscovite mine was first worked in 1888 by Woody & Lamb. 

After that it was operated intermittently, and the last work was done 

by the Muscovite Mica Co., of Spokane. The mine then passed into 

the hands of Alexander Munro, of Moscow, Idaho, and later into 

those of the Producers' Mica Co., of Chicago. The "vein" in the 

Muscovite mine cuts through the apex, of a sharp knob whose elevation is 4,450 feet. The position of the different workings is shown 

in figure 17. An open cut with a shaft has been made on the outcrop at the apex and other open cuts with drifts and a 60-footi shaft 

to the south on the hillside. The principal work was done from two 

crosscut tunnels with drifts and stopes at the ends. One of these 

tunnels was 150 feet lower than the apex and on the east side of the 

hill; the other was on the southwest side of the knob and 200 feet 

lower than the apex, and in June, 1910, this was the only part of 

the mine open for examination. Another crosscut tunnel was started 

still farther down, about 325 feet below the apex;- this has been 

driven about half of the 600 feet necessary to reach the " vein." 

Other test pits have been made nearly a quarter of a mile south of
90 MICA DEPOSITS OF THE UNITED STATES.

the apex, on an outcrop of pegmatite, which may or may not be the 

same "vein." The tunnel open for examination had been driven

PEN CUT WITti TUNNEL

FIGUKB 17. Sketch map showing position of workings on Muscovite mica claim, Latah

County, Idaho.

some 200 feet to the " vein." More than 300 feet of drifts, in which 

much stoping was done, were then carried to the north. At the
IDAHO. 91

junction of the tunnel and the drift at this level a room for a turntable had been made during earlier operations. The timbers of the 

roof over this turntable and of the stopes in places farther along 

had given way, so that in order to reach the better part of the mine 

it was necessary to drive a new tunnel alongside of the main original 

drift. The 60-foot shaft formerly connected with the drift at the 

?nd of the crosscut tunnel. A short crosscut tunnel to the west of 

the new drift cut a pegmatite " vein," from 12 to 18 inches thick, in 

which small blocks of good mica and some beryl crystals were found.

The main pegmatite " vein " ranges in thickness from 4 to .6 feet 

in the main original drift and the stopes above and widens out to 

12 feet thick at the end of the drift, where the vein includes a horse 

of gneiss several feet across. There was a large showing of mica 

" books," some of good size, in the end of the tunnel and at two places 

in the stopes above. It is said that the best mica in sight had been removed when mining was stopped, though even then the " vein " contained sufficient mica to be termed rich. In the open cut at the 

apex the pegmatite mass encountered appears to be nearly 40 feet 

thick. The pegmatite at this point and to the side of the open cut 

carries considerable quartz. A portion that had hot been mined still 

contains numerous blocks of fair-sized mica on the outcrop.

The country rock is strongly foliated muscovite-biotite gneiss. It 

strikes N. 10° W. to N. 10° E. and dips about 70° W. The pegmatite is conformable, or nearly so, with the gneiss. The course of 

the pegmatite is fairly regular, but a few minor deformations were 

encountered in the workings. Evidently the outcrop at the apex 

represents a large bulge or swelling of the pegmatite. The increasing thickness of the pegmatite in the end of the drift 200 feet lower 

than the apex indicates a continued thickness with depth. This drift 

probably does not lack more than 60 or 70 feet of being under the 

apex. This chimney or shoot of pegmatite outcropping at the apex 

is considered to be the richest part of the " vein." In the tunnel on 

the east, 150 feet lower than the apex, a large vein very rich in mica 

is reported to have been encountered. A peculiar feature of the 

" vein " is the small amount of quartz and feldspar it contains at a 

distance from the apex chimney. In the chimney the quartz and 

feldspar are plentiful and the pegmatite is more nearly normal in 

composition.

No records of the production of mica from this mine have been 

kept, but Mr. Munro estimates that during two periods of operation 

at least $40,000 worth of mica was taken out each time. The quality 

of the sheet mica from the Muscovite mine is very good, the color 

being light rum and sheets clear. The proportion of good sheet 

mica obtained from an average lot of " books " would probably not 

equal that obtained from some of the better mines in other parts of
92 MICA DEPOSITS OF THE UNITED STATES.

the country, though perhaps only a few mines yield so abundantly 

from an equal amount.of vein matter.

MORNING STAR CLAIM.

The two claims taken up by Alexander Munro, prior to 1910, 

extending to the north from the Muscovite, are intended to cover the 

outcrop, if any exists, of the pegmatite between the Muscovite and 

the Morning Star. The pegmatite in the Morning Star claim outcrops strongly for some distance along the east side of the ridge. 

The hill slope below is steep, at some places almost cliff-like. The 

pegmatite is about 20 feet thick and incloses a horse of gneiss, or 

there are two ledges of pegmatite separated by a sheet of gneiss. 

The ledge is conformable with the mica schist country rock and 

strikes north by east with a dip of about 60° W. Both the schist 

and the pegmatite contain black tourmaline. Only a little mica is 

exposed in the outcrop of this ledge. About 450 feet lower a crosscut tunnel was started on the east side of the ridge and driven 660 

feet under the outcrop. The dip of the pegmatite carries it .still 

farther west, and the tunnel will probably have to be carried about 

90 feet farther. The rocks through which the tunnel cuts are 

muscovite and biotite schist and gneiss, which in places show a 

slight banding across the foliation. The schistosity strikes east of 

north and dips 50°-70° W.

SUNSHINE CLAIM.

The Sunshine claim adjoins the Morning Star on the north. The 

ledge of pegmatite crops out strongly on the hillside and is probably 

the same ledge as that opened on the Morning Star. An open cut 

20 feet long and 10 feet deep has been made in the hillside on a body 

of pegmatite striking north by east and dipping 50° W. It is conformable with the schistosity of the inclosing gneiss. Very little 

mica was found in this cut. The pegmatite carries tourmaline and 

some garnets larger than walnuts. It is said that a better showing 

for mica was found in a prospect opened about 200 yards to the 

north, over the hill.

MAYBE MINE AND ADJACENT PROSPECTS.

The Maybe mine, sometimes called the Silver White mine, is in a 

steep hillside.in the bend of a stream. Several tunnels have been 

run into the hill and a few pits and other openings have been made, 

but these have caved in so badly that little could be seen. Either 

there are two or more ledges of pegmatite, or a single ledge is folded 

and lies somewhat like a blanket on the hillside. In one of the 

openings the schistosity of the mica schist country rock has a strike
IDAHO. 93

of N. 55° W., about parallel with the contour of the hill at that point. 

The pegmatite carries considerable tourmaline and some garnets, 

the largest as big as walnuts. The mica is clear and of a very light 

color, inclining to rum. The waste mica left around the mine shows 

that the sheets are of good quality and split well.

On the hillside across the small stream east of the Maybe mine 

several prospects for 'mica were worked long ago. The indications 

for mica here are good. A few hundred yards southwest of the 

Maybe mine, near the corner of the claim, another body of pegmatite was prospected for mica, A very good deposit of mica was 

found in the open cut, but a tunnel started 15 feet lower down very 

quickly lost the main "vein" and followed a stringer for nearly 

300 feet.

LTJELLA MINE.

The Luella mine was opened by a crosscut tunnel, run southwest, 

and an open cut on the outcrop above it. Evidently a large deposit 

of pegmatite was found and much of it was stoped out. Only small 

blocks of mica, though of good quality, were left around the mine. 

The blocks of pegmatite on the dump contain black tourmaline and 

pink garnets, some of which are embedded in crystals of mica. The 

country rocks are muscovite and biotite schist and gneiss. Blocks of 

fine-banded tourmaline-quartz rock, associated with the schists, were 

left on the dump.

CONDITIONS AFFECTING DEVELOPMENT.

The operation of mines in this region is facilitated by an abundant 

supply of good timber. Part of this timber is included in the claims 

and part is either on State land or in the Coeur d'Alene National 

Forest. On the mountains the more abundant trees are tamarack or 

larch and red fir; in the valleys there are good stands of white pine, 

red ?pine, tamarack, red fir, and cedar. The rocks are not hard to 

drill, and Mr. Munro states that in some of the mines tunnels can be 

driven at the rate of 3 feet a day without power drills. The shipping 

point for the mines is Avon, on the Washington. Idaho & Montana 

Railway.

WASHINGTON COUNTY.

Specimens of mica were received by the United States Geological 

Survey in January, 1916, from Fred Mullin, of Council, Idaho. 

They were found by Gilman Rinehart about 12 miles southeast of 

Council, near Middle Fork of Weiser River. The specimens consisted both of clear mica with smooth, flat cleavage and of A mica. 

The clear mica would trim into sheets of 2 by 2 and 1$ by 3 inches. 

It has a dark-green color in thick sheets, splitting down to material 

suitable for glazing.
94 MICA DEPOSITS OF THE UNITED STATES.

MAINE. 

GENERAL FEATURES.

. Mica mining has never been a large industry in Maine, but some 

deposits have from time to time made a small output. About 2,000 

pounds of sheet mica, valued at $2,000, was produced in Maine in 

1880, according to the Tenth Census. 42 In the reports on the Mineral Kesources of the United States for 1882, 1883, and 1884, published by the United States Geological Survey, mention is made of 

mica mining in progress during those years. Mica was sold from the 

Mount Mica tourmaline mine, and unsuccessful attempts were made 

to work deposits in Gilead and Albany. The deposits are in Oxford, 

Androscoggin, and Sagadahoc counties, in the southwestern part of 

the State. Many of them have been described by E. S. Bastin,43 

whose descriptions are given below and supplemented by brief notes 

made by the writer during a visit to some of the gem-bearing pegmatites in 1913.

Most of the mica produced in Maine is obtained as a by-product in 

mining feldspar and gems. A small part of it is suitable for use as 

sheet mica, but most of it can be used only for grinding because of 

its segregation into compact masses in such a way that individual 

crystals have interfered with one another's growth and the presence 

of A, wedge, and fishbone structures. A figure given by Bastin to show 

the wedge and fishbone structures found in mica from Topsham is 

reproduced in Plate V.

ANDROSCOGGIN COUNTY.

Several quarries have been operated by the Maine Feldspar Co. 

on Mount Apatite. 3^ miles west of Auburn. Orthoclase and microcline with minute intergrowths of perthitic albite are quarried from 

a large bed or ledge of pegmatite that covers much of the summit of 

the hill. Variable quantities of muscovite mica are found, as well as 

other minerals, such as biotite, black tourmaline, occasional colored 

and gem tourmaline, lepidolite, garnet, and beryl.. Mica is fairly 

plentiful, but none of it is suitable for making sheets, for the A and 

wedge structures are strongly developed in it. Some bladelike crystals of mica are a foot long. Similar mica is found in the Wade and 

Pulsifer quarries, on the northwest side of Mount Apatite. It would 

probably pay to save the mica at the different quarries to sell as scrap 

for grinding, but much of it is thrown away.

42 Mining industries: Tenth Census, vol. 15, p. 850, 1886.

<3 Geology of the pegmatites and associated rocks of Maine, including feldspar, quartz, 

mica, and gem deposits : U. S. Geol. Survey Bull. 445, 1911.
MAINE. 95

OXFORD COUNTY. 

BENNETT PROSPECT.

A small mass of pegmatite on the farm of F. H. Bennett, in the 

western part of Albany, about 5 miles west of Hunt Corners, has 

been prospected for mica by W. S. Robinson. The pegmatite is 

exposed to a thickness of 10 feet and is intrusive in granite gneiss 

like that farther west. The pegmatite is a coarse association of 

quartz, muscovite, orthoclase, and black tourmaline. The muscovite 

occurs in graphic intergrowth with quartz and also in "books," the 

largest 6 inches across, though most of them measure less than 3 

inches. Nearly all of it is wedge mica and shows twinning. The 

feldspar here is too intimately mixed with black tourmaline to be of 

any value. Neither the quantity nor the quality of the materials 

here seem to warrant further development.

PINGREE PROSPECT.

Another mass of pegmatite, on the farm of C. P. Pingree, in the 

extreme western part of the town of Albany, was worked for mica 

in 1878-79 and was opened again in 1900 by W. S. Robinson, but no 

shipments were made except of samples. The ledge has yielded some 

gem beryl. In the absence of the owner of this property the writer 

was unable to visit it. Bethel, the nearest station, is about 8 miles 

distant on the Grand Trunk Railway.

HICKS POND PROSPECT.

A mica prospect was opened in pegmatite in the southern part of 

the town of Greenwood, about three-quarters of a mile east of Hicks 

Pond. The pegmatite is composed largely of quartz, muscovite 

mica, albitfe of the clevelandite variety, and some potash feldspar. 

Some of the mica crystals are 14 inches across and a foot thick, but 

twinning and wedge structure have made most of them useless for 

sheets. At some places about half the rock is composed oi mica. 

Gem tourmaline has been taken from pockets or cavities in the 

pegmatite.

HIBBS FELDSPAR AND MICA MINE.

A small feldspar and mica mine was opened in 1906 on the farm 

of Alton Hibbs, about 1| miles north of Hebron village, near the 

Buckfield road. The operators were J. A. Gerry, of Mechanic Falls, 

and W. Scott Robinson, who abandoned it in 1907. The property 

was visited by the writer in August, 1906, after considerable stripping and prospecting had been done. The ledge was exposed for 

300 to 350 feet along the southwest side of the valley of a small creelc
96 MICA DEPOSITS OF THE UNITED STATES.

N E.

^Micaceous band

GreetFIGURE 18. Relations of pegmatite and wall rock at Hibbs 

feldspar and mica mine, Hebron,. Maine.

The width of the outcrop averaged about 30 feet, but increased 

at one point to at least 50 feet. Only shallow excavations had been 

made, exposing numerous masses of pure orthoclase-microcline feldspar 2 to 3 feet across, associated with much graphic granite. The 

spar is mottled buff to blue-gray. Small quantities of albite are 

found. The principal iron-bearing impurity is black tourmaline, 

so aggregated that it can be readily separated in the mining. Feldspar of grade suitable for making pottery formed about 60 per 

cent of the rock mined. Small quantities of biotite in the usual lathshaped crystals, some as large as 1 foot by 3 feet, were also seen. 

Muscovite is found in most parts of the pegmatite mass in " books " 

2 to 3 inches across, but it occurs in abundance and in larger plates 

only at its southwestern border, where, in a zone averaging 3 to 4

feet in width, the 

mica books average 

5 inches across and 

one imperfect book 

reaches a diameter 

of 30 inches.

The muscovite 

forms on the average at least 10 per 

cent and in some places 20 per cent of the rock, and fully 60 per cent 

of it could be trimmed into plates, the remainder being usable only as 

scrap mica. Wedge structure and ruling are the common defects. 

Plates as large as 5 by 6 inches could be trimmed from a few of the 

mica " books."

The exposures are not numerous enough to reveal the full form or 

extent of the pegmatite mass. On its southwest side it is bounded 

by quartz-mica schists, which trend from; N. 30° W. to N. 50° W.. 

averaging about N. 45° W., and apparently dip about 45° NE. The 

northeast border of the deposit is wholly obscured by drift. The 

mica-rich band that follows the southwest margin of the pegmatite 

mass can be traced for 300 to 350 feet nearly the whole distance 

through which the pegmatite mass itself is exposed. The apparent 

 relations of the pegmatite and schist are shown in figure 18.

The exposures seen by the writer indicate that this property is a 

promising one for both feldspar and mica mining. Further stripping will probably show that the deposit extends northwest and 

southeast of the present exposures, and as it seems to be steeply 

inclined there is no reason why it should not persist in good quality 

to considerable depth. The development work was suspended for 

reasons wholly aside from the quality of the deposit. The output 

must be hauled by teams 3 miles to Hebron station, on the Kangeley 

division of the Maine Central Railroad.
MAINE.

MILLS QUARRY.

The Mills feldspar quarries consist of two pits about a quarter of 

a mile apart on Hill No. 4, near the line between the towns of Hebron 

and Paris. The feldspar quarried consisted chiefly of the potash 

varieties but included some of the soda variety, albite. Small segregations of quartz, are scattered through the pegmatite. Bunches of 

wedge-shaped and A mica crystals occur in parts of the pegmatite. 

Mica was saved during mining, but practically the whole output was 

suitable only for grinding.

MOUNT MICA.

Mount Mica is about 1£ miles east of the village of Paris. It has 

been famous for the gem tourmaline and the specimen minerals it 

has yielded since it was discovered in 1820, but it has produced also 

some mica and 

feldspar. The 

AV o r k started 

with shallow 

pits along the 

outcrop and 

has been carPortions excavated

prior to 1908 S E.

r i e d progressively deeper 

the

Schist and gneiss 

Pocket-bearing zone

Normal unproductive 

pegmatite

FIGURE 19. Diagram showing geologic structure at Mount Mica 

tourmaline mine, Paris, Maine. (After Bastin.)

toward

southeast. The present depth is from 20 to 30 feet along the southeast face of the quarry.

The country rock is schist, which contains quartz, muscovite, 

biotite, feldspar, garnet, and probably fibrolite. Strikes measured 

on the schist ranged from east and west to north by west and dips 

from 10° to 25° south and east. The pegmatite dips 20°- 30° SE., 

as shown in figure 19, taken from Bastin's report. The mass of 

pegmatite is large, but its full thickness is not exposed. About 7 

feet of the upper part is worked for gem minerals, and from this 

layer the mica and feMspar were also obtained. The best gem and 

specimen minerals were obtained from pockets; the other minerals 

from the solid pegmatite in which .the pockets occur.

The principal constituent minerals of the pegmatite are quartz, 

orthoclase, microcline, muscovite, biotite, and black tourmaline, with 

the clevelandite variety of albite, lepidolite, and colored tourmalines 

in the gem-bearing zone. Graphic intergrowths of feldspar and 

quartz, which are common in many of the other tourmaline-bearing 

pegmatites of New England, are comparatively rare at the Mount 

Mica mine. Quartz occurs through the pegmatite in small irregular 

masses of a white to slightly smoky color and in groups of color-
98 MICA DEPOSITS OF THE UNITED STATES.

less crystals in the pockets. Orthoclase and microcline are .the principal feldspars of the pegmatite and have been gathered from the 

dumps for use in pottery. Muscovite occurs in graphic intergrowths 

with quartz in bunches of wedge and A-shaped crystals and in flat 

crystals, a few of which measure more than a foot in diameter. 

Some of the mica has a clear light rum color and good cleavage and 

is purchased by mica-manufacturing companies. Much of it has 

been sold as it came from the mine for about $25 a ton.

YORK PROSPECT.

A prospect was opened on the farm of J. P. York, near the central 

part of the town of Peru. The principal minerals of the pegmatite 

are potash feldspar, quartz, muscovite, and biotite. The feldspar 

crystals are so intermixed with biotite that it would not pay to 

separate them for use in making pottery. Most of the muscovite 

crystals are less than 4 inches in diameter, and the best specimens 

preserved in a neighboring house would not have yielded sheets 

larger than 2 by 3 inches.

BLACK MOUNTAIN MICA MINE.

A deposit of pegmatite on Black Mountain, in the northern part of 

the town of Rumford, has been mined for scrap mica by Oliver 

Gildersleeve, of Gildersleeve, Conn., who has dug two pits about 

two-thirds of the way up the western slope of the mountain, about 

three-quarters of a mile from the road between North Rumford and 

Roxbury Notch. The upper pit is about 200 feet long, 50 feet wide, 

and 25 feet in greatest depth. The lower pit is about 100 feet wide, 

100 feet long, and 35 feet in maximum depth.

The rock at these pits is an exceedingly coarse pegmatite, which 

has been intruded irregularly into metamorphosed sedimentary beds 

that trend N. 30°-40° W. and dip T0°-80° NE. These beds are 

slightly contorted but reveal their sedimentary origin through an 

alternation of quartzitic and more shaly beds.

The pegmatite here is different in some respects from that at the 

other deposits in Maine, though in general it approaches the pegmatite of the gem-tourmaline localities. It contains little or no potash 

feldspar, the dominant feldspar being albite of the bladed variety of 

clevelandite. Muscovite is the mineral next in abundance, constituting generally 30 to 40 per cent of the whole deposit, though it locally 

forms three-quarters of the mass of pegmatite. The largest crystal 

of mica seen by the writer was 1£ feet wide and 3 feet long, but bladeshaped or spearhead-shaped crystals 1 to 2 feet long are very common. 

Some masses of almost pure mica weigh half a ton. All the mica 

shows one or more of the defects known as twinning, wedge structure,
MAINE. 99

and ruling. None of it will yield any plate mica. Several of the 

mica books observed were 1 foot thick at right angles to the cleavage. 

Near the walls of the pegmatite mass the mica books tend to orient 

themselves with their long axes perpendicular to the contact, though 

only within 6 inches or so of the wall is there any noticeable decrease 

in the coarseness of the pegmatite. Most of the quartz of this pegmatite is opaque but is pure white. Spodumene is unusually abundant and occurs in long, flat light-gray to white crystals, some of them 

2| feet long and 3 to 4 inches thick. Some of the spodumene is intimately intergrown with quartz.

A remarkable feature of this deposit is the presence in the pegmatite of irregular masses of medium-grained granite, which in some 

places consists of muscovite, quartz, and plagioclase, and along certain bands or irregular bunches one-third to one-half the rock consists of bright-pink tourmaline, producing a stone of considerable 

beauty.

The quarry was opened about 1901 by Oliver Gildersleeve and 

was worked for four seasons. About 250 tons of mica is reported to 

have been min$d in 1905. The quarry was idle throughout 1906, in 

which year the writer visited it, and so far as is known has not reopened since. Steam drills were employed and sheds built for hand 

picking the mica, which was packed in 100-pound bags and hauled 

by team 7 miles to Frye, on the Eangeley division of the Maine 

Central Eailroad. From Frye it was shipped to a grinding mill at 

Gildersleeve, Conn. About 1,000 tons in all are reported to have 

been shipped. The quantity of scrap mica still available at this 

quarry is large, but there is no plate mica, nor is it probable that 

further excavation will disclose any.

BEECH HILL MICA MINE.

A deposit on Beech Hill, in the town of Waterford, on the farm 

of George L. Kimball, has been operated for mica on a larger scale 

probably than any other deposit in the State. The mica, is a constituent of a sill-like mass of coarse pegmatite, which dips about 30° 

E. and which is at least 12 feet thick, though its base is not exposed. 

The commercial mica is confined to a zone about 5 feet thick in the 

lowest part of the pegmatite layer now exposed. The muscovite 

within this 5-foot zone forms 10 to 20 per cent of the pegmatite.

Some of the masses of pure orthoclase feldspar associated with the 

mica are 5 feet across, but the total quantity present is not sufficient 

to make it commercially valuable. Intergrowths of quartz and 

muscovite are common.

The pegmatite contains no biotite and no black tourmaline. The 

associated rock is a granite gneiss, and both gneiss and pegmatite 

are intruded by a dike of diabase.
100 MICA DEPOSITS OF THE UNITED STATES.

Some of the muscovite books are a foot across, but most of them 

are less than 5 inches. The larger plates are invariably cut by ruling 

planes into a number of smaller pieces. Much of the mica is worthless for anything but scrap because of ruling, wedge structure, and 

twinning. Most of the thumb-trimmed material seen by Bastin was 

in pijeces 2 or 3 by 3 inches across. The mine was not being worked 

at the time of the writer's visit in September, 1906. Although several 

tons of mica lay in the trimming sheds the best of the output was 

reported to have been sold, so that it was impossible to make a fair 

estimate of the average value of the mica mined, but the material 

is superior to that from any other mine in Maine.

The property was opened in 1900 and was worked also in 1902 by 

the Beech Hill Mining Co., which subsequently sold it to New York 

investors. About a ton of thumb-trimmed mica was marketed at 

prices ranging from 8 cents to $1 a pound, and about 10 tons of scrap 

mica was sold. The remainder of the material quarried was still in 

the mine buildings.

SAGADAHOC COUNTY.

G 

MOUNT ARARAT FELDSPAR QUARRIES.

Two quarries have been opened on Mount Ararat, about a mile 

north of Topsham village, one on the east slope and the other on the 

north slope of the hill. There are two pits at the eastern quarry and 

one at the northern. In the eastern quarry large and small masses of 

cream-colored to white potash feldspar, gray to smoky quartz, and 

graphic granite were encountered. Mica is an abundant constituent of the pegmatite exposed in the upper pit. It is pale green to 

nearly colorless and some of the crystals are as much as 10 inches in 

diameter. Most of the mica is of the wedge variety and shows twinning and is therefore suitable only for grinding. A small quantity 

of sheet mica is obtained, some of which would trim into sheets 4 

by 5 inches. Most of the sheet mica is specked with thin films of 

magnetite. A few imperfect crystals of columbite occur in the 

quartz-feldspar masses.

In the northern quarry there is a very irregular association of 

quartz, feldspar, muscovite, biptite, garnet, and rarer minerals. 

Muscovite is not plentiful and none of it is suitable for making 

sheets.

FISHER'S FELDSPAR QUARRY.

A quarry was operated for feldspar by J. A. Fisher 1£ miles 

west-northwest of Cathance station, on the northern valley slope of 

Cathance River. None of the minerals show a regular arrangement in the pegmatite except the mica, which occurs principally 

along certain zones, but these zones have no definite trend with
MARYLAND. 101

respect to the general outlines of the deposit. Apparently all the 

mica is of the wedge and A varieties. In places the pegmatite contains more biotite than muscovite mica, especially in the finergrained parts.

G. D. WILLES'S FELDSPAR QUARRY.

A quarry was operated by G. D. Willes, of Brunswick, for the 

Trenton Flint & Spar Co., about 2 miles northwest of Cathance 

station. The pegmatite contains very large masses of pure feldspar, 

quartz, and graphic granite. A mass of pure white quartz was 

exposed through a distance of 50 feet and a height of 10 feet at the 

north end of the quarry. The feldspar is chiefly of the potash 

variety, and some of the crystals measure 15 feet across. The mica 

is concentrated along certain belts that traverse the pegmatite in 

several directions. These belts consist of heterogeneous aggregates 

of small crystals (solid mica) that grade into similar aggregates of 

spearhead-shaped crystals, some of which stand nearly perpendicular 

to the general plane of the mica belt. The largest of these spearhead-shaped crystals are a foot long. In the southern part of the 

quarry the mica occurs in nearly equidimensional masses, some as 

much as 5 feet across, composed of the same heterogenous aggregates of small crystals, which also grade into larger aggregates of 

spearhead-shaped crystals that branch out into the surrounding 

quartz, feldspar, and graphic granite. Bastin saw no sheet mica.

MARYLAND. 

GENERAL FEATURES.

Mica has been prospected or mined at several places between 

Washington, D. C., and Ellicott City, Md., in Howard and Montgomery counties. Several prospects were examined in 1910 and in 

1914. The deposits lie in three groups, one about 6 miles northwest 

of Laurel, in Howard County; another 4 or 5 miles N. 65°-75° E. of 

Laurel, in both Howard and Montgomery counties; and the third 

about 4 miles northeast of Kensington, in Montgomery County. 

These deposits lie in typical rolling Piedmont country at a distance 

from the streams and from the steeper valleys in areas along the 

larger streams where the relief is 50 to 200 feet.

The deposits are associated with highly metamorphosed schists 

and gneisses, which contain an abundance of mica and in some places 

considerable garnet. These rocks are strongly folded and crumpled 

and in places contain bodies of pegmatite, a few of which carry mica 

worth prospecting for. The schist arid gneisses appear to be 

identical with the rocks of the Carolina gneiss as mapped by A. 

111375 23 8
102 MICA DEPOSITS OF THE UNITED STATES.

Keith *4 and weather down to a highly micaceous soil. These rocks 

are mapped as Baltimore gneiss by the Maryland Geological Survey.45

BALTIMORE COUNTY.

Deposits of pegmatite occur in Baltimore County and have been 

prospected for mica in a few places. In 1915 specimens of surfaceweathered sheet mica were received at the United States Geological 

Survey from George E. Swem, of Cockeysville. The sheets measured 

24 by 3£ inches but were so badly cracked around the borders that 

they were unfit for use. The mica was clear and colorless in thin 

sheets, and if the deposit is mined below the limit of surface weathering it may yield sheets large enough for use in glazing.

Deposits have also been reported by C. Lyon Rogers, jr., near McDonogh; by August H. Mattheiz, of Baltimore, near Hollofield 

station on the Baltimore & Ohio Railroad; and by other parties near 

Woodstock.

HOWARD COUNTY. 

MARYLAND MICA CO.

Three deposits have been worked on the land of Charles Myer, If 

miles N. 5° W. of Scaggsville, or about 6 miles northwest of Laurel. 

Two of these were opened by old workings and the third was opened 

by the late William Theis, of Ellicott City, Md., in 1909. Work was 

done in 1914 by the Maryland Mica Co., the present owners, under 

the management of J. O. Arrington, of Overlea, Md. One of the 

prospects is in a steep knoll about 150 yards southeast of the house. 

It is said that this prospect was opened about 1885 by a shaft 45 

feet deep. No work has been done recently and there is now on the 

summit of the knoll a shallow pit or sink 20 feet across and 3 feet 

deep. The ground in and around this sink is covered with scrap 

mica and earth to a depth of a few feet. Some of the mica plates are 

as much as 6 inches across, and a few are firm and clear enough for 

punching. The pegmatite may occur in a short, thick body or chimney that crops out at the summit of the knoll, though there are indications that it has an easterly extension down the hill. The mica 

has a light, clear apple-green color and it splits to the best quality 

of "white" mica for stove use. The waste and scrap around the 

prospect could be screened out for grinding.

A little mica has been plowed and dug out of the surface soil about 

50 yards northeast of the prospect in the knoll, but no regular work 

has been done.

" U. S. Geol. Survey Geol. Atlas, Washington folio (No. 70), 1901.

46 Clark, W. B., Geological map of Maryland, Maryland Geol. Survey, 1907.
MARYLAND. 103

The prospect opened by William Theis is about 150 yards east of 

Myer's house. The work consists of an open cut, 25 feet long and 2 

to 10 feet deep, run northward into a hillside along a pegmatite 

ledge, and a second cut started 50 feet to the south to crosscut the 

" vein." The pegmatite strikes about north and crops out 30 feet 

farther up the hill, above the open cut. The dip could not be measured. The country rock is mica gneiss in highly schistose layers. 

The pegmatite contains considerable quartz, part of which, though 

smoky, is nearly clear. The feldspar is the flesh-colored potash variety, 

partly decomposed. The mica occurs in pockets in this deposit, and 

all that was mined came from one pocket several feet long and about 

2 feet thick, which is apparently exhausted. The mica was found 

in blocks or crystals weighing from 1 to 50 pounds and measuring 

from an inch to a foot in diameter. This mica is brownish-green 

and much of it is specked. Most of the crystals have the A structure 

strongly developed, so that only small perfect sheets can be cut from 

large blocks. Wedge-shaped blocks of mica occur, especially where 

the smaller crystals are bunched with quartz. Some of the larger 

blocks of mica would cut sheets 4 by 6 inches, though there would 

be a large quantity of waste in trimming.

Work was done by the Maryland Mica Co. around an old shaft in 

a knoll about 50 yards east of the house. A few surface pits and a 

trench were made southwest of the shaft, but the main work consisted of a drainage cut 60 feet long, 7 feet wide, and 1 foot to 10 feet 

deep, run in from the hillside on the east, and a tunnel driven from 

the inner end of the cut to the old shaft. Here difficulties were encountered because of caving ground, and work was stopped until 

the old shaft was cleaned out. This shaft was several feet deeper 

than the tunnel, which was about 25 feet below the surface of the 

knoll. A few pockets of mica were found in the work in the main 

pegmatite deposit near the shaft and in a smaller " vein " cut in the 

tunnel southeast of the shaft. Most of the mica obtained is more or 

less clay stained and though it would yield a few small-sheet and punch 

sizes would chiefly be used as scrap. It is green, and most of it 

is clear, but part is a little specked.

PARLET PROSPECT.

A prospect was opened by a shaft sunk some years ago on the 

Parlet place, 1^ miles north of Scaggsville. In 1914 the shaft was 

filled to a level within 15 feet of the surface. This shaft exposed a 

body of pegmatite about 10 feet thick, which included horses of 

mica gneiss. The formations have an east and west strike and a 

high north dip. Both the gneiss and the feldspar of the pegmatite 

are badly decomposed. Quartz segregations more than a foot thick 

were exposed in the walls of the shaft. Only a few small clay-stained 

apple-green crystals were observed around the prospect.
104 MICA DEPOSITS OF THE UNITED STATES.

BEN MURPHY MINE.

The Ben Murphy mine is 1 mile S. 55° W. of Scaggsville, in a 

small ravine entering a branch from the west. It was opened by a 

cut 60 feet long in a S. 25° W. direction and a shaft in the southwest 

end of the cut. The cut is 12 feet deep, but the depth of the shaft was 

not learned. The country rock is strongly folded mica gneiss. The 

pegmatite is about 15 feet thick and incloses a large horse of mica 

gneiss. Clear apple-green mica crystals that show smooth flat cleavage were found. A few specimens of translucent to opaque yellowish-green beryl were found in the dump.

MONTGOMERY COUNTY. 

EARTH PRODUCTS CO.

The Earth Products Co.'s mines are 4 miles N. 70° W. of Laurel, 

or about 1£ miles northeast of Burtonsville, on the old Irvington 

farm. The mineral sought was feldspar, but several mica prospects on the property were tested. These prospects are about 150 

yards southwest of the old farmhouse, 100 yards east of the house, 

and 150 yards northeast of the house. The surface showings at 

these places were promising, but the results of the tests made were 

discouraging.

At the prospect 150 yards southwest of the house boulders of white 

quartz and pegmatite are scattered over a field, and rough plates of 

mica 2 to 6 inches across were plowed up around them. A belt of 

soil carrying mica crystals extends from the brow of the hill about 

75 yards southwest across the field. A prospect was opened near 

the brow of the hill, but the mica found was not as good as that 

plowed up in the field. Mica 2 to 6 inches wide was also found in 

shallow pits at the other prospects, but deeper shafts failed to find 

better material. In the prospect about 100 yards northeast of the 

house a number of opaque greenish beryl crystals were found. Another outcrop of pegmatite about one-third of a mile north of the 

house, near Patuxent Elver, contained mica crystals from 3 to 4 

inches'across. This prospect was mined for feldspar by the Earth 

Products Co. but failed to yield much mica.

The mica from the various prospects is light, clear apple-green, 

and where free of A lines splits into smooth flat sheets.

GILMORE OR B. H. WARNER MINE.

A mine was worked from 1882 to 1884 on the soutlnvest side of 

Northwest Branch, 4 miles N. 55° E. of Kensington. It was then 

known as the Gilmore mine but is now owned by B. H. Warner, jr., 

of Washington, D. C. The mine was worked by an open cut 60 feet
MASSACHUSETTS, MONTANA, NEVADA. 105

long, 15 to 25 feet wide, and 10 to 15 feet deep, driven S. 35° W. 

into a hillside, with a shaft and some underground work in the northeast end of the cut. The shaft has caved badly, so that the underground work could not be examined. It is reported that a crosscut 

tunnel was run to the west, turning southwest along a mica streak 

in the pegmatite.

The exposures are not good, but a study of those seen indicates 

that the pegmatite is from 10 to 15 feet thick and is inclosed conformably with the mica gneiss country rock. The gneiss strikes about 

1ST. 30° E. and dips northwestward. Little mica has been left on 

the dump, but several tons of badly weathered scrap mica is scattered around the site of the trimming house on a ridge about a. quarter of a mile northeast of the mine. Part of this scrap material is 

clear, light apple-green mica like that found near Scaggsville and 

Burlonsville and was probably brought to the trimming house from 

other mines, but the remainder, though nearly clear, is dusted 

through with fine microscopic specks of magnetite, like that found on 

the dump, and therefore came from this mine.

MASSACHUSETTS.

Massachusetts has been only a small contributor to the mica production of the United States, having been credited in 1880 46 with an 

output of 1,000 pounds, valued at $1,250. Twenty-five men are reported to have been engaged in the industry. B. K. Emerson 47 mentions the occurrence of pegmatite deposits (coarse granite) in the 

towns of Blandford and Chester, Hampden County, and near 

Knightsville, in the town of Huntington, Hampshire County. A few 

quarries have been opened for quartz and feldspar, and some of the 

deposits might yield good mica.

MONTANA.

Deposits of mica have been reported in Montana. One prospect,48 

8 miles southeast of Dillon, is said to have yielded plates 8£ by 18f 

inches. Another prospect was reported in the Benton Record,49 near 

Barker, in Cascade County. Mica of good quality is said to have been 

found in a " vein " 4 feet thick.

NEVADA.

Deposits of mica in Nevada are mentioned in the literature, but 

apparently the only attempt to \vork any of them was made by

40 Mining industries : Tenth Census, vol. 15, p. 850, 1886. 

47 U. S. Geol. Survey Geol. Atlas, Holyoke folio (No. 50), 1898. 

<8 Eng. and Min. Jour., vol. 47, p. 573, 1889; vol. 48, p. 2.30, 1889. 

*9 En£. and Min. Jour., vol. 32, p. 272. 1881.
106 MICA DEPOSITS OF THE UNITED STATES.

Daniel Bouelli, of Rioville, Nev., in 1893 and 1894. Mr. Bouelli 

furnished information 50 to the Geological Survey from which the 

following notes have been abstracted.' In 1893 and 1894, 500 pounds 

of sheet mica was shipped from Nevada to Hamburg, Germany, and 

1,300 pounds to Syracuse, N. Y. This mica had been trimmed of 

excess waste and was expected to yield sheets from 2 by 3 inches to 

8 by 10 inches, a good proportion of which were 3 by 5 inches. The 

deposits are in the Virgin Eange, Lincoln County, about 15 miles east 

by north of Eioville. Kioville is at the mouth of Virgin River, on 

Colorado River. One of the claims, the Pioneer, is about 5,000 feet 

above sea level, near springs, and is accessible to wagons. A belt of 

mica-bearing rocks crops out along the Virgin Range in a north by 

east direction, extending northward into Arizona.

A deposit of mica has been reported in the Ruby Mountain Range, 

of Elko County, where sheets ranging from 2 inches to 2 feet in diameter are said to have been found.

NEW HAMPSHIRE. 

GENERAL FEATURES.

Mica has been mined intermittently in New Hampshire since the 

early part of the nineteenth century, and for many years prior to 

1860 the mines of that State furnished practically all the mica used 

in the United States. Supplies were afterward obtained from mines 

in other States and from foreign countries, and the mines in New 

Hampshire were worked less regularly. The increased demand for 

mica has led to the opening of several new deposits and the reopening some old ones. Some of the old dumps have,been worked over 

for the smaller sizes of sheet mica and for scrap mica that had been 

thrown away.

Mica deposits have been mined in Grafton, Cheshire, Sullivan, Merrimack, Straffordj and Coos counties. The best deposits lie in a 

broken belt that extends from Keene through the middle of Cheshire 

County northward into Sullivan County and the northwestern pail 

of Merrimack County and north by east to about the center of Grafton County. The principal mining districts in this belt are in the 

towns of Rumney, Groton, Alexandria, Orange, and Grafton, in 

Grafton County; Danbury and Wilmot, in Merrimack County; 

Springfield and Acworth, in Sullivan County; and Alstead, Gilsum, 

and Sullivan, in Cheshire County. There are also a few mines in 

Wentworth, Dorchester, and Canaan, in Grafton County, and a 

mine has been worked on the town line between Newport and ClareK> Parker, E. W., Mica; U. S. Geol. Survey Mineral Resources, 1893, pp. 753-754, 1894.
NEW HAMPSHIRE. 107

mont, in Sullivan County. The shipping points have been E-umney, 

West Rumney (now Swainsboro railway station), Bristol, Canaan, 

Grafton Center (now Cardigan railway station), Grafton, Danbury. 

and Keene.

The mica deposits lie in broken mountain country at elevations 

ranging from lessjhan IjOQO _tqjnorei than 3,000 feet above sea level. 

Swampy areas, ponds, and lakes, such as are common in glaciated 

regions, occur in unexpected places among the hills; much of the 

country is thickly covered with second-growth timber and brush; 

and the roads away from the main line of travel are bad or indifferent, so that some of the mines are not easily accessible. Many of 

the farms in the mica region have been abandoned, and the roads 

have therefore been neglected and are bad, and a heavy growth of 

brush now mantles large areas. This desertion of the farms also 

makes it difficult for the miners to find boarding places or for the 

companies to purchase food and forage for the camps. The location 

of many of the mica mines and prospects in New Hampshire is 

shown on Plate XII.

The rocks of the mica region of New Hampshire are complex and 

consist of a series of metamorphio schists and gneisses with intruded 

granite and pegmatite. The mica deposits are not confined to rock 

of any one definite type. Hitchcock 51 states that most of the valuable deposits of mica are found in an area of fibrolite-mica schist, a 

subdivision of the " Montalban group " as mapped in his Geologic 

atlas of New Hampshire. Many of the largest mines are in areas 

of this rock, but some valuable mines are in areas of rock mapped 

under different names.

For practical purposes the rock with which the mica-bearing pegmatites are associated may be called mica gneiss. This rock, which 

is evidently of great age, includes highly metamorphosed schists and 

gneisses of various types, such as biotite and muscovite schist and 

gneiss containing layers rich in quartz or black tourmaline, garnet, 

etc. In places the gneiss is porphyritic.

CHESHIRE COUNTY. 

LAKIN PROSPECT.

A prospect for mica has been opened on the land of George A. 

Lakin, 1£ miles N. 25° E. of East Alstead, by E. Howard. When 

examined in October, 1914, the work consisted of an open cut, which 

was 5 feet deep on the lower side and 15 feet deep on the upper side. 

The country rock is granite, which is cut at different angles by streaks 

of pegmatite. The surface is covered with a sort of blanket deposit

51 Hitchcock, C. H., Geology of New Hampshire, vol. 3, pt. 5, pp. 89-91, 1878.
108 MICA DEPOSITS OF THE UNITED STATES.

of pegmatite. The pegmatite contains segregations of smoky-gray 

quartz and in places grades into the granite. Mica is rather plentiful, but a large proportion of it would be classed as scrap. Crystals 

of mica as much as 10 inches across have been found. The clear 

grades of mica have a light rum color. Common beryl crystals 1 

inch to 2£ inches in diameter and small crystals of opaque bluishgreen apatite are among the associated minerals.

PARSON KINK.

The Parson mine, worked by the Fitzgibbon Mica Co., is 1£ miles 

N. 5° E. of East Alstead, on the west side of the public road. The 

workings consist of several open cuts and pits within a distance of 

about 175 yards in a line extending N. 30° E. The largest of these 

pits is 50 feet wide and 200 feet long and from 10 to 40 feet deep. 

They were worked as open quarries, from which the waste and ore 

were removed. The last work, which was extensive, was done in 1906 or 

1907. The open cut at the northeast end of the workings, near the 

road, was cleaned out for examination in 1914. It is about 20 feet 

deep. The pegmatite exposed in this cut is more than 30 feet thick 

at the west end but pinches down at the east end near the surface. 

During 1915 it was operated by Leon Phillips for the American Mica 

Co., of Newton Lower Falls, Mass.

The country rock is mica gneiss containing layers of highly foliated 

muscovite-biotite schist. The pegmatite is probably at least 100 feet 

thick but incloses streaks of schist as well as large segregations or 

veins of quartz. The mica nearest the quartz is richest. One mass of 

quartz exposed in the northeast cut is more than 15 feet thick. Much 

black tourmaline, some in close association with the mica, was observed. The mica has a clear light rum color, and small pieces seen 

on the dumps possessed good cleavage. At the north end of the mine 

the pegmatite forks, part of it extending along the west side of the 

road and part pitching under the surface and evidently connecting 

underground with the vein of the Granite State Mica Co.'s mine.

GRANITE STATE MICA CO.'S MINE.

The mine of the Granite State Mica Co. has been in operation for 

several years. At the examination made in October, 1914, there 

was an open cut about 250 feet long extending northeastward. 

This cut ranges in depth from 15 to 90 feet, and is deepest in a 

stope near the southwest end. Near the middle it is about 60 feet 

deep. The deeper workings were filled with water at the time of 

examination, and mica was being mined chiefly at the northeast end of 

the cut. A derrick hoist and an incline track have both been used to 

hoist ore and waste from the workings, but most of the hoisting in
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XII

71"

MAP OF SOUTHERN NEW HAMPSHIRE SHOWING LOCATION OP MICA MINES AND PROSPECTS

Scale ioobooo 

to _ Q _ IQ__________20__________3O Miles

J^lometers
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XIII

A. VIEW NORTHEASTWARD ACROSS THE QUARRY OF THE FRANKLIN PLAYTER 

MICA-BERYL MINE, SULLIVAN COUNTY, N. H., SHOWING THE PINCHING OF 

PEGMATITE BETWEEN MICA GNEISS WALLS.

B. VIEW SOUTHWESTWARD OVER THE OPEN CUT OF THE GRANITE STATE MICA 

CO.'S MINE, CHESHIRE COUNTY, N. H.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XIV

A. VIEW N. 15° W. ACROSS THE MAIN OPEN Clj I OF THE I111UUA AUC.V 

CHESHIRE COUNTY, N. H.

B.'MICA CHYSTALS IN A FACE OF PEGMATITE IN THE DEEP STOPE 

UNDER OPEN CUT SHOWN IN A.
V. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XV

A. VIEW SOUTHWESTWARD ACROSS OPEN CUT OF THE FRENCH MICA MINE, 

CHESHIRE COUNTY, N. H.

B. VIEW NORTH OF EAST IN THE OPEN CUT OF THE KILTON MICA MINE, 

GRAFTON COUNTY, N. H.
U. S .GEOLOGICAL SURVEY BULLETIN 740 PLATE XVI

A. VIEW FROM MIDDLE OF NORTH SIDE OF OPEN CUT OF KEENE MICA 

PRODUCTS CO.'S MICA MINE, CHESHIRE COUNTY, N. H.

Horse of mica gneiss inclosed in pegmatite near center.

B. ENRICHMENT OF MICA IN PEGMATITE ALONG THE WEST SIDE OF THE 

HORSEJIOF MICA GNEISS SHOWN IN A.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XVII

A. FORK IN THE PEGMATITE AT GENERAL ELECTRIC CO.'S MICA MINE NEAR 

WEST RUMNEY, N. H.

B. VIEW NORTHEASTWARD DOWN INTO THE STOPES OF THE PALERMO MICA 

MINE, NEAR NORTH GHOTON, N. H.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XVIII

A. CONTACT BETWEEN PEGMATITE AND OVERLYING GNEISS AT SANBORN 

MICA MINE, GRAFTON COUNTY, N. H.

B. VIEW SOUTHWESTWARD ACROSS THE OPEN CUT OF THE BELDEN OR 

STANDARD MICA MINE, GRAFTON COUNTY, N. II.
NEW HAMPSHIRE. 109

recent years has been done with the derrick, the track having been 

abandoned. Conditions in the southwest half of the cut in June, 

1913, are shown in Plate XIII, B. The deepest part of the cut is below the place where the incline track has been removed. Because of 

the overhanging southeast wall it has been necessary to hoist a 

quantity of country rock from the workings.

The pegmatite cuts the >micji==gnj^s^c^un_t^ conformably with its average attitude that is, it trends northeast and has 

a high southeast dip. It is from 2 to 8 feet thick through much of 

the open cut and nearly 20 feet thick in the middle, though here it 

is thickest near the surface, pinching somewhat downward. The 

main pegmatite forks in places] offshoots branching to the northwest between the middle and southwest end and at the northeast end 

of the workings. Much of the pegmatite is medium to fine grained, 

but some has a coarse texture and contains large segregations of 

quartz. In most of the workings mica has been most plentiful near 

the hanging wall, but la small quantity is scattered through the 

pegmatite or occurs along the footwall. Crystals of mica more than 

2 feet across are reported. The muscovite has a clear light rum 

color and is of good quality. A little biotite is associated with it. 

Black tourmaline is plentiful in places. At the northeast end of the 

cut a 4-foot "vein" branching out from the main deposit carries 

much mica near the surface and little tourmaline, though the same 

vein several feet below carries much black tourmaline and little mica.

DAVIS MINE.

The Davis mine is 2£ miles N. 15° W. of Gilsum, on the southwest side of the road leading to East Alstead. This is one of the 

older mines of New Hampshire and, according to information furnished by Silvester Mitchell, of Gilsum, to James Davis, who last 

operated it, the mine was opened about 1810 by Simon Bowers. It 

was worked intermittently by three generations of the Bowers family 

and then by Silvester Mitchell. Prior to 1894, when Mr. Davis began operations, most of the mining consisted of open quarrying. 

The mine now belongs to the American Mica Co., of Newton Lower 

Falls, Mass. The Davis Mica Co. was well equipped with buildings, 

aerial tram, track, hoists, power drills, etc., and carried on extensive 

underground work. The workings are chiefly along the side of a 

low hill above swampy ground. From the shop an open cut extends 

southward about 100 yards and then northeastward about 100 yards 

to the road. (See fig. 20.) All the workings were filled with water 

to the level of the swampy ground west of the mine when the mine 

was examined in 1913 and 1914. The underground workings, as reported by Mr. Davis, consist of a shaft 93 feet deep and a drift 200
110 MICA DEPOSITS OF THE UNITED STATES.

feet long to the south opening into large stopes above. This drift 

and the stopes above lie east of the open cut.

The country rock is mica gneiss containing prominent layers of 

biotite schist carrying black tourmaline. The rocks have a variable 

north to northeast strike and a high east to southeast dip. The pegmatite is conformable with the inclosing gneiss through part of its 

course but bulges out in places, cutting across the schistosity of the 

gneiss. Horses of gneiss are inclosed in different parts of the pegmatite, which in places forks or branches. In the southern part of the

mine there appears to be one 

large body of pegmatite, which, 

with the inclosed horses of gneiss, 

is from 50 to nearly 100 feet 

thick, but to the northeast it has 

branched out into at least three 

smaller beds, which have been 

prospected by open cuts.

The pegmatite varies greatly 

in texture and composition. In 

the southern part of the workings it contains plentiful biotite, 

much of which is intergrown 

with muscovite. In part of the 

rock exposed in the open cut to 

the south crushed biotite crystals 

from a quarter of an inch to an 

inch thick and several inches 

wide are so abundant as to make 

the pegmatite very dark gray. 

Mr. Davis states that biotite was 

so plentiful and " so closely inFIGUKE 20. Plan of the Davis and Rhoda termixed with the white mica in

mines, 2\ miles north-northwest of Gil- places in the stopes as to Cause 

H., showing , , i i L- trouble in mining and separating 

them. The muscovite mica is of 

good quality and has a clear light-rum color. A little beryl, greenish 

apatite, and black tourmaline were observed around the dumps. 

Quartz occurs in large, massive segregations, one of which is exposed

Approximate scale 

o so 100 200 300 Feet

sum, Cheshire County,

part of geology.

N.

south of the engine house.

RHODA MINE.

The Rhoda mine, called the Tripp No. 2 in a former report,52 is 

a continuation of the Davis mine across the road to the northeast 

and has been worked by a series of open cuts along the outcrop. (See

K Sterrett, D. B., Some deposits of mica in the United States: U. S. Geol. Survey 

Bull. 580, p. 93, 1915.
NEW HAMPSHIRE. Ill

fig. 20.) The open cuts continue as stopes to varying depths where 

the pegmatite was richest in mica. The southern part of the workings had been cleaned out and was in operation at the last visit 

(October, 1914). This part consists of an open cut of irregular 

shape about 25 feet across and 30 feet deep, with a stope 6 feet wide 

carried 20 feet deeper. The mine is equipped with an engine, derrick 

hoist, pump, compressor, and air drills. Plate XIV, .A, is a view 

looking N. 15° W. across the open cut and deep stope.

The body of pegmatite is large, probably nearly 75 feet thick. 

Most of the work has been done along the northwest or footwall 

contact, where a rich streak of mica was found. This streak ranges 

in thickness from 2 to more than 4 feet and has a somewhat 

sinuous northeastward trend and an irregular southeasterly dip. 

The stope opened at the time of visit was very rich in mica. Many 

large crystals measuring from 1 foot to 2 feet across were exposed. 

Most of these were only 2 to 3 inches thick. Some of the crystals 

were arranged with cleavage perpendicular to the wall of the pegmatite; others were turned at different angles. A number of these 

mica crystals in the working face of the deep stope are shown in 

Plate XIV, B. The mica has a clear rum color and is of good 

quality. On the southeast side of the workings a large mass of 

quartz is inclosed in the pegmatite in contact with the mica gneiss 

country rock.

TBIPP MINE NO. 1.

The Tripp mica mine No. 1 is about a quarter of a mile north by 

west of the Island mine, or 2£ miles N. 20° W. of Gilsum. It has 

not been operated for several years, and when it was visited it was 

filled with water and badly overgrown with brush. The workings 

consist of an open cut run northward more than 125 feet long and 

20 to 30 feet wide. The waste and ore were removed by an inclined 

track at the north end of the cut. Some of the pegmatite was coarse 

grained and contained large quaftz segregations and crystals of potash feldspar more than a foot thick. At the north end of the open 

cut a tree had been recently uprooted, exposing a deposit of mica 

several feet across in the pegmatite. Some of the crystals of mica 

were 12 inches in diameter, and a few were seen that would cut into 

sheets measuring 4 by 6 inches. The mica has a clear rum color and 

is of fairly good quality.

ISLAND MINE.

The Island mica mine, 2 miles N. 20° W. of Gilsum, was worked 

long ago by James Davis. It is now owned by Watson Bros., of 

Boston, Mass., but has not been operated for several years. The 

workings consisted of three open cuts and a short tunnel. Two of
112 MICA DEPOSITS OF THE UNITED STATES.

the open cuts were at the east foot of a small knoll that stands about 

25 feet above the surrounding swampy ground. These open cuts 

were 20 and 25 feet deep but are now filled with water. The third 

cut was made back into the knoll at a level a few feet above.that of

the lower cuts but still 18 or 20 

feet lower than the summit of the 

knoll. (See fig. 21.)

The country rock is biotite 

gneiss, which contains much black 

tourmaline near the pegmatite. 

The gneiss has a highly varied 

strike and dip adjoining the pegmatite-, as shown by symbols in 

figure .21. It has been much 

folded and crinkled in places by 

the intrusion of the pegmatite. 

The pegmatite body is very irregular in shape but has a general 

Avesteiiy trend across the knoll. 

It incloses streaks of mica gneiss, 

and small stringers and bodies of 

it are intruded into the surrounding gneiss. North of the shop, 

where the rock has been stripped 

bare by glacial action, a number 

of small curved lenses or bulblike masses of pegmatite are 

exposed in the crinkled gneiss. 

Along the contact of the gneiss 

and the main body of pegmatite 

these small masses appear to have

been forced out into the gneiss, which has curved around them. A 

tongue or streak of mica gneiss included in the pegmatite extends between the two lower cuts and may have connected with a body of 

gneiss exposed in the bottom of the upper open cut.

The pegmatite contains large segregations of smoky, gray, white, 

and pale rose-colored quartz, some graphic granite, pockets or bunches 

of mica (both muscovite and biotite), black tourmaline, green apatite, 

a few red garnets, and numerous beryl crystals. The mica seen was 

mostly "bunchy," but of course the best had been removed in the 

last mining. It has a clear rum color and is of good quality. Mr. 

Davis reports a good yield of mica, with some large crystals, during 

his work at the mine. A few crystals of biotite are intergrown with 

the muscovite. The crystals of beryl, some of which are as much sis

Gneiss Strike 

and dip

FIGURE 21. Plan of Island mica mine, 2 

miles N. 20° W. of Gilsum, Cheshire 

County, N. H., showing geology.
NEW HAMPSHIRE. 113

_ Boiler 

house

a foot in diameter, are blue, blue-green, yellow-green, and rich and 

p#le golden yellow. Good gem beryl has been found, but most of the 

beryl is translucent or opaque. Small golden beryl gems of exceptional beauty have been cut from clear portions of. large crystals.

FRENCH MINE.

The French mine of the American Insulator & Mica Co. is If 

miles N. 25° W. of Gilsum, in the town of Alstead. It is an old 

mine, opened more than 50 years ago and worked successively by the 

discoverer, a man named Mitchell, by a Mr. Bowers, and for a long 

time by W. A. & C. H. French. The workings consist of a large open 

cut 60 yards long, 

30 to 40 yards 

wide, and 20 to 60 

feet deep, with 

smaller openings 

at the north end 

and a shaft or pit 

20 feet deeper 

than the bottom 

of the cut, or 80 

feet from the surface. Two steam 

drills are used in 

mining, and derrick hoists and 

an inclined track 

are . used to remove waste and 

mica from the pit.

A view looking 

3O° W n«TT>oc.

. UU VV . tlUlUbo

the open cut is

shown in Plate XV, A. The derrick hoists rock from the bottom of

the cut into the car at the foot of the incline track.

The country rock is mica gneiss with highly schistose layers. The 

gneiss strikes north to N. 30° E. and dips 60°-80° SE. The pegmatite occurs in a large irregular mass cutting the gneiss. Streaks 

or horses of gneiss and schist are inclosed in the pegmatite, retaining 

about the same strike and dip as the country rock. Two prominent 

horses of schist, which extend nearly across the pit, were left standing above the level of the adjoining floor. The relations between 

the pegmatite and gneiss walls and horses are shown in figure 22. 

The area of the pegmatite is larger below ground than at the surface, 

so that the walls of the cut show pegmatite below with mica schist

Dumps

100 ZOO 300 Feet Mica gneiss above o

and pegmatite below V ______________ 

in walls of open cut 

FIGURE 22. Plan of French mica mine of American Insulator

& Mica Co., 1§ miles northwest of Gilsum, Cheshire County,

N. H., showing geology.
114 » MICA DEPOSITS OF THE UNITED. STATES.

or gneiss above. Both the gneiss and pegmatite are somewhat 

altered by weathering, but in places the pegmatite is fresh and 

hard. The feldspar of the pegmatite is mostly the potash variety, 

and has perthitic texture. Quartz does not occur in large segregations, and only a few small masses were observed. Black tourmaline is abundant in places and, near the bottom at the south 

end of the open cut, crystals 8 inches or less in diameter are associated with the mica. The mica is scattered irregularly through the 

pegmatite, there being some richer places, chiefly along the mica 

schist inclusions or walls. Mica crystals of various sizes, some 18 

inches or more in diameter, were abundant in the working face at 

the south end of the cut, below and south of the end of the incline. 

The mica has a good cleavage with very elastic sheets. Some of it 

is slightly smoked or dusted with minute particles between the 

laminae.

Open cut

A

Biotite gneiss

Pegmatite

0 .10 20 80 40 50 100 FEET

FIGURE 23. Plan (A) and cross section (B) of Keeiie Mica Products Co.'s mine, 1 mile 

northwest of Gilsum, Cheshire County, N. H., showing geology.

KEENE MICA PRODUCTS CO.'S MINE.

ft

The mine of the Keene Mica Products Co. is 1 mile N. 40° W. of 

Gilsum. It has been worked by an irregular-shaped open cut 65 

feet long and 15 to 25 feet wide, shown in figure 23. This cut is 

about 25 feet deep along the east side, where there is a slight overhanging wall, and 15 feet deep on the west side at the north end. 

The country rock is biotite gneiss carrying considerable tourmaline 

near the pegmatite. The gneiss strikes N. 15° W. and has a high 

but variable dip to the east. The pegmatite mass is large and 

irregular in shape. In part it is conformable with the foliation of 

the inclosing gneiss and in part it cuts the foliation. The relation 

between the gneiss and pegmatite exposed in the north end of the 

cut is shown in the cross section in figure 23. From the 'south side 

of the northern part of the open cut. a trough-shaped horse of
NEW HAMPSHIRE. 115

tourmaline-biotite gneiss, 12 to 15 feet thick, with pegmatite on 

each side of and below it, extends southward for more than TO feet. 

Apparently this horse did not connect with the deeper roll of the 

gneiss on the north end of the cut shown in the cross section. The 

pitch of the pegmatite and gneiss contact along this side of the cut 

is about 15° N. This would mean that the surface relation restored 

would give the approximate contacts shown by the dotted lines in 

the plan, and such were the original conditions as reported by the 

miners. Plate XVI, A, is a view from the middle of the north side 

of the open cut looking south. The sequence from west to east is 

plainly shown that is, the biotite gneiss wall on the west, pegmatite, the horse of gneiss shown in figure 23, more pegmatite opened 

by a cut 25 feet deep, and the gneiss wall on the east in the open cut. 

The pegmatite is of diverse texture, some parts showing a very 

coarse crystallization with feldspar crystals 2 to 3 feet across and 

large quartz segregations. A little graphic granite was observed. 

The mica is richest near the hanging wall of the pegmatite, in streaks 

3 to T feet thick. A thickness of 6 to T feet has been removed in 

mining, and in places the work has been extended to other parts of 

the pegmatite where pockets of mica were found. A mica streak, 

part of which has been worked, occurs along the west side of the 

horse of biotite gneiss. The face left on the pegmatite at this point 

shows a quantity of smaller sheet mica which will pay to remove. 

Plate XVI, B, shows this local enrichment of mica near the biotite 

gneiss. The mica obtained from this mine has a clear light rum 

color and is of good quality. A little biotite is associated with the 

muscovite. .

\

The mine is equipped with a Sullivan gasoline-engine compressor, 

with two hand drills and one large drill. The mica is hauled to the 

company's plant at Keene, where numerous mica products are manufactured 'for the glazing and electric trades.

JEHIAL WHITE MINE.

The Jehial White mine is 1 mile south of Gilsum on the east side 

of the State road leading to Keene. The mine was opened about 8 

years ago by James Davis and has been worked intermittently since. 

At the time of examination (October, 1914) Mr. White was operating 

under contract with the Keene Mica Products Co. The workings 

consist of an irregular-shaped open cut about 90 feet long, 15 to 30 

feet wide, and 5 to 25 feet deep made in a S. 25° W. direction into a 

hillside. Much of the lower end of the cut has been filled with waste 

from the upper end of the workings. The shape of the open cut is 

shown in figure 24. The equipment consists of a shop, gasoline engine, air compressor, drills, and a derrick hoist.
116 MICA DEPOSITS OF THE UNITED STATES.

The country rock is highly foliated biotite gneiss, which strikes 

about north and dips from 30° to 60° E. The pegmatite cuts the 

gneiss very irregularly, parallel with its bedding at one place and 

across it at another. Strikes from north to northeast and dips from 

20° to 60° east and southeast were measured on the pegmatite. The 

thickness of the pegmatite is difficult to determine, as it forks in 

some places and includes horses of gneiss in others. In the exposures 

available for examination it ranges from 1 foot to 8 feet in thickness, 

these measurements not including large horses of gneiss. The texture is moderately coarse. Quartz occurs in segregations from 3 to 

12 inches thick. The feldspar is chiefly a plagioclase. Black tourmaline is rather plentiful. A 

little biotite and some beryl 

were observed. The beryl is 

opaque to partly translucent 

gray, yellow, and aquamarine 

green. The mica has a fine 

clear rum color and good 

cleavage. Most of the crystals found during 1914 were 

less than 10 inches in diameter, but Mr. Davis is reported to have obtained some 

larger sheets in working the 

lower part of the quarry.

NIMS MINE.

A mica deposit on the land 

of E. S. Nims, half a mile 

north of Sullivan, was operated a few years ago by a 

mica company of Keene. 

Two open cuts were made, 

one 30 by 35 feet across and 

14 feet deep and a smaller one a few feet to the north. A gasoline engine and air compressor with two air drills were used in quarrying. 

The country rock is porphyritic biotite gneiss, which strikes north and 

has a variable easterly dip. The pegmatite cuts across the gneiss with 

a strike of N. 65° E. and a dip of 20° SE. along the southeast contact. 

The northwest contact is not exposed. A horse of mica gneiss is 

inclosed in the pegmatite a few feet northeast of the workings.

The texture of the pegmatite is very coarse, some of the crystals 

of potash feldspar measuring 4 feet across, all clean feldspar. Gray 

and smoky quartz occurs in irregular masses. The mica was scattered irregularly through the pegmatite, but in one place a streak or

Contour interval 25 feet 

» y4 Strike and dipof strafa

FIGURE 24. Plan of Jehial White mica mine, 

1 mile south of Gilsum, N. H., showing part 

of geology.
NEW HAMPSHIRE. '

pocket of light-green wedge, A, and fishbone mica wag encountered. 

About 5 tons of mica is reported to have been taken out, some of which 

would yield good sheets. Among the associated minerals in the pegmatite, observed chiefly on the dump, were triphylite, beryl, black 

tourmaline, and pyrite. The triphylite occurs in grayish masses 

several inches across, with blue streaks, due to alteration products, 

along the cleavage faces. The beryl crystals are opaque, are yellow - 

ish or greenish gray, and some of them measure as much as 12 inches 

in diameter. Several hundred pounds could easily be gathered from 

the dumps.

PRICE PROSPECTS.

Several prospects 1£ miles west of East Sullivan were opened in 

1912 and 1913 by James W. Price. The principal one is along the 

edge of swampy ground, where a large mass of pegmatite crops out 

to a height of 15 to 18 feet above the ground. This mass strikes about 

north and is over 40 feet across. The working is on the west side 

of the mass and consists of an open cut 35 feet long and 4 feet deep. 

Water causes much trouble in the work. The east wall of the pegmatite is mica gneiss. The texture of the pegmatite is very coarse 

in places, the quartz segregations being several feet across and the 

crystals of potash feldspar 1 to 2 feet thick. The mica is richest 

along the west side of the pegmatite in a streak about 4 feet thick. 

It has a clear light-rum color and excellent cleavage. Six tons of 

run-of-mine mica is reported to have been removed from the cut, 

some of which would yield perfect sheets several inches across. 

Small crystals of beryl were observed in and adjoining some of the 

masses of quartz in the pegmatite.

About 250 yards to the south another open cut, 20 feet long, 12 

feet wide, and 8 feet deep, had been made in a pegmatite outcrop. 

The pegmatite trends northward. Crystals of potash feldspar more 

than a foot thick were encountered in the pegmatite. The mica has 

a clear light rum color and is of good quality. About 2 tons of mica 

is reported to have been removed, including one good crystal weighing 60 pounds.

About 200 yards farther south much mica has been found in a 

deposit of loose material consisting of fragments of pegmatite, 

feldspar, quartz, and earth. The mica is of good quality, and some 

fair-sized plates are reported to have been found. This deposit 

probably represents a bank of glacial drift consisting of material 

scooped out of a pegmatite mass not far distant, though it may be 

pegmatite decomposed in place, or waste from older workings that 

have been covered over or filled. 

111375 23 9
118 MICA DEPOSITS OF THE UNITED STATES.

BROOKS PROSPECT.

A mica prospect was opened in the spring of 1913 on the land of 

Charles Brooks, If miles west of East Sullivan. The prospect lies 

in gently sloping ground and consists of an open cut 45 feet long, 8 to 

10 feet wide, and 4 to 10 feet deep, of the shape shown in .figure 25. 

The country rock is grayish muscovite-biotite gneiss striking north 

and dipping east. The pegmatite has a northeast strike in part 

of the open cut, but forks, one branch going north and the other 

(not developed) east. The contact of the pegmatite and gneiss on 

the southeast side of the cut dips TO 0 NW. More pegmatite crops 

out about 30 feet northeast of the open cut. Much of the pegma-

, ^ tite is only medium 

\ .Sp^X grained, but in 

V\ places the texture is 

 --'' coarse. It is composed of a rather 

even mixture of 

potash feldspar, 

quartz, and mica, 

including a little 

biotite, with variable quantities of 

black tourmaline. 

The mica has been 

found in crystals 

measuring as much 

as 10 inches across. 

East Some of the crystals 

show wedge, A,~or 

hair-lined structure, and others split smoothly. The color is light 

rum. Sheets 3 by 4 inches could be cut from some of the rough 

crystals seen. More than 3 tons of rough run of mine mica is reported to have been taken from the open cut.

GRAFTON COUNTY. 

GENERAL ELECTRIC CO.'S MINE.

A mine has been operated since 1911 by the General Electric Co., 

of Schenectady, N. Y., about half a mile west of West Rumney 

(Swainsboro station on the Boston & Maine Railroad). The deposit is in the south side of a small hill and about 75 feet above a 

stream. The position of the workings and the surrounding geologic 

features are shown in figure 26, A. The trimming plant is at the 

foot of the hill.

FIGURE 25. Plan of Brooks mica prospect, 

Sullivan, Cheshire County, N. H.
NEW HAMPSHIRE. 119

Boulder or 

outcrop of 

pegmatite

Approximate scale 

o 25 so 75 100 Feet

FIOUHB 20. Plan of General Electric Co.'g mica mine, near Swainsboro, Grafton Couniy, 

N. H. A, Position of workings and geologic features; B, cross section of vein at A.-B\ 

C, cross section of vein at C-D.
120 MICA DEPOSITS OF THE UNITED STATES.

In October, 1914, the work consisted of open stopes and open cuts 

through a distance of about 200 feet in an irregular east by north 

direction. The open cut ranged in width from 6 to 20 feet, conforming to the width of the " vein." The stopes were carried to a depth 

of more than 100 feet but had been filled up to the 60-foot level, 

for the vein was poor in the bottom. The stopes exposed ranged 

in width from 4 to 12 feet, increasing in width upward at some 

places into the open cut. The deepest work was done at the highest 

point of the outcrop and was carried about 65 feet along the vein. 

The open cut extended about 50 feet west by south from the west 

end of the deep stope and nearly 100 feet east by north- from the 

east end down the hillside toward the trimming plant.

The country rock near the pegmatite is quartz-biotite-muscovite 

gneiss. A few yards to the northwest the gneiss contains also fibrolite. The gneiss has been strongly folded near the mine and has a 

somewhat variable strike, approximating N. 65° E., and a dip of 

60° NW. Much of the pegmatite is nearly conformable with the inclosing gneiss, especially where it occurs in the sheetlike mass, but 

in places it is forked, so that part of it cuts the schistosity of the 

gneiss. The pegmatite pinches down to a thickness of about 2 feet 

at the west end of the open cut and swells to about 20 feet at the 

:fork shown at C-D in figure 26. The average thickness is about & 

-feet. Details of two forks in the pegmatite occurring at A-B and 

{J-D of figure 26, A, are shown in figure 26, B and C. The fork of the 

^pegmatite near C-D in the open cut is also shown in Plate XVII, A. 

The horses of gneiss included between the forks of the pegmatite 

widen to the east, which shows that the forks pitch to ^e east. Even 

where the pegmatite does not fork it has local variations in stripe 

and dip due to warping of the sheet.

The pegmatite has a varied texture, some of it being very coarsegrained and some finer, resembling coarse granite. In places along 

the contacts where the texture is not coarse there is a partial banding of streaks rich in mica with mixed quartz and feldspar. In the 

main working a " vein " along the hanging wall was richest in mica. 

1 foot to 3 feet thick, but bunches or pockets of good mica were also 

found scattered through the mass of the pegmatite. The " vein " was 

richer in the large stope, from the surface down to nearly 100 feet 

deep, than in the other parts exposed by stripping and open-out 

work to the east. The mica has a clear light rum color, and much of 

it is in clean crystals with good, flat cleavage. Some of the crystals 

are 2 feet or more in diameter, and the best of them make fine 

stove mica. Fragments of beryl crystals 2 to 10 inches in diameter 

were seen on the dump. These crystals had well-defined hexagonal
NEW HAMPSHIBE. 121

shapes but were opaque and were of dull grayish-green to yellowish 

colors.

The General Electric Co. has equipped a trimming plant near the 

mine for preparing the mica in the forms desired for use at the main 

works in Schnectady, N. Y., and by the glazing trade. Machine 

trimmers were used first but were abandoned later, as they did not 

leave the rough-trimmed mica in favorable condition for splitting 

and other treatment in the course of manufacture. Power punches 

are used for making disks and washers. A gasoline engine and 

dynamo supply the power 

to the motors operating 

the mill machinery and 

the electric-power drills 

used at the mine.

WHEAT MINE.

A mine was worked 

some years ago on the land 

of Lon Wheat, about 1£ 

miles northeast of West 

Rumney on the northeast 

side near the summit of 

the divide northwest of 

Rattlesnake Mountain. 

Open-cut work 150 feet 

long, 5 to 10 feet deep, 

and several feet wide was 

done as shown in figure 27. The entrance to the open cut was made 

through fibrolite mica gneiss which strikes N. 20° E. with a high 

southeast dip. The workings were overgrown by,vegetation and the 

rocks in the sides of the open cut were exposed at but few places. 

Pegmatite is exposed on several sides (see fig. 27) and the open cut 

was probably made in one large body of pegmatite.

Little mica was seen in place, but some left in the shop near the 

mine is light greenish and clear. The shop had been equipped with 

shears and wooden templets or patterns for trimming the mica.

. BELDEN MINE NEAR WEST RUMNEY.

Several prospects were opened by the Belden Mica Co., about half 

a mile north of West Rumney on a small glaciated plateau that 

stands about 150 feet above Bakers River, in the valley of which 

West Rumney is situated. The country rock is fibrolite-mica gneiss, 

which has a general north to northeast strike and a high east to 

to southeast dip. A number of masses of pegmatite crop out near

Approximate scale 

o 25 so 75 Feet

FIGUHE 27. Plan of Wheat mica mine, West Rumney, Grafton County, N. EL, showing geology.
122 MICA DEPOSITS OF THE UNITED STATES.

the prospects, a few of which have been opened. Most of these 

masses have a general northeast strike.

The main working consists of an open cut 15 feet wide and 20 

feet deep in the southwest face of a small, steep hill and a 15-foot 

tunnel driven northeast from the inner end of the cut. The mica 

gneiss wall rock at this prospect contains crystals of black tourmaline. The pegmatite is large and is irregular in shape, cutting across 

the bedding of the gneiss through most of its course. The pegmatite 

is very coarse grained, the segregations of feldspar and quartz being 

2 to 3 feet thick. Little mica was left in the dumps or seen around 

the workings.

HERBERT PROSPECTS,

Several mica prospects have been located on the land of Henry 

Herbert, about three-quarters of a mile northeast of West Eumney. 

on Rattlesnake Mountain. W. D. Stinson, who has an interest in 

these prospects, has done a little work on them. The most promising of these prospects consists of a ledge of pegmatite more than 

20 feet thick, which outcrops in a northeasterly direction around the 

mountain side and from which large blocks have broken off and slid 

down. One block 20 feet thick, which lies about 30 feet below the 

ledge, contains a large proportion of mica between massive quartz 

and finer-grained pegmatite. The quartz segregation is 2 to 3 feet 

thick and lies between the mica and a mass of coarse orthoclase or 

microcline feldspar crystals and graphic granite. Some of the crystals of mica are as large as 10 inches in diameter and 7 inches thick. 

They are bunched together in an exposure several feet long and 2 

feet wide. Some biotite in thin sheets nearly 12 inches across is 

included in the mass of muscovite.

The part of the ledge from which this block of pegmatite has been 

detached is covered with soil, but if the mica continues into it prospecting would probably locate the deposit easily. Exposures in the 

main ledge do not show deposits so rich in mica, possibly because the 

lower part of the ledge, which is largely concealed by soil, is the 

mica-bearing part. Mica crystals are seen in some of the other 

masses of pegmatite that crop out on the hillside.

The country rock near the prospects is fibrolite-mica gneiss, which 

strikes north by east and has a high easterly dip. A little hornblende 

gneiss is interbedded with the fibrolite gneiss.

WHICHER & PILLSBTTRY PROSPECT.

A prospect has been opened by a few blasts on land owned by 

Whicher & Pillsbury, 2f miles S. 20° W. of the village of Wentworth, 

in the town of Wentworth. The prospect is on the steep slope of the
NEW HAMPSHIRE. 123

southeast end of a hill or small mountain that rises about 1,050 feet 

above sea level. An outcrop of pegmatite which cuts biotite granite 

gneiss extends N. 80° W. about 150 yards along the hillside. The 

mass of pegmatite has an average width of about 8 feet through 

most of its exposure but pinches to a mere seam toward the west. 

The pegmatite is moderately coarse grained, the crystals of orthoclase feldspar and the segregations of-quartz measuring 6 to 10 inches 

across. Crystals of mica are plentiful in the outcrop, but most of 

them are less than 4 inches across. A few crystals that measured 

8 to 10 inches and one over a foot across were seen.

McGINNIS AND WHICHER & PILLSBURY PROSPECT.

Another prospect nearly half a mile southeast of the Whicher & 

Pillsbury prospect or 3 miles S. 18° W. of Wentworth crosses the 

boundary line between the land of Elias McGinnis and that of 

Whicher & Pillsbury. The prospect is in a small knoll close to a 

brook, about 400 feet lower than the Whicher & Pillsbury prospect. 

:A little open-cut work has been done in places along an exposure of 

pegmatite about 100 feet long and 8 feet thick. The pegmatite cuts 

biotite granite gneiss with a strike of N. 60° E. and a vertical dip. 

The pegmatite contains quartz segregations or lenses of quartz 1 foot 

to 15 feet long and as thick as 2£ feet, chiefly in its middle part and 

parallel with its walls. The feldspar is largely of the potash variety. 

Other minerals observed were a little black tourmaline, red garnet, 

biotite, and a number of crystals of beryl ranging in thickness from 

half an inch to 5 inches. Most of these crystals are opaque and 

aquamarine green, and a few contain translucent and small transparent portions. The pegmatite contains abundant crystals of mica, 

the largest 12 inches in diameter. The mica is clear light rum-colored 

and has good cleavage. The cleavage of the crystals near the walls 

of the pegmatite is nearly perpendicular to the walls.

SAUNDERS HILL PROSPECTS.

Several mica prospects have been found on the lands of Elias McGinnis and David Dow, on Saunders Hill, about 2 miles S. 60° W. 

of Wentworth. The country rock on this hill or mountain is biotite 

granite gneiss. Outcrops of pegmatite are numerous, and those at 

a few places contain enough mica to form promising prospects. Only 

a little blasting has been done in the outcrops and this not always 

at the best places.

At one place on the McGinnis property a thickness of about 4 feet 

of pegmatite from the hanging wall is exposed in a small bank for 

about 15 feet. Numerous crystals of mica, some as much as 10 inches 

across, are visible in the face of the rock. On the Dow place several
124 MICA DEPOSITS OF THE UNITED STATES

prospects have been blasted into a large blanket ledge of pegmatite 

with indifferent results. In one of these prospects crystals of beryl 

were found associated with small crystals of mica. In other outcrops of pegmatite on Saunders Hill crystals of mica ranging from 

a few inches to 10 inches across were seen.

VALENCIA MINE.

The Valencia mine is 2| miles N. 75° E. of North Groton, in the 

west side of a small mountain ridge called Fletcher Hill, about

1,400 feet above sea 

level. It is one of

Approximate scale

so 100 ISO 200 Feet 

1 i i i i

having been discovered about 1880 

by Capt. William 

Simpson and William Rice, of Bristol, N. H. Operations were carried 

on steadily for 10 

or 12 years, until a 

big cave-in of the 

workings occurred. 

The mine was operated on an extensive scale, and fortunately the large 

force of miners was 

out of the mine at 

dinner when the 

slide took place. 

The accident caused 

the loss of the power drills and other mining machinery and the 

closing of the mine.

The work consisted of an open cut run northAvard, more than 

150 feet long, 30 to 50 feet wide, and 10 to 40 feet deep, and, bf 

stopes run from the east side of the cut to a depth in places of 50 feet. 

Two long crosscut trenches, one at the north end and the other at 

the south end of the open cut, were run out to the hillside, where 

the waste rock was dumped. The dump piles are 50 to 60 feet 

high on their lower sides. Much waste rock was piled on the west 

side of the open cut and in the middle part, so that the full 

depth of the cut is not exposed. When examined the stopes were 

filled with water to the level of the lower end of the open cut. The 

shape of the workings and the relations between the gneiss and pegmatite are shown in figure 28.

dumps 

50 ft. high

frike and d!p of strata

FIGURE 28. Plan of the Valencia mica mine, 2| miles N. 75° 

B. of North Groton, N. H., showing geology.
1

i

NEW HAMPSHIRE. 125

Parts of the pegmatite are very coarse grained, the quartz occurring in irregular masses or segregations more than 10 feet across and 

the feldspar in crystals as large as 2 by 7 feet and some 6 feet square. 

The point projecting, into the open cut from the middle of the east 

side is composed largely of massive quartz. The feldspar is chiefly 

of the potash variety orthoclase or microcline. Among other minerals observed in the dumps were apatite and beryl. The beryl 

was fragmental and consisted of parts of crystals ranging from 

1 inch to 6 inches in diameter, some with a translucent aquamarine 

color. George F. Kunz 53 states that 100 aquamarine gems weighing 

from 1 carat to 4 carats were cut from beryl found at the Valencia 

mine in 1885. The mica has a fine clear rum color and good cleavage, and many large crystals are reported to have been found.

FLETCHER MINE.

The Fletcher mine is about 2£ miles east of North Groton, in a gap 

on the summit of Fletcher Hill ridge, about a mile southeast of the 

Valencia mine. The deposit was discovered after the Valencia deposit and was purchased by the General Electric Co. It was not in 

operation at the time of examination (October, 1914) but was ready 

to be worked when needed.

Three sets of openings have been made, one on the north side of a 

narrow glacial valley that cuts across the summit of Fletcher ridge 

and two on the south side. These workings are about 75 yards apart 

in a line that runs N. 15° E. to S. 15° W., and may be called for 

convenience the north, middle, and south workings. The glacial valley is a canal-like channel running S. 80° E., cut into the gneiss 

across the summit of the ridge. It is about 30 feet wide, has nearly 

vertical rock walls 10 to 20 feet high and steep slopes above, and 

holds a straight course for more than 200 feet across the bedding of 

the gneiss, crossing at an acute angle the general direction of the 

glacial striae of the region. It was probably formed by the plucking 

of great blocks of gneiss that lay between parallel joint planes by 

glacial ice. The position of the workings and the glacial valley are 

shown in figure 29.

The country rock is porphyritic mica gneiss containing fibrolite 

crystals in places. It has a general strike of about N. 15° E. and an 

approximately vertical dip, but it exhibits many small crumplings.

At the north working an open cut about 125 feet long, 10 to 20 

feet wide, and 5 to 18 feet deep extends N. 10° E. from the side 

of the valley. A 40-foot shaft was sunk in the east side of the open 

cut on the vein. The cut has not been opened through the full thickness 

of the pegmatite, which cuts across the gneiss with about a parallel

M Precious stones: U. S. Geol. Survey Mineral Resources, 1885, p. 439, 1886.
126 MICA DEPOSITS OF THE UNITED STATES.

strike but with a dip of 50° E. At the north end of the cut the " vein " 

of pegmatite forks around a tongue or horse of gneiss. This " vein," 

though rich in mica in most of the exposures, contains still richer 

streaks or patches, one of which lies along the west side of the cut 

near the north end and another on the east side between the 40-foot 

.shaft and the split in the vein at the north end. The crystallization 

of the pegmatite is fairly coarse, plagioclase feldspar occurring in

j

Approximate scale 

 o so 100 150 200 Feet

FIGURE 29. Plan of Fletcher mica mine, 2& miles east of North Groton, N. H., showing

geology.

crystals more than a foot across. A few crystals of beryl were observed in the pegmatite.

The middle working consists of an open cut 50 feet long, 15 feet 

wide, and 5 to 20 feet deep, and a 15-foot tunnel driven from the 

south end of the cut. The pegmatite is 15 feet thick and lies nearly 

in line with the vein of the north workings. It cuts the gneiss in 

about the same way as in the north working that is, with almost 

parallel strike and a dip of 50° E, A horse, or possibly the wall rock 

folded into the vein, is exposed in the bottom on the west side of the
NEW HAMPSHIRE. 127

cut. The inica is scattered through the whole of the pegmatite, but 

a streak richer in crystals lies along the east wall of the vein.

The south working consists of an open cut 65 feet long and 40 

feet deep. It is on a different "vein" from that exploited by the 

 other two workings, possibly on a fork from the main body of pegmatite, which crops out 35 feet to the west. The strike of the pegmatite in this working is about the same as in the others, but the dip 

was not exposed. The pegmatite to the west shows crystals of mica 

in its outcrop.

The mica from the Fletcher mine is clear, is of light rum color and 

has good cleavage. The mine can probably be made 'to yield a large 

output.

EASTMAN PROSPECTS.

Three mica prospects have been opened on the land of E. A. Eastman, about 2 miles north of North Groton. One of these is in a bank 

on the south side of a brook a few hundred yards northeast of the 

house, another is in the side of a mountain about a quarter of a mile 

to the north and 450 feet higher, and the third is a few hundred yards 

north of this and 200 feet higher, on the summit of a knob. Only 

small pits have been made at the two lower prospects, and there is 

an old shaft more than 50 feet deep on the summit of the knob.

The country rock around these prospects is mica gneiss, which in 

places contains fibrolite. The gneiss is strongly crinlded and has an 

approximately northeast strike and a vertical dip.

In the prospect on the brook a face 12 feet high had been opened in 

a deposit of pegmatite. Part of the pegmatite is rather fine grained 

and part is rather coarse grained, containing crystals of orthoclase 

feldspar more than 2 feet thick and irregular masses of quartz of 

about the same size. Most of the crystals of mica exposed were 

small, but one was 10 inches across though it was ruled into smaller 

pieces. The mica has a fine clear rum color. Among other minerals 

of the pegmatite were biotite, black tourmaline, lithiophyllite, and 

arsenopyrite or llo'lingite. A mass of lithiophyllite 8 inches across 

containing numerous patches of arsenopyrite was exposed in the 

pegmatite.

In the prospect on the mountain side a large body of pegmatite has 

been opened without exposing the wall rock. The crystallization is 

very coarse, some of the orthoclase crystals measuring as much as 3 

feet across. Except for surface staining, the mica is of good quality 

and has a clear rum color. The largest crystals seen were 8 inches 

in diameter.

Several ledges of pegmatite are exposed on the summit of the knob. 

The crystallization is in places fairly coarse, the rock containing 

large crystals of orthoclase and segregations of quartz. The ex-
128 MICA DEPOSITS OF THE UNITED STATES.

posures of mica are not unusual, for similar outcrops occur elsewhere 

in the region, but they may be worth prospecting.

UNION MINE.

The mine of the old Union Mica Co. is about 1 mile N. 10° E. of 

North Groton, on the eastern side of Bailey Hill. It ceased operations 

about 1888, and since then it has been idle and has become overgrown 

with brush and saplings. The workings consist of an open cut in the 

edge of a bench on the hillside about 150 feet long, 10 to 18 feet wide, 

and 5 to 35 feet deep, with a shaft, drift, and stopes in the bottom. 

The open cut is filled with rubbish and water to a depth of 20 feet. 

The shaft was 50 feet deep. Rock at first was carried from the open 

cut in a car to the lower dump, but later it was hoisted from the open

cut up an incline 

track and carried 

northward to a 

higher and larger 

dump. The shape 

of the workings is 

shown in figure 30.

The country rock 

is mica gneiss, which 

in some places contains fibrolite. It 

has a general northeast strike and an 

approximately vertical dip, and shows 

local contortions 

and crumplings, especially around the 

pegmatite. The pegmatite, which cuts the gneiss irregularly, strikes N. 60° E. and 

has a vertical dip. It varies considerably in thickness, pinching and swelling from 10 to 18 feet. The pegmatite pinches 

out abruptly at the southwest end of the cut, where the gneiss 

is folded around it. In the fork at the south end the pegmatite 

is 5 feet thick at the surface, and 3 feet thick at a depth of 15 

feet. Little of the pegmatite is exposed, but a study of the dumps 

shows that white quartz was encountered in large masses. Only a 

small proportion of pure orthoclase was removed in mining, most of 

the feldspar being plagioclase. The mica is of good quality, has a 

fine clear rum color, and is reported to have been plentiful in the 

" vein " and to have carried many large crystals.

-«- Strike of vertical bed

FIGURE 30. Plan of Union mica mine, 1 mile N. 10 

of North Groton, N. H., showing part of geology.

E.
NEW HAMPSHIRE. 129

About 300 yards southwest of the Union mine a series of prospects

-were opened on a large pegmatite outcrop extending about 100 yards 

I to the Holden property, near the summit of the hill. Some of the 

| outcrops of mica are fairly promising.

HOLDEN MINE.

A prospect was opened in 1914 on the property of Mrs. C. A. 

Holden, 1 mile N. 35° E. of North Groton. In October, 1914, two 

prospect pits about 70 feet apart from east to west had been dug 

on a hillside. Around the west pit the surface had been, stripped 

of soil over an area about 35 feet square, the stripping exposing 

pegmatite composed of coarse crystals of feldspar, massive quartz, 

and crystals of muscovite and biotite mica, some intergrown, with 

parallel cleavage. The muscovite has a fine clear rum color. Other 

prospects have been located on the same property.

STINSON AND CRAIG PROSPECTS.

An outcrop of pegmatite on the land of W. D. Stinson, 1£ miles 

northwest of North Groton, contains numerous crystals of mica. 

This ledge crops out for 250 yards N. 20° E., extending from the 

public road up a low hill and along a glaciated ridge. Through most 

of the outcrop the pegmatite ranges in thickness from 4 to 25 feet, 

pinching and swelling approximately in conformity with the schistosity of the inclosing fibrolite mica gneiss.

The pegmatite contains irregular segregations of quartz, some of 

them 2 feet thick, and large crystals of orthoclase feldspar. It includes also horses of gneiss. A few rough crystals of beryl were seen. 

The mica occurs in bunches of crystals, chiefly near the segregations 

of quartz. Some of these crystals measure 4 inches in diameter.

Two prospects have been located on the land of George Craig, a 

quarter of a mile west by south of the Stinson prospect. At one of 

these prospects an open cut 50 feet long, 5 to 10 feet deep, and 10 

to 20 feet wide has been made in a southwesterly direction up a hill 

slope. The pegmatite is, in places, 40 feet thick and contains numerous segregations of white quartz and some orthoclase crystals as 

much as 2 feet across. Small crystals of mica are plentiful, and some 

bunched or solid mica was observed.

CHARLES DAVIS MINE.

The Charles Davis mine, two-thirds of a mile west of North 

Groton, was worked by the Belden Mica Co. The workings consist 

of an open cut 100 feet long, 12 to 18 feet wide, and 15 feet deep,

 driven south westward into a hillside, and a shaft at the southwest end 

of the cut. The country rock is fibrolito-mica gneiss, which strikes
130 MICA DEPOSITS OF THE UNITED STATES.

N. 45° E. and dips vertically. The pegmatite is conformable with 

the gneiss. It is the full width of the open cut except near the southwest end, where it pinches to 4 feet and passes under a cover of soil. 

The pegmatite is rather even in texture and contains segregations of 

quartz about a foot thick and crystals of feldspar several inches 

across. The mica, which was richest near the walls, occurs throughout the mass and is of good quality but was not obtained in sizes and 

quantity sufficient to pay the rather high cost of mining. Specimens 

of blue lazulite without crystal form were found in fragments of 

pegmatite.on the dump. This is an unusual occurence, for the ordinary matrix of this mineral is quartzite, kyanitic schist, or some other 

metamorphic rock.

MICA PRODUCTS CO.'S MINE.

Two deposits of mica a mile west of North Groton were opened 

in 1913 by the Mica Products Co., of Philadelphia. At one of these 

an open cut was being made southwestward into a steep hillside for 

a height of about 45 feet. The cut was carried back into the hill 

by benches and the waste rock was rolled to the bottom and carried 

off in mine cars to the dump. The country rock is mica gneiss, in 

places carrying fibrolite. It is cut by pegmatite striking N. 48° E. 

and dipping about 80° NW. The pegmatite ranges in thickness from 

8 to 16 feet and averages more than 12 feet. The mica is richest 

near the middle of the vein, but some is scattered through other 

parts of it. Much of the mica is rather small but of fine stove quality. 

It is of a beautiful clear rum color in sheets one-tenth of an inch 

thick. One crystal was found that weighed 24| pounds and would 

cut into sheets more than 6 inches square.

The other deposit lies a couple of hundred yards north and was 

being prospected by small cuts in an outcrop of hard pegmatite about 

50 feet wide. The pegmatite is inclosed in mica gneiss or schist and 

has a strike of N. 45° E. and a vertical dip. The mica obtained 

here has been exposed to the weather and is not so sound as that from 

the other working. It might improve with increase in depth, if the 

quantity is sufficient to pay for development. Crystals of pale-green 

beryl were found, parts of which were clear enough for use as gems.

PALERMO MINE.

The Palermo mine (formerly called the Hartford) is about 1| 

miles southwest of North Groton in one of the ridges on the northeast side of Bald Head Mountain. This mine is one of several large 

producers of mica that have been worked extensively in New Hampshire. It had long been idle until it was purchased by the General 

Electric Co. which started reworking the dumps and made an examination of part of the underground workings. To make this
NEW HAMPSHIRE. 131

examination the mine was unwatered to a depth of nearly 150 feet 

below the highest workings, or 60 feet below the bottom of the open, 

cut. The trouble with water was not great, for a 5-horsepower 

gasoline engine removed about 60 feet of water. In two weeks after 

pumping was stopped the water had risen only 10 feet and this was 

the condition of the mine at the time of the writer's visit, in October,. 

1914.

A description of this mine has already been published 54 from 

notes obtained during a previous examination, when the mine was

Outcrop Of 

pegmatite

Contour interval 25feet

FIGURE 31. Plan of Palermo mica mine, 1| miles southwest of North Groton, N. H., 

showing geology. See text for explanation of numbers.

idle and filled with water, and from information furnished by Mr. 

L. E. Brown, of Canaan, superintendent of the mine for nearly 20 

years during the previous operations. A few changes have been 

made in the description and diagram used in the previous report 

as a result of better information obtained during the last examination.

The mine is in a knob that projects southward from the end of 

a small ridge. The workings consist of an open cut (1, fig. 31) 100

64 Sterrett, D. B., Some deposits of mica in the United States: U. S. Geol. Surrey 

Bull. 580, p. 72, 1915.
132 MICA DEPOSITS OF THE UNITED STATES.

feet long, 40 feet deep at the end, and 20 to 30 feet wide, driven 

N. 10° W. into the knob. The bottom of the cut is about 90 feet 

lower than the summit of the knob. At the end of the cut there is 

a large tunnel or room (2), 50 feet long, with deep inclined stopes 

(7) extending from it to the northeast and east and a drift with 

stopes extending upward to the north; an upraise (3) connects with 

workings from the outcrop about 50 feet higher and to the west, 

where an open cut (4) 30 feet long has been made with drifts and 

stopes carried underground from it. Another open cut (5) 40 feet 

long and 35 feet deep had been made northeast of the main lower 

open cut and about 40 feet higher. From this open cut (5) an inclined shaft (6) was sunk that connected with the main stopes (7) 

of the mine at a depth of 4 feet below the bottom of the main open 

cut (1).

Incline tracks were run eastward and northeastward into the stopes 

and another track was run northward into the drift. A view from the 

entrance to the large room (2) looking northeastward down into the 

stopes (7) is shown in Plate XVII, B (p. 108). At the time of examination the greater part of the vein was stoped out from above the 

drift to the east to a depth said to be more than 300 feet, on an incline of about 35°. The mine had been stripped of all but a few pillars and was dangerous. One room stoped out was at least 60 feet 

long, 30 feet wide, and 35 feet high, and was without support or 

pillar. Hauling and hoisting were done by an engine in the inner 

end of the main open cut. All drill work was done by hand, mostly 

with single-hand drills. At one time 85 miners were employed and 

25 or 30 girls were kept busy sorting and trimming mica.

At the time of examination deeper mining had not been undertaken by the General Electric Co., but a stope that was extended back 

to the southeast end of the large room (2) located a promising pocket 

of mica, and work was probably continued there. Other operations 

were confined mainly to the dumps, which cover more than 2 acres 

of ground, to depths ranging from a few feet to 30 feet or more. 

Part of them have already been worked over, but a number of the 

older dumps are still untouched.

The country rock is fibrolite-mica gneiss and lumpy or porphyritic 

biotite gneiss, in which the lumps are composed almost entirely of 

bunches of muscovite mica. The strike and dip of the gneiss measured near the mine vary widely, owing to distortion during intrusion 

of the pegmatite. The pegmatite cuts across the country rock in a 

large, irregular-shaped mass, whose approximate outcrop is shown 

in figure 31. This outcrop indicates an oval or pipe-shaped deposit, 

but the workings below ground show that it has a greater elongation 

north and south on an east dip. The rock is so resistant that its outcrop forms a small knob on the end of the ridge. The texture of the
NEW HAMPSHIRE. 133

pegmatite is varied and is in places extremely coarse. Feldspar occurs in crystals and masses several feet across, and some of the irregular segregations of quartz are large. In places the " vein " carries 

much small mica mixed with feldspar and quartz. Large crystals of 

mica are reported to have been found in pockets through the vein, 

one crystal measuring 4 feet 2 inches long and 28 inches wide and 

another fine crystal with sharp prismatic outline and fairly smooth 

faces measuring 2 feet square and 2 feet thick. The mica has a 

beautiful clear rum color and good cleavage. The dumps from early 

mining will yield some small plate mica of good quality and a large 

quantity of mica of punch size.

Among interesting specimens found on the dumps were beryl and 

zinnwaldite mica. The beryl was mostly opaque and some crystals 

were 3 inches across. They were bluish to yellowish green, with 

translucent and small transparent portions here and there. One 

crystal of rough mica less than an inch across found on the dump was 

determined to be zinnwaldite by W. T. Schaller, of the United States 

Geological Survey. The sheets of this mica show a clear brown core 

and a greenish-blue exterior about the color of some indicolite tourmaline. These colors are arranged parallel to planes of crystallization, and the blue contains thin zonal growths of the brown. Mica 

with the two colors gives the reactions of zinnwaldite.

INDIA MICA CO.'S MINE.

The India Mica Co.'s mine is in the southeast corner of the town 

of Dorchester, near Bryant Pond, about 5f miles N". 40° E. of Canaan. 

The mine was closed in 1906 after several years of active operation. 

It had a good equipment, including camp, engines, and machinery. 

Two principal openings were made an open cut 70 feet long and 

20 feet deep north of the engine house and a cut 50 feet long opening 

into a stope 50 feet deep south of the engine house. Pillars were left 

in this stope and five tiers of floors were built with stulls and lagging. 

An inclined track extended from the engine house down into the 

stope for the removal of mica and waste rock.

The country rock is quartz-biotite schist, which strikes N. 20°- 

35° E. and has a steep west to vertical dip. The schist near the 

pegmatite contains much black tourmaline in small crystals. The 

pegmatite is approximately conformable with the inclosing schist. 

In the north working the formations have been kinked or folded. 

The pegmatite is in the main from 6 to 10 feet thick, and the entire 

thickness was removed in mining at the southwest end of the mine. 

At the surface the pegmatite bulges to 12 feet in thickness but^is 

poor in mica. At 50 feet below the surface the vein, it is reported, 

pinches down to 12 inches in thickness. The texture of the pegmatite

111375 23 10
134 MICA DEPOSITS OF THE UNITED STATES.

appears to be rather even. The feldspar is mostly oligoclase and: 

was not found in very coarse crystals. The mica has a clear lightrum color, and part of it is of good quality. It occurs in crystals,, 

some of which weigh 50 pounds. In the folded part of the pegmatite 

many of the mica crystals are twisted and of poor quality.

Two hundred yards north by west of the mine a prospect was 

opened on an outcrop of pegmatite 15 feet thick. Mica, most of it 

small, was found associated with large segregations of quartz. The 

pegmatite contains also black tourmaline.

During the earlier days of mining by the India Mica Co. the mica 

as it came from the mine was hauled to Canaan and there graded for

Approximate scale 

0 10 20 30 40 50 FEET B

FIGURE 32. Plan (A) and cross section (B) of Keyes mica mine, 4| miles northeast of 

Canaan, Grafton County, N. H., showing part of geology.

shipment. Later a plant was set up in Canaan and the mica was 

rough trimmed for the market.

KEYES MINE.

The Keyes mica mine is 4| miles N. 50° E. of Canaan, in thetown of Orange, on the east side of the north end of Tugg Mountain. 

The principal working was an open cut of about the shape shown 

in the rough plan in figure 32, and 5 to 18 feet deep. Most of the 

open cut was in pegmatite, but streaks or horses of the biotite mica 

gneiss country rock were encountered at the places shown. The full 

thickness of the pegmatite was not exposed but is probably at least 

50 'feet with the mica gneiss inclusions. One large horse of gneiss is 

10 feet thick but does not extend far into the pegmatite, as shown 

in the cross section (fig. 32). The inclusions all strike northeast, 

which is probably also the trend of the pegmatite. The texture of
NEW HAMPSHIRE. 135

the pegmatite is coarse in places, the feldspar crystals measuring 

a foot or two across. The mica is somewhat pocketed and appears 

to be richest near the contact with the mica gneiss. At the bottom 

and on the west side of the large horse of mica gneiss good mica has 

been left in the pegmatite. The mica has a clear light-rum color 

and some of it is of good quality. The pegmatite carries beryl, pieces 

of which were seen on the dump, and one crystal 8 inches across had 

been left in the rock. 

A few rough quartz 

crystals were removed 

during mining, but most 

of the quartz is massive.

SANBOKN MINE.

The Sanborn mica 

mine is on Tugg Mountain, about 3£ miles 

N. 70° E. of Canaan. It 

has not been operated 

for three years. The 

developments consist of 

an open cut of the shape 

shown in figure 33, A. 

This cut is about 100 

feet long, with an enlargement at the south 

end, and is 10 to 20 feet 

deep. The country rock 

is a highly foliated mica gneiss containing quartzose and micaceous 

layers and both biotite and muscovite. The gneiss strikes N. 10°-20° 

E. and has a high dip to the east. Several masses of pegmatite, whose 

surfaces have been rounded by glacial erosion, crop out on the summit 

of the hill. These masses are in part conformable with the inclosing gneiss but in places cut across its bedding. The mica has 

been obtained from a small body of pegmatite about 10 feet thick, 

which has branched out from a large mass of pegmatite into the surrounding gneiss and from around the end of the body of mica gneiss 

that is included between the fork and the main mass of the pegmatite. 

The inclosed body of gneiss is about 60 feet thick, and at the south 

end the contact has a pitch to the north of about 35°. Details of this 

contact between c and d of figure 33 are shown in Plate XVIII, A 

(p. 109). The horse of mica gneiss overlies the pegmatite unconformably, as seen on the right. The pegmatite is the lighter-colored rock 

rising above the water. The cross section in figure 33, B, shoAvs the relations between the pegmatite and gneiss. The pegmatite has an unB

FIGURE 33. Plan (A) and cross section (B) of Sanbo 111 mica mine, 3J miles N. 70° E. of Canaan, Grafton County, N. H., showing geology.
136 MICA DEPOSITS OF THE UNITED STATES.

even texture and in places contains segregations of quartz. More 

mica is exposed in the outcrop south of the open cut near the contact 

of the pegmatite at a place where the mica gneiss has been crumpled 

by folding. The mica seen around the mine was of fair quality, some 

having a clear rum color and some a slightly greenish cast.

BELDEN OR STANDARD MINE.

The Belden or Standard mine is on the south end of Tugg Mountain, 3 miles N. 75° E. of Canaan. It has been operated by several

persons and companies 

and worked by the 

Standard Mica Co. on 

an extensive scale. The 

last work was done by 

C. W. Bryant, of Lebanon, in June, 1913. At 

that time the mine consisted of an irregularshaped open cut or 

quarry about 250 feet 

long in a northerly 

direction, about 200 feet 

wide, and from 10 to 

45 feet deep. Another 

smaller open cut had 

been made to the south 

of the main quarry. 

The position of the 

openings, mine buildings, tracks, dumps, etc., 

is shown in figure 34. 

The quarry was worked 

to different levels in 

benches. At the south 

end of the main quarry 

two short tunnels were made. A view looking southwestward across 

the open cut is shown in Plate XVIII, B (p. 109).

The country rock is mica gneiss composed of quartzose layers and 

layers rich in biotite and muscovite. The pegmatite is a very large 

mass whose relation to the country rock is not exposed. The impression gained by examination of the workings is that of a thick bed 

with a northerly strike and a dip of 20°-30° E., but it is possible 

that the dip is more nearly vertical. The open cut is wholly in pegmatite except for a small horse of mica gneiss on the west side. This 

gneiss has been strongly metamorphosed and contains black tourFIQCRE 34. Plan of Belden or Standard mica mine, 3 

miles N. 75° E. of Canaan, Grafton County, N. H.
NEW HAMPSHIRE. 137

maline. It appears to merge into the pegmatite. The pegmatite

varies in texture and in places is very coarse. Feldspar crystals 1

' foot to 3 feet thick were seen, and quartz occurs in irregular segreV gations and veins, in one place 7 feet thick. Beryl crystals are

i rather common, and the mica and beryl are most plentiful around

the quartz masses. In general the mica is rather pockety, but a few

*, crystals occur scattered through the pegmatite, and to insure the

recovery of all this mica the whole of the pegmatite was mined by

the Standard Mica Co. This proved to be an extravagant method.

The later work by Mr. Bryant was directed only toward those parts

of the pegmatite found to be richest in mica.

The pegmatite is composed of two kinds of feldspar, microcline 

and albite. In places the microcline has formed a rough graphic 

intergrowth with quartz. Some of the albite occurs in rough crystals almost of the clevelandite type. Black tourmaline, bluish-green 

apatite, and opaque garnets are scattered through the pegmatite. 

The largest crystals of beryl are 10 inches in diameter and 12 

inches long. Probably several tons of rough opaque crystals could 

be gathered up around the mine. Most of the mica is small, less 

than 4 by 6 inches, but sheets 8 by 10 inches are reported to have 

been cut from the largest crystals. The mica, is of fair quality, 

showing shades of both rum and green colors.

Other mica prospects have been tested on the same property, one 

150 yards southwest, another about 300 yards southwest, and another 

250 yards north-northwest of the main mine. At the first of these 

the pegmatite is at least 40 feet across and carries a quantity of 

small mica. Along the west contact of the pegmatite the gneissic 

wall rock merges into the pegmatite as if by a fusion contact. At 

the second place an open cut 50 feet long was made on a vein of 

pegmatite 2£ to 6 feet thick, and another cut 45 feet long on another 

vein 1 foot to 4 feet thick, lying 60 feet to the west. These veins oi 

pegmatite are in part conformable with the inclosing gneiss, but 

one of them has a branch or fork cutting across the foliation.

HOYT HILL MINE.

The Hoyt Hill mine is 3 miles S. 75° E. of Canaan, near the summit on the west side of Hoyt Hill. The working consists of an open 

cut or shaft 20 feet across and reported to be about 50 feet deep, inclined to the north. It was filled with water at the time of examination, and only surface conditions could be studied. The country 

rock is mica gneiss composed of biotite and muscovite schists containing quartzose layers. Some of the layers contain black tourmaline. The schist layers of the gneiss are in places strongly folded 

and crumpled and inclose lenses and streaks of quartz, pegmatite,
138 MICA DEPOSITS OF THE tJiTITED STATES.

and granite. The strike is N. 30°~40° E. and the dip is rather variable. The pegmatite cuts through the gneiss in the form of a stock 

 or pipe. On the northeast side the pegmatite forks out into the 

gneiss. On the east side the gneiss has been crumpled by the intrusion of the pegmatite. Among the minerals observed on the 

dump were pinkish plagioclase feldspar, black tourmaline, and green 

apatite. The mica has a clear rum color, and crystals of good size 

are said to have been obtained.

PROSPECT NEAK ORANGE.

A mica deposit was worked on the road from Orange to Alexandria, about 3-| miles east of Canaan and half a mile southeast 

of Orange. Two open cuts and a short tunnel were dug. The cut 

near the road is reported to have been 30 feet deep but is now filled 

up. The one to the north is about 15 feet deep but is filled with 

water. The country rock is mica gneiss containing streaks of fine 

biotite schist. It strikes N. 10° E. and stands vertical. The pegmatite is irregular in shape and was not found in the northern open 

cut in line with the strike shown by the work near the road. Black 

tourmaline is plentiful in the pegmatite and occurs in crystals 4 

.inches in diameter. Very little mica had been left around the mine.

SUMMMIT MICA HIKING CO.

A mica prospect was opened about 25 years ago by the Summit 

iMica Mining Co. near the north edge of the town of Grafton, on 

the east side of the railroad, about 3 miles north of Grafton Center. 

No work had been done for many years prior to the time of examination, in October, 1914, and little could be seen then. An open cut 

35 feet long, 10 to 18 feet wide, and 10 feet deep to water had been 

made in a large pegmatite ledge that crops out for 150 feet east and 

west across swampy ground. This outcrop is 40 to 100 feet wide 

and stands 10 feet above the surrounding swamp. Most of the 

feldspar is albite. Small crystals of clear, light rum-colored mica 

were seen in the walls of the cut.

GRAFTON MICA WORKS.

The mine of the Grafton Mica Works is about 2 miles north by 

west of Grafton Center on the east side of the same mass of hills 

to which Isinglass Mountain belongs, at an elevation of about 1,150 

feet above sea level. The workings consist of several open cuts 

and a tunnel in a spur projecting northeast from the mountain side. 

One cut is about 30 feet square and from 5 to 10 feet deep and another is 40 feet long, 8 feet wide, and 30 feet deep in the inner end.
NEW HAMPSHIRE. 139

The other openings are smaller. The openings on the ridge are 

.about 60 feet higher than those in the tunnel below. The countyrock is biotite gneiss and carries abundant fibrolite in some beds 

and black tourmaline near the pegmatite. In the tunnel the gneiss 

strikes N. 30° E. and dips 65° SE. The mass of pegmatite is large, 

possibly 200 feet across the outcrop. Its relation to the gneiss is 

not well exposed, but the southeast contact strikes about N. 30° E. 

.and dips steeply. The texture of the pegmatite ranges from medium 

to very coarse grain. Masses of solid mica from 2 to 4 feet thick 

were seen in three places. Quartz occurs in segregations several feet 

across. The mica is reported to have been found in bunches or 

pockets several feet across, but none of these was left exposed in the 

working faces. Among the associated minerals black tourmaline 

and a few small crystals of beryl were observed.

BUGQLES NEW HILL MIKE.

The Kuggles New Hill mine is If miles N. 20° W. of Grafton 

Center, in the north end of a small ridge on one of the summits of 

Isinglass Mountain, at an elevation of about 1,375 feet above sea level. 

The mine was in operation when the atlas was prepared for Hitchcock's " Geology of New Hampshire," published in 1878, but was 

closed soon after that time, and but little work has been done since. 

The earlier .work was all open quarrying, but a little tunneling was 

done later. The principal work consists of an open cut 40 feet 

square, now filled to within 10 feet of the surface with rubbish. The 

last work in this cut consisted of a heavy blast which broke off great 

blocks of country rock from above that fell into the cut and concealed the working face. Three other large open cuts were made on 

the hillside about 150 feet southeast of the main cut, but the relations 

between the " vein " and the wall rock were not well exposed in these 

cuts either. The country rock consists, in part at least, of granite, 

which forms a cap rock over the pegmatite at the main quarry. 

The mine is reported to have yielded mica of fine quality and good 

sizes in the earlier workings, but later did not produce mica so good. 

The mica has a light rum color and good cleavage.

HAGGLES HIKE.

The Ruggles mine is in the south end of Isinglass Mountain, about 

1£ miles northwest of Grafton Center, at elevations ranging from 

1,300 to 1,450 feet above sea level. The workings cover a large area 

on a steep mountain side. They start from a break at the base of a 

steep slope and extend up nearly to the summit of the mountain, 

about 150 feet higher. The early workings consisted entirely of open 

quarries in the steep slope. These quarries were large, but some of
140 MICA DEPOSITS OF THE UNITED STATES.

Lower,

the lower ones are now covered by the dumps from those above. The 

later workings consist of large tunnels and stopes driven back into 

the mountain. Two sets of these have been made, one near the bottom of the steep slope and the other more than 100 feet higher and 

slightly east of the lower one. The dumps from the upper tunnels 

cover much of the old quarry workings, and these and the thick 

growth of vegetation over much of the hill make a careful study 

of the old part of the mine impossible. The dumps from the workings are extensive and contain a large quantity of mica that is

now merchantable. The relative positions of the workings in the hillside are 

shown in figure 35.

The upper workings consist of three partly connected open cuts from which 

tunnels are driven back into 

the mountain. The open 

cut on the west is 15 or 20 

feet lower than the others. 

Two large, irregular tunnels open into each other 

at intervals and form spacious rooms with down 

stopes on the west side. 

These tunnels are about 150 

feet long and might be considered one large tunnel with pillars 

left near the middle. Rooms 40 feet across and 20 feet high without 

support were made at two places, and into these rooms great blocks 

of rock have fallen from the roof. Views of the upper workings are 

shown in figure 36.

The lower workings consist of an open cut about 100 feet long, 50 

feet wide, and 25 feet deep in the inner end, with a tunnel and stopes 

driven about 160 feet farther. The workings have been cut back 

in a general northerly direction, as shown in figure 37. The inner 

end of the raised stope is more than 30 feet higher than the mouth of 

the tunnel. The main tunnel is really a large stope containing rooms 

25 feet high.

The country rock is mica gneiss in which biotite schist is prominent. Its banding is due chiefly to other layers, especially layers 

rich in quartz. Crystals of fibrolite were observed in the gneiss on 

other parts of Isinglass Mountain. Near the pegmatite the gneiss is 

more or less contorted and contains much black tourmaline. The 

country rock strikes N. 10°-20° E. and has a prevailing high easterly 

dip with local variations ranging from 60° E. to 70° W. around

100 FEET

FIGDKB 35. Sketch showing relative position of 

upper, lower, and old workings and dumps of 

Ruggles mica mine, on the south end of Isinglasa Mountain, Grafton County, N, H.
NEW HAMPSHIRE. 141

the pegmatite intrusions. The mass of pegmatite at the Ruggles 

mine is large and is presumably all part of the same intrusion. 

In the upper workings the pegmatite occurs as a large dome-shaped 

mass cutting across the gneiss, as shown in figure 36. On the 

sides the dip of the contact is steep and approximately conformable with the schistosity of the inclosing rock. The contact of the 

dome-shaped mass of pegmatite is irregular and pitches 20° S. in 

the workings on the surface. Back in the tunnel the pitch is lower, 

approaching the horizontal. Horses of tourmaline-biotite schist are 

inclosed in the pegmatite. Large segregations of quartz occur both 

in the open cut and in the tunnels. Large bodies of pegmatite rich 

in mica were evidently found where the stopes and rooms are large, 

and in some places

«Mica gneiss

good mica was left 

in sight in the pillars and walls. At 

least part of the 

feldspar in the mine 

is albite, and if 

there are other varieties they were not 

observed.

In the lower 

workings the pegmatite has a high 

dip to the west on 

the west wall, but 

elbows off abruptly 

to the east, cutting 

the bedding of the 

gneiss over the open 

cut, as shown in figure 37. A small body of fine-grained biotite granite cuts the pegmatite 

and gneiss on the east side of the cut, and from this point eastward the 

contract of the pegmatite is concealed. The contact of the gneiss and 

pegmatite over the workings pitches southward, or rises as it is followed back into the mountain. A horse of tourmaline gneiss is inclosed 

in the pegmatite at the place where the raised stope leaves the tunnel. 

Large masses of quartz occur in parts of the pegmatite, and one exposed in the bottom of the open cut (fig. 37) is about 20 feet thick. A 

body of solid mica about 35 feet long, with 8 maximum width of 6 

feet, lies on the west.side of the quartz. This body of mica is composed of many crystals that measure from half an inch to 2 inches 

in diameter, grown together at all angles. In the tunnel and stope a

PLAN

50 (00 Feet

FIGURE 36. Plan and cross section of upper workings of 

the Haggles mica mine,. Grafton County, N. H., showing 

geology.
142 MICA DEPOSITS OF THE UNITED STATES.

number of crystals of mica have been left exposed in the rock. Some 

of these crystals measure from 1 foot to 2 feet across but have been 

partly ruled into small sheets.

In some of the old quarry workings east and northeast of the lower 

workings and below the upper workings exposures of pegmatite show 

large quartz segregations and masses of feldspar with or without 

mica. At one place an empty cavity or pocket 2 feet in diameter was 

exposed in a face of pegmatite. The bottom of this pocket was lined 

with clusters of well-formed crystals of muscovite, the largest 2 

inches in diameter. Contacts of pegmatite and gneiss were observed 

at two places in the old workings.

EXPLANATION

CROSS SECTION

Approximate scale 

0 50 100 Feet

Tu n n e I 

entrance

PLAN '.: : 

FIGUKE 37. 1 lan and cross section of lower workings of the Ruggles mica, mine, Graftou 

County, N. H., showing geology.

The relation between the pegmatite in the upper, lower, and old 

quarry workings is not plainly visible, but the main mass of the 

pegmatite doubtless crops out in the area of old quarries and dumps, 

and the lower and upper workings are probably along the hanging 

wall of the deposit. The hanging-wall contact has a series of vertical stretches with nearly flat offsets to the east, so that it crops out 

northeastward around the mountain side and over the top of the 

mountain northeast of the upper workings. The contacts observed 

in the old quarries may be those of inclusions or horses of gneiss in 

the pegmatite.

The dumps covering the old workings are large, one of them forming a steep talus slope about 100 feet high. These dumps contain some
NEW HAMPSHIRE. 143

valuable mica that was once thrown away as waste, not only a large 

quantity of scrap mica suitable for grinding, but sheet mica ranging 

from punch size up to sheets that will cut 3 by 4 inches. Since 1912 

a part of the dumps have been worked over each year by a crew of 

several men. Unless a large force of men is employed it will take 

many years to work the dumps over thoroughly. The mica in these 

dumps is of good quality, not having deteriorated much by its long 

 exposure to the atmosphere. The mica from the Ruggles mine has 

a clear rum color 

and good cleavage. Some is 

quite flat and the 

remainder has 

slightly bent or 

curved cleavage 

faces.

Mica gneiss 

Pegmatite

Pegmatitic 

granite

KILTON MINE.

Roof of 

micagneiss

f

$. Dump

Fie ORB 38. Plan of Kilton mica mine, near Grafton Center, 

Grafton County, N. H., showing geology.

The M. M. Kilton mine is 1 

mile N. 50° W. 

of Grafton Center (Cardigan 

railway station).

T, i i 1U nas Deen m Operation in a small 

way for a number of years, and at the time of examination the 

prospects for opening a. good deposit of mica were bright. The mine 

is in a steep hillside at the south end of Isinglass Mountain, about a 

third of a mile south of the south end of the Ruggles mine. The 

workings consist of an irregular open cut about 25 feet deep with 

rooms from its sides and a stripped area with surface excavations on 

the hill above. The relations are shown in the rough sketch In 

figure 38.

The country rock is mica gneiss composed of beds of schist containing variable quantities of biotite, muscovite, and quartz as principal constituents, with accessory minerals. The gneiss strikes 

north by east and has a nearly vertical dip. The pegmatite body is 

large and varied from coarse-grained rock in the deeper workings 

to fine pegmatite granite carrying black tourmaline southwest of 

the mine. The excavations have developed a mass or roof of mica 

gneiss covering a part of the pegmatite on the east side of the mine. 

The lower contact between the pegmatite and the gneiss is approximately horizontal, with small rolls, but it is not conformable with 

the foliation of the gneiss. A small normal fault trending N. 10°
144 MICA DEPOSITS OF THE UNITED STATES.

E. and dipping 80° W., with a 3-foot downthrow to the west, cuts 

through the workings, as shown in figure 36. A view looking east 

by north in the open cut is given in Plate XV, B (p. 108). The lightcolored rock in the pillars is pegmatite and the darker rock overlying it is mica gneiss. The fault plane indicated in figure 36 is 

seen in the roof above the two men on the left. The mica occurs in 

streaks and pockets, and in the room at the north end of the open 

cut a large pocket or bunch of crystals was being removed at; thje 

time of examination. These crystals were 2 feet or less in diameter 

but were rather thin, some measuring only 2 or 3 inches. The 

quality of the sheet mica is good. Among the associated minerals of 

the pegmatite are black tourmaline (in crystals, some 4 inches in 

diameter), massive yellow beryl, and garnet.

EUREKA MINE OF M. M. KILTON.

A deposit of feldspar was opened under lease by the Eureka Mining & Milling Co. on the land of M. M. Kilton, at the north end of 

Ford Hill, 1£ miles west of Grafton Center. Some mica was found 

in the quarrying for feldspar but was reserved by Mr. Kilton. The 

deposit is on a steep north slope, about 1,450 feet above sea level. 

An open cut about 40 feet long, 25 feet wide, and 35 feet deep in the 

deepest part had been made in the hillside at the time of examination, 

in October, 1914. The rock is removed in a mine car and the feldspar emptied into wagons held in readiness or dumped on storage 

piles.

The country rock is mica gneiss, which in some beds carries fibrolite. It has a variable strike, ranging from east by north to northeast, and a dip of about 35° 'SE., but it has been locally distorted by 

the intrusion of the pegmatite. The pegmatite, which is approximately conformable with the bedding of the inclosing gneiss, swells 

from a thickness of about 15 feet at each end of the open cut to more 

than 20 feet near the middle. The feldspar occurs in large, fairly 

pure masses and contains only a small quantity of intermixed or 

graphically intergrown quartz. A little mica is scattered through 

the pegmatite, but most of it occurs as crystals in a streak 2 feet 

thick that lies about parallel with and 3 or 4 feet from the hanging 

wall. The largest of these crystals are 2 feet across, but they have 

been badly crushed and ruled into smaller pieces. The mica has a 

clear light rum color but is not of very good quality.

A promising exposure of feldspar has been opened in another cut 

about 75 feet northeast of the main working. The pegmatite exposed here contains a larger proportion of quartz than that in the 

larger cut but is of marketable grade.
NEW HAMPSHIRE. 145

Biotite granite

ALGER MINE.

The Alger mine is 1 mile S. 80° W. of Grafton Center near the 

summit of Alger Hill, at an elevation of about 1,500 feet above sea 

level. It is an old mine, worked first about 1875 by J. E. Martin 

and J. B. Page and later by the Grafton Mica Co. No work had 

been done for nearly 30 years prior to the examination in October, 

1914, and the mine was then thickly covered with brush. The workings consist of an open cut about 120 feet long, 30 to 45 feet wide, 

and 5 to 30 feet deep, with a room and stope on the north side and 

two small cuts on the south and southwest. (See fig. 39.)

The country rock is rather fine to medium grained biotite granite, 

which in places shows a gneissic structure. The gneissic phases 

strike N. 10° W. and have a nearly vertical to steep east dip. The 

pegmatite occurs as a 

bulging mass in the granite, starting with an outcrop about 20 feet thick 

at the northeast end of 

the cut and increasing in 

thickness southwestward 

to nearly twice the width 

of the open cut. The 

general relations between 

the pegmatite and granite are shown in figure 

39. The pegmatite is 

coarse grained and contains masses of quartz 

several feet thick and 

orthoclase crystals 6 feet 

across. Among the associated minerals are black tourmaline 

and beryl. The quartz ranges from opaque white to smoky and 

some is translucent. A few fragments of beryl crystals were seen 

on the dump, and the mine is reported to have yielded the largest 

beryl crystals in the world. F. W. Clarke 55 states that one crystal 

weighed more than 2 tons. Large crystals of mica were evidently 

found, for a remnant of one crystal that measured 2 feet in diameter 

remained in the wall. Several tons of scrap mica had been left 

around the mine, a little of which was suitable for cutting into small 

sheets or punching. The mica has a clear light rum color and a 

good cleavage.

Approximate scale 

^t-^j,^'' o 25 so____loo Feet

I) StriKe of vertical strata

FIGURE 39. Plan of Alger mica mine, near Grafton 

Center, N. H., showing geology.

K Mica: U. S. Geol. Survey Mineral Resources, 1883-84, p. 907, 1885.
146 MICA DEPOSITS OF THE UNITED STATES.

GAGE MINE.

An old mine owned by Fred Gage, on the northeast side of Prescott 

Hill, 2-J miles S. 85° W. of Grafton, was last worked 20 years ago,, 

and the workings were covered with vegetation when examined in 

October, 1914. An open cut 50 feet long, 18 feet wide, and 15 feet 

deep was made in a northeasterly direction along the hillside and a 

crosscut trench extending southeastward from it. The country 

rock is biotite granite gneiss. The mass of pegmatite is large and 

only its southeast wall is exposed. This strikes N. 35° E. and dips 

50° NW. Much massive quartz is piled on the dump. The feldspar 

is the potash variety, and it is reported that a quantity was shipped 

for use in making pottery. A little biotite was seen. The mica is

light greenish, and part of it is 

heavily ruled. Crystals as wide as 

12 inches, left in the rock, were cut 

by ruling lines into small pieces. 

In one place a mass of solid mica? 

composed chiefly of mica crystals 

from one-eighth to 1 inch across, 

is exposed in the walls of the cut. 

The large mica seemed richest near 

the footwall.

DE MOTT MINE.

The De Mott mine is 2^ miles 

east by south of Grafton. near 

the s crossroads on Prescott HilL 

It has been worked by an irregular-shaped open cut 30 feet across 

and 3 to! 15 feet deep. The country rock is highly foliated mica 

gneiss which has a north by west 

strike and a variable-easterly dip. 

At the place where the work has been done the pegmatite cuts 

across the foliation of the gneiss, but north of the mine the 

pegmatite ledge is more nearly conformable with the inclosing gneiss, as seen in the prominent exposure extending up the 

hill. The relations between the country rock and pegmatite 

and the shape of the open cut are shown in figure 40. The whole 

open cut is in pegmatite. Quartz occurs in the pegmatite in irregular masses or segregations several feet thick, and feldspar 

occurs in rough crystals 1 foot to 3 feet across. The mica is pockety 

or occurs in bunches near the quartz. Crystals of beryl, the largest 

a foot thick, are plentiful, and a ton or more of them has been laid 

out near the dump. Only scrap mica was left around the mine.

Mica gneiss

FIGURE 40. Plan of De Mott mica mine, 

on Prescott Hill, Grafton County, 

N. H., showing geology.
NEW HAMPSHIRE. 147 

HAILE OR BTTCKLEY MINE.

The Haile or Buckley mine is on the south side of Prescott Hill 

- 3 miles S. 65° W. of Grafton, at an elevation of about 1,900 feet 

above sea level. It was last worked by the American Mica Mining 

Co. but had been idle for several years preceding the examination in 

October, 1914. The mine was worked by an irregular-shaped open 

cut about 120 feet long, 60 feet wide in the widest part, and 10 to 

20 feet deep, with a little open stoping from the end and side of the 

cut. A 75-foot tunnel was driven from the hillside about 25 feet 

lower than the open cut, but it-failed to locate good mica. Two buildings in good repair remain standing near the mine.

The country rock is mica gneiss, which in some places carries fibrolite. The pegmatite is very large, and its contact with the mica 

gneiss wall rock is not exposed in the workings. A horse of gneiss 

is inclosed in the pegmatite at the mouth of the tunnel. The pegmatite forms a prominent rounded ridge that extends several hundred 

feet southwestward from the mine. A small diabase dike about 12 

inches wide cuts across the pegmatite in an easterly direction with a 

dip of 55° S. It is exposed both in the open cut and the tunnel.

The texture of the pegmatite is coarse. Quartz occurs in irregular 

segregations from 2 to 3 feet thick and orthoclase-feldspar in crystals 

2 feet across. A little biotite-mica occurs with the muscovite. Fragments of beryl crystals were seen on the dump, and one piece had a 

good clear aquamarine color but was somewhat flawed. The mica 

is clear rum color. Only small sizes were found around the mine,, 

but pieces of ruled crystals from 8 to 10 inches across were seen in 

the face of the workings.

UNITED MICA CO.'S MINE.

The mine of the United Mica Co. is on the southwest side of Prescott Hill, 2£ miles S. 50° W. of Grafton Center (Cardigan railway 

station). The company has a trimming house and plant with good 

equipment at Grafton Center. The mine has been worked by open 

cuts and tunnels from which stopes have been driven northeastward 

into the hillside. The main open cut is divided into upper and lower 

parts, the upper part being 15 to 20 feet higher than the lower. A 

large stope has been carried from it 200 feet to the northeast, a few 

pillars having been left for the support of the roof. An inclined 

track extends from the open cut into the stope to a depth of about 

30 feet in a distance of 100 feet, and the track is then run on a level 

100 feet farther, to the end of the stope. From the head of the incline the track leads to the dump, a distance of about 150 feet. Another small cut was made above the main open .cut to the north, and 

still another with a tunnel.and stope to the southwest. The vein
148 MICA DEPOSITS OF THE UNITED STATES.

has been opened to a depth of about 60 feet from the outcrop in the 

highest cut, on an incline of about 45° SE. There are local variations in the incline where the vein rolled.

The mass of pegmatite is variable in shape, pinching from a large, 

irregular body 15 feet or more thick in the open cut to a vein 1 foot 

thick in the bottom of the incline below the track. The vein strikes 

about northeast and dips 45° SE. The pegmatite has branches or 

offshoots extending into the quartz-biotite gneiss country rock and 

includes horses of the gneiss. In the lower part of the mine at the 

end of the stope the gneiss appears to roll, cutting the pegmatite off 

in a bulging mass. On the surface the pegmatite pinches out northeast of the workings. Further development would be required to 

learn whether the vein is thicker below the incline. The indications 

are that the body pitches southwestward down the hill, and if so a 

part of it has been removed by erosion.

Quartz is plentiful in the pegmatite in large masses or segregations. 

One lens-shaped body 6 feet in greatest thickness and 30 feet long was 

encountered in the stopes. The feldspar is chiefly plagioclase, and 

much of it has been stained a dull green. 0The mica was scattered 

through the vein but was richest near the quartz beds or lenses. In 

places the crystals were reported to be very plentiful. A little biotite 

mica is scattered through the pegmatite.

The mica has a clear rum color and is of good quality. Much of it 

was sold in the rough or after rough trimming until the company 

erected its own manufacturing plant at Grafton Center, where washers, forms for electric apparatus, and ground mica were produced. 

To cover mining costs, machinery being supplied by the company, 

the factory allowed the mine $60 a ton for run of mine mica.

A quarter of a mile northeast of the mine a large outcrop of pegmatite has been worked for feldspar. Boiler equipment, steam drills, 

etc., were installed for mining on a large scale. In places this pegmatite has large segregations of the constituent minerals, the feldspar 

crystals measuring 2 to 4 feet across, and irregular masses of quartz 

several feet thick. Parts of the pjgmatite contain black tourmaline, 

biotite-mica, and a little muscovite, as well as intergrowths of graphic 

granite, consisting of feldspar and quartz.

WILD MEADOWS MINE.

The Wild Meadows mine is 2-| miles N. 75° E. of Grafton. It is 

not now in operation but has been worked by an open cut nearly 175 

feet long and in places 20 feet deep, driven southwestward into a 

hillside, with a shaft and two pits to the southwest. The country 

rock is a rather coarse porphyritic biotite gneiss interbedded with 

mica schist, striking N. 20°-40° E. and having a vertical dip. The 

pegmatite ranges from 8 to 12 feet in thickness and has a slightly
NEW HAMPSHIRE. 149

sinuous course, approximately conformable with the inclosing gneiss. 

All the pegmatite was not removed by mining, masses of it being 

left in the sides of the open cut where it was folded or bulged out 

into the country rock. The texture of the pegmatite ranges from 

medium to coarse grained, some of the feldspar crystals being a foot 

thick. Both potash feldspar and albite, or soda feldspar, are present. 

The mica left exposed in the walls of the cut was in small bunches 

of crystals. The mine yielded a clear light-colored mica with a fine 

cleavage. Crystals of black tourmaline, beryl, and red garnets are 

scattered through the pegmatite.

MUD MINE.

The Mud mine is 2 miles S. 80° W. of Alexandria, in a steep hillside. It is now owned by the General Electric Co. but has not been 

operated for several years. It has been opened by a cut 150 feet 

long, 35 feet in greatest depth, and 30 feet wide, and by a tunnel 

driven 300 feet farther into the hill. Another open cut was made, 

in the hillside at a higher level, and a shaft TO feet deep sunk from 

it to the tunnel. The underground workings had caved badly 

and could not be examined, but some stoping is reported to have been 

done. Down stopes 10 to 15 feet deep are reported to have been 

made in the floor of the tunnel, where good mica was found. The 

country rock is coarse porphyritic biotite gneiss. The pegmatite 

strikes about N. 35° E. and has a vertical dip. A prospect crosscut 

trench shows that it is at least 50 feet thick near the end of the open 

cut. The pegmatite contains both plagioclase and potash feldspar, 

and the mica apparently occurs in a streak, 4 to 6 feet thick, along 

the northwest wall. Some of the mica is specked.

NEW HAVEN MICA CO.

The mine of the New Haven Mica Co. is on the summit of a mountain 2£ miles N. 70° W. of Alexandria, at an elevation of about 2,000 

feet above sea level. The mine has been idle for several years but 

was in good condition for examination at the time of visit in October, 1914, though a graded road that had been built to the property 

was in bad repair.

The workings consist of an open cut 75 feet long, 12 feet wide, and 

5 to 18 feet deep, driven S. 65° W. into the hillside, and a shaft 10 

feet deep, about 70 feet west of the end of the open cut. The rock 

has been stripped bare of moss and soil for about 100 yards west 

of the open cut along the summit of the mountain. The country 

rock is coarse granitic porphyritic biotite gneiss, containing phenocrysts of feldspar that attain a size of 1 by 2 inches. The mass of

111375 23 11
150 MICA DEPOSITS OF THE UNITED STATES.

pegmatite is 25 to 35 feet thick. It strikes about N. 75° E. and dips 

35° N". The rock is of very coarse texture and contains segregations of quartz as large as 10 feet thick and 30 feet long, orthoclasc 

crystals as much as 3 feet thick, and masses of nearly pure feldspar 

and graphic granite more than 10 feet thick. The mica occurs 

through the pegmatite in pockets or streaks ranging in size from 2 

feet by 8 feet to 6 feet by 20 feet. In places the pegmatite carries 

little mica, but some of the pockets are rich. Some crystals of mica 

exposed in the outcrop measure as much as 10 inches across and 4 

inches thick; others are less than 1 inch thick; and a few contain intergrowths of biotite. Irregular-shaped masses of white to gray and 

smoke-colored quartz and several opaque to translucent yellow, yellowish, and bluish-green crystals of beryl a quarter of an inch to 2 

inches thick were observed.

MONARCH MINE.

The Monarch mine is 3 miles N. 40° W. of Alexandria, on Fowlers 

River. Two deposits were opened here but are not now worked 

one in low ground on the north side of the river and the other on 

the hillside about 200 yards to the south, across the river. The 

northern deposit was opened by a shaft inclined about 30° from the 

horizontal to a reported depth of 200 feet, with drifts and stopes on 

the vein to the northeast. Tracks and mine cars conveyed the waste 

to the dump, which spreads over a considerable area in a flat field 

northwest of the mine. The country rock is porphyritic biotite gneiss, 

with phases that resemble metamorphosed porphyritic granite. 

Plagioclase is the principal feldspar of the pegmatite. Biotite and a 

little red garnet were also seen.

The other deposit was worked by a pit or shaft 25 feet across and 

reported to be 20 feet deep on the lower side. The bank on the upper 

side is 18 feet higher than the water which fills the pit. The country 

rock is the same as at the northern workings. The pegmatite was 

not exposed at the time of examination. A few red garnets and 

pyrite crystals were seen on the dump. The small mica left around

has a clear light rum color.

PATTEN MINE.

The old Patten mine, 4 miles N. 52° W. of Alexandria, had been idle 

for a number of years prior to the time it was examined in October, 

1914. The land is now owned by George Phelps, but the mineral 

right is held by another party. Two open cuts were run S. 60° W. 

up the side of ai hill, one cut at a level 20 feet higher than the other. A 

derrick was used in quarrying. The pegmatite outcrop is probably 

more than 100 feet wide, and no exposures of wall rock, were seen.
NEW HAMPSHIRE. 151

Segregations of quartz as large as 2 feet wide and 15 feet long and 

large crystals of orthoclase graphically intergrown with quartz occur 

in the pegmatite. The mica occurs in bunches and streaks of crystals 

from 1 foot to 6 feet across. The largest crystals seen were several 

inches wide and 5 inches thick. Much of the mica is ruled or,has A 

structure, but some would cut into good sheets. In some specimens 

biotite is intergrown with the muscovite. About 2 tons of mica suitable for cutting into small sheet or punch and for grinding as scrap 

were left at the mine.

RICH MINE.

The mine known as the J. Rich mine is 4 miles N. 38° W. of Alexandria. It has not been operated for a number of years, and at the 

time it was examined, in October, 1914, one of the openings was 

filled with waste from a higher opening and both were somewhat 

overgrown with brush. The deposit is in the side of a hollow and 

was opened by two small open cuts, one about 10 feet higher than the 

other, driven N. 20° W. into the hillside. The country rock is granitic 

biotite gneiss. It strikes N. 10° E. and dips eastward. The mass of 

pegmatite is large and is exposed for about 75 feet uphill from the 

workings. The rock is medium to coarse grained and contains segregations of quartz a foot or two across, crystals of orthoclase as much 

as 8 inches thick, and crystals of mica several inches in diameter. 

Some of the mica has a clear light rum color and good cleavage. The 

muscovite is accompanied by biotite, and a few small pinkish-red 

garnets were observed. Not much mica was exposed in the workings 

and little could be learned of the richness of the deposit.

SULLIVAN COUNTY. 

REYNOLDS BERYL AND MICA MINE.

A mine was opened on Springfield Mountain (Melvin Hill of 

Hitchcock's Atlas of New Hampshire), 2| miles S. 25° W. of Grafton, N. H., by F. H. C. Reynolds, of Boston. Two openings, about 

150 feet, apart, were made at the east side of the hill, about 400 feet 

above the valley. The main working is a quarry with a working 

face more than 80 feet long and 5 to 15 feet high running N. 60° 

W. along the hillside. The country rock is a quartz-biotite gneiss, 

which strikes north, has a nearly vertical dip, and shows some'folding. The pegmatite cuts across the foliation of the gneiss with a 

strike west by north and a dip of about 20° N. The contact with the 

gneiss is not regular but rolling, and a few smaller beds of pegmatite extend out into the gneiss parallel with its foliation. The 

bottom of the pegmatite is not exposed.in the workings. The rela-
152 MICA DEPOSITS OF THE UNITED STATES.,

tion between the gneiss and the pegmatite in the east half of this 

quarry is shown in figure 41.

The pegmatite is composed of potash, feldspar, quartz, mica, and 

other minerals. The feldspar occurs in large, pure crystal masses i r 

is graphically intergrown with quartz. The quartz, which is mixed 

through the pegmatite in grains and massive irregular segregations, 

is either white or smoky, and some of it is translucent. The deposit 

was worked for gem beryl only, but enough mica of a light rum color 

and good quality was found to help defray the cost of mining 

if it had been saved. Much biotite mica was observed on the 

dumps, and in many specimens biotite was intergrown with muscovite. Among other minerals in the pegmatite are black tourmaline, 

red garnet, green apatite, and beryl. Beryl was evidently rather 

plentiful, for many fragments of broken crystals of it were seen on 

the dumps. Some of the crystals measured several inches across, and

most of them were opaque or

Quarti-biotite gneis* . , , , »* T» only translucent. Mr. Key- 

- pegmatite nolds reports that in some of 

the crystals clear gem beryl 

A-, n ^ * .. « . was found, the golden variety FIGCRB 41. Cross section of east half of > > , & , 

quarry of Reynolds beryl mine, 21 miles S. 01 which Was especially finely

25° w. of orafton, N. H., showing relation colored. The colors observed

of pegmatite to gneiss.

in the fragments of beryl on

the dumps were light yellow to rich golden yellow, yellowish green, 

and light to dark aquamarine-green and greenish blue.

The other opening of the Eeynolds beryl mine is south of the main 

working. A pit was made in the pegmatite, cutting biotite granite 

and quartz-biotite gneiss. The pit and dump were overgrown with 

brush and little could be seen.

PROSPECT OF COLUMBIAN GEM MINING CO.

A prospect was opened for gem beryl and mica by the Columbian 

Gem Mining Co. on one of the summits of the northern part of 

Springfield Mountain (called Melvin Hill in Hitchcock's Atlas of 

New Hampshire), 2£ miles S. 40° W. of Grafton. More than 200 

feet of open-cut and trench work has been done, a shaft has been 

sunk, and considerable stripping of vein outcrop has been made on 

the summit of the mountain at an elevation of 1,750 feeb above sea 

level. The open cuts are 10 to 25 feet wide and 5 to 15 feet deep. 

The shaft is filled with water. No work had been done for a few 

years at the time of examination (October, 1914), but four buildings, 

in good repair, a quantity of punch and scrap mica, and a few rough 

crystals of beryl had been left at the mine. The position of the workings and stripped area are shown in figure 42.
NEW HAMPSHIRE. 153

Dump

The country rock is quartz-mica gneiss, which contains both biotite 

and muscovite. The gneiss is strongly banded and has been much 

folded and crumpled, so that definite strikes and dips could not be 

measured. It has been cut in several directions by pegmatite and 

associated granite. Some of the pegmatite shows steep to nearly 

vertical walls; the remainder apparently lies nearly flat or has a low 

dip, in relations which indicate that nearly vertical dikes acted as 

channels for forming the flatter beds. The associated granite, which 

merges into the pegmatite, is; chiefly fine-grained biotite granite. 

The pegmatite ranges from a granite-like rock to masses containing 

crystals of orthoclase 1 foot thick, segregations of quartz 3 feet 

across, and crystals of mica 8 to 10 inches in diameter. The arrangement and the position of the 

minerals in the pegmatite are 

very irregular.

The quartz of the pegmatite is white, gray, or smoky, 

and mostly opaque, but some 

is translucent and nearly 

clear. The muscovite has a 

clear rum color and part of 

it has good cleavage. Biotite 

is plentiful and some is intergrown Avith the muscovite. 

Black tourmaline occurs in 

crystals measuring 2£ inches 

across. Crystals of opaque, 

dull-red garnet half an inch 

to 2 inches in diameter are 

scattered through the pegmatite, and a few small pink 

garnets were seen in one specimen on the dump. A few yellowish 

green to pale aquamarine-green and mostly opaque crystals of beryl 

were seen in the rock. Little could be learned of the quality of the 

gem material mined, but probably neither the mica nor the beryl 

was found satisfactory in grade or quantity.

PLAYTER MICA AND BERYL MINE.

A deposit was operated for mica and gem beryl several years ago 

in the town of Springfield by Franklin Playter, of Boston. It is 

on one of the higher summits of Springfield Mountain (Melvin Hill 

of Hitchcock's Atlas), 3 miles S. 40° 'W. of Grafton, at an elevation 

of 2,100 feet above sea level. The workings consist of four open cuts 

along a small ridge. Three of the cuts are in a line extending about 

150 feet N. 55° E. on the northwest side of the ridge, and the fourth

Approximate scale » 

o 25 50 75 100 Feet

FIGI;RE 42. Plan of prospect of Columbia Gem 

Mining Co., on Springfield Mountain, Sullivan 

County,. N. H.
154 MICA DEPOSITS OF THE UNITED STATES.

is about 100 feet southeast, on the opposite side of the small ridge. 

Two of the open cuts are about 25 feet across and are connected by 

 U passage 6 feet wide. The openings range in depth from 8 to 25 

.feet.

The country rock is muscovite-biotite gneiss, which has a general 

northeast strike and a vertical to high southeast dip. The pegmatite cuts the gneiss irregularly, but its greatest length corresponds 

approximately with the schistosity of the gneiss. The deposit pinches 

and swells and thus cuts the schistosity of the inclosing rock in one 

place and is conformable with it in another. In the two connected 

open cuts the body of pegmatite is more than 20 feet wide but pinches 

down to 6 feet at the surface in the passage between the two cuts and 

widens to 10 feet at a depth of about 10 feet below the surface. 

At some places where the pegmatite pinches down in this passage it 

cuts across the bedding of the gneiss; and at others the gneiss bends 

around its bulging shape. Plate XIII, A (p. 108), shows the pinch of 

mica gneiss between the two connected open cuts. The bulging pegmatite underlies the gneiss on both sides of the passage between the 

cuts.

The texture of the " vein" rock is variable but is chiefly rather 

coarse. The quartz occurs generally in large segregations of coarse 

smoky to gray grains, but in places it occurs in translucent to nearly 

clear masses several inches across. The rock contains two varieties 

of feldspar, gray orthoclase or microcline in crystals as much as 2 

feet across, and masses of albite 3 to 4 inches across. Crystals 

of black tourmaline are plentiful, and some are of good crystal form 

Biotite occurs in large quantity, and some is intergrown with the 

muscovite. The muscovite is of good quality, splits well, and has 

a clear rum color. Some crystals seen around the workings would 

yield perfect plates measuring 2-| by 3 inches and 2 by 4 inches. 

Beryl occurs rather plentifully, and most of it is opaque, but some 

is clear and has fairly good color. The quantity and quality of beryl 

obtained from the mine can not be determined, but the dumps and 

the pegmatite contained well-formed opaque to translucent pale yellowish-green and bluish-green crystals as much as 2 inches thick, and 

a few crystals with transparent parts showing the same colors that 

Would cut into small gems. The material seems to indicate that 

larger clear beryl may still be found.

JOE HILL MINE.

The Joe Hill mine is 1-| miles N. 55° E. of Springfield, near the 

roadside. It was worked about 30 years ago by a man named Randall, but since that time it has been idle, and when examined in October, 1914, was badly overgrown. It was opened by a tunnel 40 feet
NEW HAMPSHIEE. 155

long driven N. 70° E. into a steep hillside. The country rock is 

fibrolite-mica gneiss, which strikes N. 5° E. and dips 60° E. The 

pegmatite cuts the gneiss with a strike of N. TO 0 E. and a southerly 

dip. The pegmatite is medium to coarse in texture, and contains 

feldspar crystals as large as 1 foot thick and quartz segregations 

1 foot to 2 feet thick. The mica seen in the rock was in small crystals, 

but was of good quality and had a clear light rum color. Sheets of 

waste mica that had been thrown on the dump measured more than 6 

inches across.

MUHPHY PROSPECTS.

Two prospects for mica and beryl were opened in 1914 by Charles 

Murphy, of Wilmot, on the old Underhill place, about If miles east 

by north of Springfield. The deposits are in the hilly country south 

of Springfield Mountain, at elevations of 1,800 and 1,900 feet, respectively, above sea level. They are about a quarter of a mile north of 

the Globe mine. The upper one is in a ridge sloping south. The 

work consists of an open cut about 20 feet square and 12 feet deep in 

a large outcrop of pegmatite. Much of the rock exposed in the working is graphic granite of both coarse and fine grain. In places there 

are small segregations of quartz and orthoclase crystals 1 foot or less 

in thickness. About 4 tons of small mica crystals was taken from this 

opening. This mica is of good quality and clear light rum color, 

but most of it is only large enough for punching into disks and washers. Among the associated minerals are biotite, black tourmaline, 

triphyllite in masses as much as 8 inches thick, opaque crystals of red 

garnet 2 inches in maximum diameter, crystals of beryl, a little 

llolingite or arsenopyrite, and apatite. The crystals of beryl range in 

diameter from one-sixteenth of an inch to 1^ inches. They are 

simple hexagonal crystals and occur singly, in parallel growths, and 

in radial groups. Most of them are opaque or translucent and palegreenish aquamarine in color.

The lower prospect is nearly a quarter of a mile south of the 

upper one, in a gap. A small glacial gouge cuts through the gap 

in a southeasterly direction, and the prospect consists of two openings, one on each side of this gouge and about 150 feet apart. 

A few openings have been made on the east side of the gouge 

in a face of pegmatite several feet high. The footwall contact 

 of this pegmatite strikes N. 20° W. and dips 45° NE. and the 

rock crops out for about 100 yards in this direction. The country 

rock is biotite gneiss, in which fibrolite was seen between this prospect and the upper one a quarter of a mile north. The pegmatite 

exposed in this ledge contains coarse crystals of orthoclase, some 

graphic granite, segregations of smoky quartz, hydrated biotite in 

large thin crystals, and crystals of muscovite mica as much as 8 

inches in diameter. Crystals of beryl are said to have been found.
156 MICA DEPOSITS OF THE UNITED STATES.

On the west side of the gouge pegmatite has been exposed by stripping over an area about 30 feet square. It contains coarse crystals 

of orthoclase, large segregations of quartz, graphic granite, and good 

sound crystals of mica as large as 8 inches across and 2 inches thick, 

The mica has a clear light rum color. A little biotite and a few 

opaque red garnets were observed.

Another prospect had been opened about 200 yards north of the 

upper prospect in a prominent mass of pegmatite striking N. 25° E.. 

This pegmatite contained much graphic granite, large crystals of 

orthoclase, some plagioclase feldspar, segregations of quartz about 

a foot thick, black tourmaline, greenish apatite, biotite, and small 

crystals of clear rum-colored muscovite mica. The results of the 

prospecting had not been very satisfactory.

GLOBE MINE.

The Globe mine is If miles N. 80° E. of Springfield, on a rather 

flat-topped hill about 1,875 feet above sea level. The mine was 

opened more than 40 years ago but had been idle for many years before it was examined, in October, 1914. The principal work done 

consists of an irregular open cut more than 100 feet long, 20 to 50 

feet wide, and 10 to 25 feet deep. The quarry is in a mass of pegmatite more than 150 feet wide. The work progressed from southeast to northwest, part of the waste and muck being carried back and 

thrown on the older work. Large masses of quartz were encountered in the workings, and one of these masses was left along the 

northwest face of the quarry. The mica is reported to have occurred 

in large deposits or pockets at different places in the pegmatite. 

Some of the mica that was thrown on the dumps could now be used. 

The mine yielded good, clear rum-colored mica. Black tourmaline 

is abundant, and it is reported that the first prospecting done here 

was for coal, for which the tourmaline was mistaken.

Rock was removed to the dumps by a car on a track and the same 

track led around to shops about 100 yards south of the mine. About 

4 tons of mica suitable for cutting into small sheets and punching 

had been left in the shop.

Some other prospects were opened on the same property about 200 

yards north of the main quarry, but these prospects are thickly overgrown with vegetation and little could be seen at them.

STRAFFORD COUNTY. 

FOSS MINE.

A mica deposit was worked during 1913 on the farm of H. R. Foss, 

about a mile northwest of Center Strafford, Strafford County, N. H., 

bv James Davis, under contract with the Keerie Mica Products Co.
NEW HAMPSHIRE. 157

BENCH 

LAND

The mine is on the southeast side of a benchlike projection or platform on the southeast slope of the Blue Hills Range, at an elevation 

of about 700 feet above sea level. The working consisted of an irregular-shaped open cut about 100 feet long, 10 to 30 feet wideband 

10 to 40 feet deep to water, and from 30 to 40 feet of water was reported to be in the bottom at two places. The open cut extended N. 

25° W. into the hillside, reaching nearly to the top of the bench land. 

In the lower end of the open cut a pillar of barren rock was left. 

The workings are shown in figure 43. Two dumps were made, and 

one of them was rather large. Power drills were used and the rook 

was removed by a derrick and a mine car. The mica was shipped in 

the rough to Keene, the nearest railroad shipping point being Center Barnstead, about 9 

miles to the northwest.

The country rock exposed 

in the Blue Hills Range is 

chiefly coarse mica schist and 

gneiss, highly crumpled in 

places and inclosing beds of 

pegmatite. Because of drift 

material on the hillside good 

outcrops are lacking around 

the mine. The workings expose granite, which grades into 

pegmatite at some places and 

is cut sharply by pegmatite at 

others. The granite and the 

associated pegmatite have been 

exposed for a thickness of Approximate scale 

o 25 .50 Feet

FIGURD 43.- Plan of Foss mica mine, Strafford 

County, N. H.

about 40 feet from northeast

to southwest but extend N.

25° W. for the full length of

the workings. A slight banding of the granite in a northeasterly

direction was noted, but the pegmatite cuts across this band.

Two pegmatite "veins" were opened, one striking N. 45° W. and 

dipping 70° NE. and the other striking N. 20° W. and dipping 70° 

NE. Their position is indicated by the deep stopes filled with water 

shown in figure 43. These " veins " pinched down small where development was stopped and apparently did not connect, but they consisted of streaks or shoots of pegmatite as much as 10 feet thick, 

which in places were rich in crystals of mica. Where work was 

stopped the mica-bearing veins were less than 18 inches thick. At 

one place a mass of solid mica 5 feet thick, composed of scales half 

an inch to 2 inches in diameter with little intermixed feldspar and 

quartz, was left in the side of the opening. The mica " veins " were
158 MICA DEPOSITS OF THE UNITED STATES.

reported to have been very rich where worked out and to have 

yielded some large crystals. .

The quartz of the pegmatite occurs both in scattered grains and 

in irregular-shaped masses, the largest 3 feet thick. It has a gray 

to smoky color and is opaque. The feldspar occurs in large crystal 

masses and in graphic intergrowths with quartz. Among the associated minerals were black tourmaline, which is abundant both in 

the granite and in some of the graphic granite; dark red and opaque 

garnets; beryl crystals as much as 6 inches in diameter, some of 

which had small, clear, pale aquamarine-colored parts; much opaque 

greenish apatite; and numerous grains or particles of arsenopyrite 

or llolingite.

The mica crystals vary in quality, some having the A structure 

strongly developed but yielding good flat sheets between the A lines. 

The mica has a greenish-brown cast and some is a little specked. A 

specimen obtained from one of the large crystals seen in the office 

of the Keene Mica Products Co. measured 16 by 26 inches. It would 

have yielded perfect sheets 8 by 16 inches and smaller perfect plates.

NEW JEBSEY.

An attempt -was made to mine mica near Bloomingdale,56 Passaic 

County, N. J., in the Blue Ridge Mountains.

NEW MEXICO. 

GENERAL FEATURES.

Mica deposits occur in Rio Arriba County west and southwest of 

Petaca and in the Glorieta Mountains, in San Miguel County, N. 

Mex. Other prospects are said to occur in the belt of crystalline 

rocks that extend northward from San Miguel County into Taos 

County. The mines of both regions were opened in the early days 

of mica mining, and the output was reported for the yea;rs 188)2, 

1883. and 1884.57 The deposits of Rio Arriba County have been the 

most actively developed.

MORA COUNTY.

Mica deposits are reported to have been prospected in Mora 

County 58 near the town of Mora, about 30 miles north of Las Vegas. 

Several deposits are claimed to have been found, two of which were 

thought to be rich enough to develop. The mica-bearing pegmatites

«*

59 Colles, G. W., Mica and the mica industry, p. 45, Franklin Institute, Philadelphia, 

Pa., 1906.

67 U. S. Geol. Survey Mineral Resources, 1882-1884.

53 The Mora mica deposits of New Mexico: Min. and Eng. World, May 4, 1912.
NEW MEXICO. 159

 occur in lenses in mica schist. Some of the deposits yield a black 

to brown specked1 mica and others yield clear mica. Most of the 

prospects also contain quantities of A, wedge, and tangle-sheet mica, 

but these varieties can be separated from the sheet material.

RIO ARRIBA COUNTY.

The mica deposits described below are only a few of a large number 

in Eio Arriba County, N. Mex. Many of these deposits were mentioned in a report by Holmes,59 who briefly described some of them. 

Notes for the accompanying descriptions were obtained during a 

very brief visit in June, 1911, at a time when none of the deposits 

were being worked. Through the kindness of Mr. Moritz Leichtle, 

of Petaca, N. Mex., the few examinations made were possible.

Rio Arriba County lies west of the central part of northern New 

Mexico. The eastern part of the county, in which the mica region is 

situated, is composed of broken mountain country that merges into 

partly dissected table-land. The mountains are a continuation of the 

San Juan Mountains of Colorado. The mica deposits lie at elevations 

ranging from 6,500 to more than 8,000 feet, chiefly in the mountain 

country. The region is drained by the tributaries of Caliente Elver, 

some of which are dry during part of the year. The region is a semidesert at the lower elevations but is better watered and is forested 

with pine in the higher parts. The mica deposits outcrop in two or 

more groups on a northerly line and are from 8 to 15 miles west of the 

Denver & Rio Grande Western narrow-gage tracks between Santa 

Fe, N. Mex., and Alamosa, Colo. The railroad stations that would 

serve as shipping points for the mica deposits are Servilleta and 

Barranca. Petaca, a small settlement, chiefly of Mexicans, near the 

larger group of deposits, is about 9 miles by road southwest of 

.Servilleta.

The mica mines examined were the Cribben or Cribbenville mine, 

about 2 miles southwest of Petaca; the American, about three-fourths 

of a mile S. 75° W. of Petaca; the Globe, about 5 miles south-southwest of Petaca and 12 miles west by north of Barranca; and the Antonio Joseph, 2 miles north of Ojo Caliente and 14 miles southwest of 

Barranca. All the mines but that near Ojo Caliente are within the 

area of the Jemez National Forest. The elevations at several points 

in the mica region, determined by barometer, are: Petaca, 7,500 feet 

above sea level; camp at Cribbenville mine, 7,800 feet, highest working, 8,000 feet; American mine, 7,750 feet; Globe mine, 7,650 feet; 

Joseph mine, 6,"900 feet; Ojo Caliente, 6,500 feet.

M Holmes, J. A., Mica deposits in the United States: Twentieth Ann. Kept. U. S. Geol. 

Survey, pt. 6, continued, pp. 706-707, 1899.
160 MICA DEPOSITS OF THE UNITED STATES.

'. . ' The mica deposits of New Mexico yield some sheet mica of fairly 

good quality and merchantable size. A large proportion of the output is scrap mica, suitable only for punching into disks or cutting 

into small sheets and grinding. At some of the mines the principal 

value lies in this scrap mica. With several of the better mines in 

active operation, New Mexico would occupy a prominent place among 

the mica-producing States. By establishing cutting or trimming 

plants and grinding mills, either in the mica region or at convenient 

points on the railroad, the mining industry would be stimulated, and 

advantage could be taken of the low-priced labor offered in that 

region. Much of the trimming and splitting of mica could probably 

be done by Mexican girls and women.

The description of the Cribbenville mine by Holmes is quoted 

below :

At the Cribben mine, the best known of them all, a considerable amount of 

work was done between 1884 and 1889, and on a smaller scale since that time. 

Openings were made on the property at several different locations (1) the I 

Excell tunnel, 300 feet long; (2) San Carlos tunnel, 40 feet long, where there 

are also stopes and drifts under the crest of the hill; (3) an open cut 100 feet 

long and a tunnel 40 feet long, near the San Carlos; (4) El Capitan tunnel, 

shaft, and open cut, some 1,000 or 1,200 feet northwest of Nos. 2 and 3; 

(5) Columbia tunnel, 40 feet long, with an open cut of 40 feet, in a dike 50 

feet thick, located some 200 or 300 yards east of the San Carlos; (6) the 

Rafugea tunnel, 20 feet long, and open cut, 30 feet long, located some 200 feet 

east of the last. The larger part of the work at the Cribben mine was done and 

most of the mica was obtained from the San Carlos and El Capitan openings, 

and it is in these also that there is the greatest promise of successful future 

operations. The mica from these openings is all of fairly good quality, generally 

free from specks, though in places badly ruled.

The several workings described by Holmes are not now readily 

recognized, as many of them have fallen in badly. The I Excell 

tunnel is blocked by a cave-in. The San Carlos workings are still 

open, in part at least, and mica can be obtained by continuing the 

stopes. The El Capitan workings are nearly all closed. Mr. 

Leichtle stated that the rich deposit of mica encountered in these 

workings was mined out. A quantity of mica that would yield scrap 

and small sheet remained around the workings.

During the last few years work has been concentrated on a deposit 

in a hill about 100 yards southwest of the camp and about 100 feet 

higher. A tunnel has been started in the hillside toward the " vein 'r 

and a shaft 25 feet deep and 12 feet across sunk near the summit of 

the hill. Massive coarse pegmatite containing crystals of feldspar 

2 to 3 feet across was encountered. Most of the mica appears to 

come from a streak about 8 feet across, with a north strike and west 

dip. The mica is more plentiful along the sides of this streak,, 

especially in shoots that pitch to the south. Rough crystals of mica
NEW MEXICO. 161

12 inches across were seen in the shoots and larger ones are reported 

to have been found. The mica is of fair quality, and good sheets 

can be cut from many of the crystals. The thick sheets have a 

greenish color.

The mine is now owned by the New Mexico Mutual Mining Co., 

which has an office in Milwaukee, Wis. Mr. Leichtle, who owns an 

interest in the mine, is in charge. Little more than assessment work 

lias been done for several years, and only small shipments of sheet 

mica have been made during this time. Two or three hundred tons 

of scrap mica have accumulated on the dumps and in the storehouses 

Small sheet mica could be cut from some of the scrap.

Holmes 59 mentions also other mines:

Several other claims have been prospected recently near the Cribben, notably 

the Old Judge claim, probably one-half mile to the north.

The Buckshot and Mica Producer claims, some 3 miles south of the Cribben, 

and the Petaca, Coyote, The Gulch, Bachelder No. 1, Bachelder No. 2, Summit, 

Keystone, Mica1 King, Fleming, Bobtail, and Young America, extending north 

 of the Cribben for some 4 or 5 miles, have been opened up for mica to a small 

'but varying extent and some of them are promising prospects. All yield mica 

of good quality, except that in many places it is badly ruled. The Old Black 

Horse (Sandoval or Kentucky) mine, some 3 or 4 miles northwest of the Cribben and on the slope of the canyon, is, next to the Cribben, the best-known and 

most extensively worked mine in the district, and it may be expected to yield 

in the future considerable quantities of good mica. The Highland mine, 011 

top of a hill above the Sandoval, and the California, a short distance to the east 

of the Highland, have both yielded considerable quantities of mica of good 

quality and can be counted on for further developments in this direction.

Whether the names given include any of the deposits described 

below was not ascertained. It is possible that the names of some of 

the claims were changed when the claims changed hands.

The American Mica mine, formerly owned by the American Mica 

Mining Co., is now reported to have become the property of Mr. 

Leichtle. The mine is on the brow of a hill facing east. It was first 

opened by irregular stoping from the surface to a depth of 25 feet 

and for 40 feet along the vein. Later a tunnel about 200 feet long 

and 40 feet lower than the outcrop was run into the hillside to the 

south of the workings and an air shaft raised to the stopes.

The country rock at the mine is fine-grained gneiss, apparently 

coarser grained near the pegmatite. The pegmatite as exposed in 

the workings has a north strike and a dip of 20° W. The tunnel 

cuts through more than 30 feet of pegmatite, which, allowance being 

made for dip, would give a thickness of more than 10 feet. In texture the pegmatite ranges from moderately coarse rock to some that 

is very coarse, containing feldspar crystals as much as 2 feet thick. 

In the tunnel the mica was more plentiful near the footwall of the 

pegmatite, but some occurs in the interior of the mass. One crystal
162 MICA DEPOSITS OF THE UNITED STATES.

measured 15 inches in diameter. The crystals are irregularly distributed in the vein zone but are fairly numerous. Some crystals 

occur in pockets or bunches and others in streaks in the pegmatite. 

The greater part of the mica from the upper workings is suitable 

for grinding only. It is nearly all small and.some of it occurs in 

mashed lenticular pieces as much as 3 inches across. This mica has 

been partly hydrated and has a soapy feel. It occurs in an irregular 

vein, 3 to 6 feet thick, in the pegmatite. It can be obtained easily in 

large quantities and some of it has been shipped to Denver for 

grinding.

The Globe mica mine has be«n opened by three shafts 35, 30. 

and 25 feet deep from which drifts have been run along the vein. 

The 30-foot shaft is about 200 feet S. 75° E. of the 35-foot shaft and 

the 25-foot shaft is about 50 feet farther away in the same direction. 

The 35-foot shaft has been equipped with a hoist, an air drill, and 

two 25-horsepower gasoline engines. From the bottom of the shaft 

a drift was run 12 feet east and another 30 feet west. At the end 

of the west drift a crosscut tunnel has been carried 16 feet south. 

The drifts are 6 to 8 feet wide and about 15 feet high, so that they 

might be called small stopes.

The country rock is quartz-muscovite schist, which strikes northwest and dips about 25° SW. The schist contains minor folds and 

crumplings that are visible in the mine workings as well as larger 

similar regional structural features. The pegmatite cuts the schist 

with a strike of N. 75° W. and a vertical or high north dip. The 

full thickness of the pegmatite is not exposed but is at least 30 feet 

near the main workings. From the 35-foot shaft an irregular streak 

of mica, from 3 to 8 feet thick, was followed in the drifts. This 

streak lies near the north wall of the pegmatite and has an irregular 

dip of 85° N. The quartz-muscovite schist wall rock is exposed at 

some places in the drifts. The crosscut tunnel from the end of the 

west drift follows a branch streak of mica. In parts of the main 

mica streak crystals of mica are plentiful and form nearly solid 

masses 2 or 3 feet across. Blocks of mica nearly 2 feet in diameter 

were seen in the vein, but most of the mica is badly ruled and broken, 

so that only a small proportion of it could be cut into sheets. The 

feldspar occurs in large masses and crystals and consists of both pink 

microcline and white albite. Some of the masses of feldspar measure 

10 feet across. The pink microcline occurs in the largest crystals. 

The streak of mica is separated from the north wall of the pegmatite 

by an irregular sheet of massive feldspar. Irregular masses and 

sheets of quartz occur in massive feldspar on the south side of the 

streak of mica.

In the 30-foot and 25-foot shafts relations similar to those in the 

main workings were found. A streak of mica 2 to 4 feet thick, with a
NEW MEXICO. 163

high north dip, occurs in massive feldspar. Segregations of quartz, 

some of them 3 or 4 feet thick, lie along the south side of the streak. 

The mica is of about the same quality as that of the main workings.

A 20-foot shaft has been sunk on a mica vein a quarter of a mile 

north of the Globe, on the Peacock claim. The name chosen for this 

claim is an allusion to the iridescent tarnish on seams of limonite 

found in the workings. A streak of mica 1| to 3 feet thick was exposed in the shaft. Nearly all the mica is small, and some of the 

crystals are bunched together in almost solid masses.

Two prospects for mica have been opened by Antonio Joseph in 

the foothills of the mountains west of Caliente River. One of them 

is in the walls of a gulch about 1£ miles north of Ojo Caliente and 

half a mile' west of the river. It has been opened on each side of 

the gulch. The other prospect, which is the more promising 

of the two, is about half a mile northwest of this one, in the east 

end of a ridge between two draws tributary to the same gulch. Here 

several openings have been made in the hillside on the spur of the 

ridge and on the south side. The larger opening is a cut 15 feet 

long, from which an 18-foot tunnel has been carried and there is a 

12-foot shaft at the end of the tunnel.

The country rock of the region consists of mica, cyanite, quartz, 

garnet, and hornblende schist and gneiss, granite, pegmatite, and 

basalt. The schist and gneiss have been much folded, and the axes 

of the larger folds are crossed by smaller flexures. The general 

strike near the mica deposits is N. 45°-60° E., with a vertical to west 

dip, but large variations from this attitude occur. Pegmatite is common in the gneiss and schist of this region.

At the best prospect a mass of pegmatite at least 100 feet wide 

crops out across the end of the ridge, with a probable northeast 

strike. This pegmatite shows the usual variations in composition 

and texture, part of it containing feldspar and quartz, with or without mica, in granular mixtures and part containing segregations of 

these minerals. The feldspar is gray and pink to red and is chiefly 

of the potassium variety. The mica occurs in pockets and streaks as 

much as 20 feet thick in the pegmatite. The streaks have an approximate northeast strike and are richer in mica in some parts than 

in others. A large quantity of mica is exposed in the main working. 

Most of it is in small crystals, but some crystals 12 to 18 inches 

across and 4 to 12 inches thick were seen. Nearly all were so badly 

crushed and cut by " ruling " and irregular fractures that only small 

perfect sheets, not more than 2 or 3 inches across, could be obtained 

from them. The mica from this deposit would be valuable chiefly 

for grinding and for small sheets. The mica is in greenish sheets 

a sixteenth of an inch or more thick, and some of it contains specks
164 MICA DEPOSITS OF THE UNITED STATES.

of magnetite. From 50 to 100 tons of scrap and small sheet mica 

have accumulated on the dumps.

At the other locality a mass of pegmatite 8 to 15 feet thick crops 

out on each side of the gulch, with a strike of N. 40° E. and a nearly 

vertical dip. This pegmatite contains streaks of mica gneiss from 

1 inch to 2 feet thick. The crystals of mica are more plentiful near 

these inclusions. Only small crystals of mica, 1 to 4 inches across, 

were seen, and many of these were crushed and ruled into small 

pieces.

Deposits of mica were prospected in Rio Arriba County in 1913 

and 1914 by W. J. Nelson, formerly of St. Joseph, Mo., but later of 

Petaca, N. Mex. The deposits are 5 miles west of Petaca and northwest of the Cribbenville mine. Large deposits with rich outcrops are 

reported. A specimen sent to the Geological Survey measured about 

5^ by 9 inches. It was somewhat ruled, so that it would yield only 

smaller sheets of three or more sizes measuring up to 2| by 3 inches. 

It had a fine smooth cleavage and split in flexible sheets of extreme 

thinness. The mica is nearly clear, having only slight cloudy 

inclusions.

SAN MIGUEL COUNTY.

Mica deposits were reported in the Glorieta Mountains of San 

Miguel County in the early days of mica mining, but regular prospecting had been abandoned for many years prior to 1909, when H. S. 

Anderson opened some of the deposits and made a shipment to 

Chicago. In 1910 the claims located by Mr. Anderson were taken 

over by the Anderson Mica Mining Co., of Topeka, Kans. Difficulties were encountered during the operation of the company and a 

lease of the property to the Topeka Mica Manufacturing Co. led 

to litigation. The settlement of the dispute left Mr. Anderson in 

possession of the property, and a new company, the San Miguel Mica 

Co. was formed to work the deposits.

The claims of the San Miguel Mica Co. are in the southern part of 

the Glorieta Mountains, about 10 miles by road northeast of Ribera 

(formerly San Miguel station). A number of claims have been 

located, but only two, equipped with shafts and larger developments, 

have been opened.

The following notes on the geology of the deposits have been 

abstracted from reports of mining engineers who have examined the 

property: The country rock is highly foliated muscovite schist, 

which varies in strike from east and west in the southeastern part 

of the property to nearly north and south in the western part. The 

dip of the mica schist is mostly high, ranging from 45° to 80°.
NEW YORK. 165

The pegmatites are conformable with the foliation of the schist. 

The deposits opened for mica range from 4 to 12 or more feet thick 

and in places contain a large proportion of this mineral.

The bulk of the mica output is scrap, suitable only for grinding, 

but some sheet mica is obtained. Specimens of the sheet mica submitted to the Geological Survey show that most of it would be suitable for punching into washers or trimming into sheets 1£ by 2 

inches to 2 by 3 inches. One piece would trim into a sheet 2 by 

6 inches or into two imperfect sheets, one 3 by 3 and the other 

2 by 3 inches. The mica is specked with thin films of magnetite, 

which in places have oxidized to reddish and brownish stains of 

hematite and limonite. A large part of it, which might have been 

fit for making sheet mica, has been ruined by excessive ruling and 

crumpling, so that it is suitable only for scrap or for punching.

NEW YORK. 

GENERAL FEATURES.

Mica has been found at several places in New York State and has 

been prospected or worked on a small scale at a few places. Part 

of the output has been obtained as a by-product in quarrying feldspar, but this part is chiefly scrap mica, suitable only for grinding. 

Sheet mica is reported to have been obtained from St. Lawrence 

County.

None of the mica deposits in New York have been visited by the 

writer. E. S. Bastin 00 has visited the feldspar quarries in which 

mica has been found, and the descriptions of the deposits in Saratoga and Westchester counties are taken from his report. Feldspar is 

quarried from pegmatite in Fulton and Essex counties, but Bastin 

observed little mica in them. An early report 01 mentions the discovery of mica at Chester, in Warren County.

ST. LAWRENCE COUNTY.

A deposit of phlogopite mica was operated in St. Lawrence 

County during part of 1909 and 1910 by Henry Brewster, of Syracuse, N. Y. The mine is about 1^ miles from Oswegatchie, near the 

main highway from that place to the village of Fine, on the south 

side of Oswegatchie River. Mr. Brewster states that the work done 

during the autumn of 1909 consisted of an open cut 8 feet wide and

80 Economic geology of the feldspar deposits of the United States: U. S. Geol. Survey 

Bull. 420, pp. 57, 60, 1910.

81 Eng. and Min. Jour., vol. 36, p. 88, 1883.

111375 23 12
166 MICA DEPOSITS OF THE UNITED STATES.

20 feet deep. Mica is obtained in crystals measuring as much as 8 

inches across.

SARATOGA COUNTY. 

BATCHELLERVILLE QUARRY.

The Batchellerville mica quarry, operated by the Claspka MiningCo., of Trenton, N. J., is 2 miles north of Batchellerville, in the town 

of Edinburg, on the east side of the Day-Batchellerville road. Two 

openings have been made. The pegmatite in the main quarry is 

very coarse grained. Quartz occurs in pure masses several feet 

across and in graphic intergrowth with feldspar. Light-gray microcline feldspar, with small quantities of finely intergrown albite,, 

occurs in nearly pure masses as much as 4 feet across. The finergrained pegmatite contains crystals of mica, some of which are 16 

inches wide and 8 inches thick. Some of the crystals are tapering 

and others are sharply outlined six-sided or diamond-shaped prisms, 

but Bastin did not observe any with sufficiently good cleavage for 

use as sheet mica, all being suitable for grinding only. Other minerals of the pegmatite are biotite and beryl. The beryl occurs chiefly 

in translucent dark bluish-green crystals. Or^e observed by Bastim 

measured 8 inches in width and 30 inches in length.

WESTCHESTER COUNTY. 

KINKEL QUARRY.

The Kinkel quarry is on the east and northeast slopes of a hill 

about three-quarters of a mile southeast of Bedford. Four quarries 

have been opened, each extending from northeast to southwest probably along the strike of the pegmatite. In one of the middle openings' 

the pegmatite consists chiefly of quartz, most of which is white, but 

which here and there assumes a beautiful rose tint. In the other 

quarries most of the pegmatite consists of feldspar. Pinkish microcline, some graphically intergrown with quartz, and white albite 

are the principal varieties of feldspar. Other minerals are muscovite and biotite mica, black tourmaline, beryl, and a little magnetite,, 

garnet, and columbite.

The mica is nearly all associated with the feldspathic constituents 

of the pegmatite, but some of it lies between the large masses of 

feldspar and quartz. Many of the mica crystals lie with their cleavage perpendicular to the feldspar-quartz contact. Most of them 

are less than 5 inches in diameter and have A structure. Bastin saw 

no sheet mica and doubts whether there was sufficient scrap mica to 

pay for mining.
MICA DEPOSITS OF THE UNITED STATES. 167 

NORTH CAROLINA. 

GENERAL FEATURES.

Mica mining was an ancient industry in North Carolina. Traces 

of the old pits and trenches dug by the aborigines may still be found, 

but they were much plainer when the modern period of mica mining 

was begun, in 1867. Mention of this older mining has been made by 

W. C. Kerr,62 W. B. Phillips,63 and others. Kerr speaks of the large 

operations of the ancient mica miners and suggests that they were 

probably the work of the so-called mound builders, although no 

mounds were build in the mica regions of North Carolina. Phillips 

speaks of the prehistoric mica miners as disposing of their mica, or 

of part of it at least, to the mound builders, and states that large 

sheets were found in some of the old mounds. He also comments on 

the ability of these ancient miners to find the valuable deposits and 

to extract the mica. Their work was limited chiefly to the upper, 

decomposed parts of the pegmatite; they attempted very little hardrock mining. Only stone hammers and axes have been found .around 

the old workings, but evidence that other implements were used in 

mining has been observed. Phillips states that about 1,800 feet of 

large pits and trenches had been dug at the Silvers or Sink Hole 

mine by the aborigines. Some of these workings were 20 feet deep, 

and the debris removed from them was covered with large trees, 

showing their great age.

C. D. Smith 64 has furnished an interesting description of one of 

the ancient mica mines near Franklin, and part of his article is 

quoted below under Macon County.

Modern mica mining in North Carolina was begun in 1867 by L. E. 

Persons, of Philadelphia, previously of Vermont. Mr. Persons's 

attention was directed to Jackson County by some one in Philadelphia who had seen a crystal of mica exhibited at the State fair in 

Columbia, N. C., in 1858, by D. D. Davies, of Webster. In the 

autumn of 1867 Mr. Persons went to Jackson County and learned 

from Mr. Davies the location of favorable prospects for mica in 

Jackson and Haywood counties, which he soon opened. 05

Mica mining was begun almost as early in other counties. According to W. B. Phillips, Thomas L. Clingman opened a few prospects in Cleveland County late in 1867 but did not continue working

02 The mica mines of North Carolina : Am. Inst. Min. Eng. Trans., vol. 8, pp. 457-462, 

1880; Eng. and Min. Jour., vol. 31, pp. 211-212, 1881.

03 Mica mining in North Carolina : Eng. and Min. Jour., vol. 45, pp. 286, 306, 322, 

382, 398, 418, 436, 1888.

61 Ancient mica mine in North Carolina: Smithsonian Inst. Kept., 1876, pp. 441-443.

65 This information was furnished by Judge D. D. Davies and Mrs. John L. Richardson, daughter of L. E>. Persons, in a certified statement dated Mar. 22, 1907.
168 MICA DEPOSITS OF THE UNITED STATES.

them. In 1868 he opened the Silvers or Sink Hole mine in Mitchell 

.County, looking for silver. Fine mica was found, but none of it was 

shipped. After the prospect was abandoned a crystal of the mica 

was carried by a stock drover to Knoxville, Tenn., where J. G. Heap, 

of Heap & Clapp, dealers in stoves, recognized its value, and that 

firm went at once to Mitchell County and was soon mining several 

deposits, including those worked by the Clarissa, Deake, and Flat 

Rock mines. After Heap & Clapp had shown the value of their deposits other mines were opened. Some of the better of these were 

the Ray, Westall, Joe Gibbs, Young, and Bailey Mountain mines.

so 100 150 200 "Miles

Chiefly c/ear rum- Areas ofprincipaf Chiefly dark-co/ored 

colored mica product/on or specked mica

FIGURE 44. Map showing areas in North Carolina in which mica has been mined.

Phillips estimates that the bulk of the 400,000 pounds of mica 

mined in North Carolina from 1868 to 1882 came from the Heap & 

Clapp properties. This mica must have been worth at least $800,000, 

as most of it brought from $2 to $11 a pound.

Mica mining has continued in North Carolina since 1867. The 

bulk of the output once came from a number of large mines, but 

now much of it is obtained from numerous small mines or prospects 

which are worked more or less intermittently. In some years the 

output is made by 75 to 100 different mines and prospects.

Mica deposits occur in more than 20 counties of North Carolina, 

chiefly in the western part. (See fig. 44.) The principal mines are 

in a belt nearly 100 miles wide, bounded by the State lines on the 

south, northwest, and north. A few scattered deposits occur far-
NORTH CAROLINA. 169

ther east, in the Piedmont Plateau region near Raleigh and'near 

Warrenton, close to the border of the Coastal Plain. The main 

mica belt may be subdivided into three smaller broken belts the 

Cowee-Black Mountain belt, the Blue Ridge belt, and the Piedmont 

belt. The Cowee-Black Mountain belt lies northwest of the Blue 

Ridge Mountains and extends almost across the State, parallel to 

and near its northwestern border. It includes part of Macon, Jackson, Transylvania, Hay wood, Buncombe, Yancey, MitchelJ, Watauga, 

and Ashe counties. The Blue Ridge belt follows the Blue Ridge, 

through the State and extends several miles to the southeast, among: 

the foothills. It is less productive than the other two, but it includes 

mines in Jackson, Transylvania, McDowell, Caldwell, and Wilkes 

counties. The Piedmont belt lies in the Piedmont Plateau, southeast of the Blue Ridge. In this belt mica mines have been worked 

in Rutherford, Burke, Cleveland, Gaston, Lincoln, Catawba, and 

Stokes counties. Mica deposits of commercial value have not been 

found in unbroken succession in any of these' belts.

The quality of mica obtained varies considerably from place to 

place, though the quality of that mined in a single belt or in adjacent 

parts of the same belt is generally very similar. The mica of the 

Cowee-Black Mountain belt is clear and usually rum colored; that 

from the Blue Ridge belt has a dark smoky-brown or greenish-brown 

color and much of it is more or less specked. Most of the mica in 

the Piedmont belt, especially that mined in Cleveland, Gaston, and 

Lincoln counties, is of good quality and similar to that in the CoweeBlack Mountain belt, but in some places it is affected by geologic 

conditions, such as the presence or absence of granite near by. 

v The Cowee-Black Mountain and the Blue Ridge mica belts are in 

the heart of the Appalachian Mountains. The mica deposits in these 

belts lie at elevations between 1,500 feet and more than 6,500 feet 

above sea level. Some are high up on rugged slopes or summits, 

where the soil is thin. Others are on the gentle slopes of valleys or 

on former plateaus or terraces, under a deep cover of residual clay. 

Many of the deposits present ideal conditions for mine drainage, 

which is important, for the rainfall in the region is great and the 

ground water does not lie deep. The deposits in the Piedmont belt 

are in the low but locally steep ridges or in the few hills or mountains that stand well above the general level of the plateau. The 

plateau lies from 800 to 1,500 feet above the. sea in the mica region 

and is dissected by river and creek valleys 200 to 300 feet deep. 

The sky line seen from any prominent ridge is approximately level, 

though mountains or peaks rise above it at intervals. The problem 

of mining mica from some of the deposits in the Piedmont belt is 

difficult on account of their occurrence in hills that have slight ele-
MICA DEPOSITS OF THE UNITED STATES.

vation and gentle slope, so that the mines can not be drained naturally.

The name and location of many of the mica mines and prospects 

in North Carolina is shown on Plate XIX.

OCCURRENCE OF DEPOSITS.

The mica deposits of North Carolina have been found in highly 

metamorphic rocks, probably all of Archean age. These rocks are 

mica, garnet, kyanite, staurolite, hornblende, and granite gneisses 

and schists. Other rocks in the region, also of Archean age, are 

granite, diorite, and peridotite and the soapstone and serpentine derived from them. Younger granite, volcanic rocks, diabase, and 

sedimentary deposits occur in parts of the region. The gneisses 

and schists have been so much folded, faulted, mashed, and recrystallized that it is at some places difficult to determine whether 

the original formations were igneous or sedimentary.

Most of the mica deposits occur in two formations, mapped by 

Keith 66 as the Carolina gneiss and the Roan gneiss. The Carolina 

gneiss includes most of the gneisses and schists mentioned above 

that are not hornblendic. The Roan gneiss is composed of hornblende gneiss and hornblende schist but includes smaller beds of 

mica gneiss and mica schist. By far the most extensive formation 

in the mica region is the Carolina gneiss, which is also the oldest 

"formation in the region and is intruded by younger igneous rocks, 

such as hornblende gneiss and schist, peridotite, granite gneiss, and 

diabase. All the formations have been gashed and cut by later 

igneous rocks into irregular-shaped masses, in many places forking 

out into long tongues or occurring as long, narrow streaks in the 

intrusive rocks, or vice versa. The diabase rocks, which are probably of Triassic age, cut across the strike of the older formations 

in long, narrow dikes. The Carolina and Roan gneisses have been 

interbanded with and cut at all angles by numerous streaks of 

granitic or pegmatitic material. These streaks vary in thickness 

and locally pass into mica-bearing pegmatites. At some places this 

pegmatization is so thorough that mica gneisses become strikingly 

like granite gneisses.

MINERALS ASSOCIATED WITH PEGMATITE.

The bodies of mica-bearing pegmatite in North Carolina have 

yielded many accessory minerals, some of which are of commercial

«" Keith, Arthur, U. S. Geol. Survey Geol. Atlas, Cranberry (No. 90), Asheville (No. 

116), Mount Mitchell (No. 124), Nantahala (No. 143), Pisgah (No. 147), and Roan 

Mountain (No. 151) folios.
LIST OF MINES AND PROSPECTS

U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XIX

MAP OF WESTERN NORTH CAROLINA SHOWING LOCATION OF MICA MINES AND PROSPECTS

10.

11.

1.

2.

1.

2.

3.

4.

5.

6.

7.

8.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24. 

26.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

41.

42.

ASHE COUNTY.

.Little Phoenix^Tarkington, and Foster mines 

(.Witherspoon mines) 

Goodman mine. 

South Hardin mine. 

Harris or Duncan mineNorth Hardin mine. 

Hamilton mine. 

Walnut Knob mine.

AVER1* COUNTY. 

Pyatt and Vanes m!r 

Johnson mines. 

Pfumtree mine.

Milton English and White Rock mines. 

McCoury mines. 

Powdermif! Creek mines. 

Meadow mine.

Doublehead and Alfred orVance mines. 

Charlies Ridge mine.

BUNCOMBE COUNTY. 

New Balsam Gap mine. 

Brushy Mountain mine. 

Connalty and W. H. Burnett mines. 

Gustavino and Reese mines. 

R. M, Davidson mines.

BURKE COUNTY. 

Buzzard Roost Knob prospect. 

Burkmont prospect.

CATAWBA COUNTY. 

J. E. Burleson prospect.

CLEVELAND COUNTY. 

W= H. Thompson or Wyatt mine. 

Calvin Carpenter mine. 

Fraser-English prospect. 

M. M. Mauney mine. 

S. J. Green mine. 

Indian Town mines. 

Casar mines.

Hambrick, Ellis, and other mines. 

Sam Putnam, Tom Cabaniss, and Maynard

Washfourn mines. 

W. F. Gold mine. 

J. H. Royster mine,

GASTON COUNTY. 

Mauney Carpenter mine. 

M. M. Carpenter mines.

HAYWOOD COUNTY. 

Spruce Ridge mine. 

Shiny mine. 

Big Ridge mine. 

Shining Rock prospect. 

Middle Otci Field Knob prospect. 

Mark Reeoc mine. 

I. T, Walls prospect. 

Ethan Cook mine.

JACKSON COUNTY. 

Big Flint mine. 

Piney Mountain mine. 

Ruby City mine and SugaHoaf Mountain

prospect.

Ocher Hill mine (marked but not numbered). 

Tustin kaolin and mica mine. 

Painter mine. 

E. D. Davis prospect. 

George White prospect (marked but not

numbered). 

Adams mine. 

Bob Ashe mine. 

John Long mine. 

C. D. Bryson mine. 

Wayehutta kaolin and mica mine. 

Rock mine. 

Sheep Mountain mine, Wolf Pen Gap Trail

prospect; and Hamp Woods prospect. 

Cedar Cliff mine. 

Leon Hooper mine. 

Coward Mountain mine. 

Brown's Coward Mountain prospect. 

Abbs Creek mine. 

Frady Creek mine. 

Lewis Queen mine.

J. B. Price mine and A. L. Lovedahl prospect. 

Andy Nicholson mine. 

East Laport mine and Roda kaolin and mica

mine.

Cox & Davies mine. 

Mrs, Kelier's mine. 

Presley mine and Spence prospect. 

Gregory mine. 

Island Ford mine. 

Freeman Baird mine. 

Jim Wood mine. 

A. E. Galloway mine (marked but not

numbered) 

James Reece mine. 

Affaert Brown prospect. 

Camp Mountain mica and kaolin mine. 

Pinhook Gap mine. 

Thomas Grimshawe mine. 

D. L. Watson mine. 

J. H. Rochester mine. 

Jake Rica mine. 

Rice mica and beryl mine.

	LINCOLN COUNTY.

1. Thomas Baxter and Frank Baxter mines.

2. I. K. Wilson prospect.

3. W. A. Thompson and Joe Stamey mines.

4. M. M. Hull mine.

5. John DUIinger mines.

6. D. C. Heavner mine.

McDOWELL COUNTY.

1. Sourwood Gap prospect.

2. Prospect northwest of Woodlawn.

MACON COUNTY.

1. Burningtown or Poll Miller mine.

2. Ruth Stalcup mine.

3. Turkey's Nest and Lyle Cut mines.

4. Wayah Bald mine.

5. Roaring Fork mine.

6. Thorn Mountain mines.

7. Winding Stair mine.

8. Dobson mine.

9. I. A. Deal prospect.

 10. Smith or Baird and C. T. Blaine mines. 

11. Johnston mine. 

12 / Winecoff and Harris mines.

'( Ra by-Sweet, lotla. and N. L. Bernard mines.

13. Chalk Hill mine.

14. Jotla Bridge kaolin and mica mine.

15. Neal Bryson mine.

16. James Bryson and West mica and kaolin mines.

17. Hail and Welch mines.

18. Boyd Knob mica and kaolin mine. 

ig /BeasleyNo, 1 mine. 

3 * ( Beasiey No. 2 mine.

20. Campbell or Higdon mine.

21. Lyie Knob mine.

22. Berry and Sanders mica and kaotin prospects.

23. L. J. Bailey kaolin and mica mine.

24. Fox mine.

25. , Elmore mine.

q/> ) Kasson or Holbrook mine.

' (Quizzenberry, Ledford,and Mill Knob mine.

27. Moore or Cabe mine,

28. Corundum Hill mica mine.

29. Bascom mine.

SO. A. W. Young mine.

31. Mines along Cowee Mountains.

	MfTCHELL COUNTY.

1. Knob mine and Survey prospect.

2. W. W. Wiseman and Harris Ciay Co. mines.

3. Z, T. McChcne mines.

4. Chalk Mountain mine.

5. F. M. Toliey mine.

6. Deake, Bill Willis, and Westall mines.

7. Blalock mine.

8. Flat Rock mine.

9. Edgar Bros, kaolin and mica mine.

10. Gibbs Green mine.

11. Mines of Carolina Mineral Co.

12. Sink Hole and Randall mines.

13. Buchannan mine.

14. Hawk, Clarissa, and Cloudland mine.

	RUTHERFORD COUNTY.

1. isinglass Hill mine.

2. Cherry Mountain prospect.

3. Prospect near Union Mills.

4. Alien and J. Odom prospects.

5. Joseph Groves prospect.

6. W. T. Wilkins prospect.

7. W. H. Marviil prospect.

STOKES COUNTY. 

1. Joe Hawkins and Steeie mines.

TRANSYLVANIA COUNTY.

1. Bee Tree Fork mine.

2. Chestnut Ridge mine.

3. Taliow Face mine.

4. Reed mine.

5. W. J. Nickelson mine.

6. Morning Star mine.

7. Big Jumbo mine.

8. Little Jumbo mine.

WATAUGA COUNTY.

1. Dobbin, Clawson, and Todd mines.

2. Arney Foster mine.

3. C. C. Green prospect.

4. Locke Green mine.

5. F. A. Linney mine.

WILKES COUNTY. 

1. Joel Tripiett mine.

YADKIN COUNTY. 

1. Mauser mine.

YANCEY COUNTY.

1. Green Mountain and Letterman mines.

2. Ray mine.

3. Cattail Branch mine.

4. Gibbs mine. 

6. Poll Hill mine.

6. Hensley mine.

7. Young mine.

8. Bailey Mountain mine.

9. Aley mine.
U. S. OEOLOGICAL SURVEY DUIXETlN 740 fLATB XX

A. VIEW IN STOPE OF NOltTH IIARDIN MICA MINE, ASHE COUNTY, N. C 

Loose masses of mica crystals between stulls.

B. MICA-TRIMMING SHOP OF WALNUT KNOB MICA MINK, ASHE

COUNTY, N. C.
U. S. GKOLOcri'AL SURVEY 1HTLLKTTN 740 PLATE XXI

A. VIEW NOKTHWAIU) TOWARD .MEADOWS MICA MINE, AVERY COUNTY,

N. C.

B. PEGMATITE SHOWING FINK-GRAINED CONTACT NEAIl WALL, AT 

McKINNEY OR I'OWDKRMILI. CRKIOK MICA MINE, AVERY COUNTY, N. C.
NORTH CAROLINA. 171

value, and some bodies that do not contain valuable mica have 

yielded other minerals that are of more or less value. Dr. Joseph 

Hyde Pratt, State geologist of North Carolina, has kindly prepared 

the following complete list of minerals associated with pegmatite 

in that State. Asterisks are placed before the names of minerals 

that have been found in quantity and of quality sufficient to give 

them commercial value:

Minerals found in the pegmatites of North Carolina.

Actinolite.

*Albite (feldspar). 

Allanite.

*AImandite (garnet). 

Andraelite (garnet). 

Apatite.

*Auerlite. 

Autunite.

*Beryl (emerald, yellow, blue, and 

aquamarine).

*Biotite (mica). 

Brookite.

*Cassiterite.

Chabazite.

Columbite. 

^Corundum.

Enstatite.

Epidote.

Eucryptite.

*Feldspars (albite, oligoclase, orthoclase, microcline). 

Fergusonite. 

Fluorite. 

Gadolinite. 

Garnet (almandite, andradite, pyrope, spessartite). 

Graphite.

*Gummite (uranium ore). 

Hatchettolite. 

Hematite.

Hiddenite (variety of spodumene). 

Hyalite (variety of opal). 

Ilrnenite (menacconite, titanic iron), 

lolite.

*Kaolin. 

Kyanite. 

Limonite.

Magnetite. 

Menacconite (ilmenite).

*Mica (biotite, muscovite). 

Microcline (feldspar). 

Microlite. 

Molybdenite.

*Monazite. 

Nivenite.

*Oligoclase (feldspar).

Phosphuranytile (uranium mineral).

Purpurite.

Pyrite.

Pyrope (garnet).

Pyrophyllite.

Pyrrhotite.

"'Quartz (massive, crystallized, and 

smoky).

Rogersite.

Rutile. 

eSamarskite.

Spessartite (garnet).

Sphene (titanite).

Spodumene (hiddenite).

Tantalite.

Thulite (variety of zoisite).

Titanite (sphene).

Topaz.

Tourmaline (black).

*tJraninite (pitchblende).

*Uraniutu minerals (autunite, gummite, phosphuranytile, uraninite, 

uranotil).

Uranotil.

Xenotime.

Yttrialite.

*Zircon. 

Zoisite (variety of thulite).

PRODUCTION.

For several years North Carolina has produced more mica than any 

other State, and the value of its product has ranged from one-half 

to two-thirds of that of the total output of the United States every
172 MICA DEPOSITS OF THE UNITED STATES.

year since 1900 except 1908. The production since 1906 is given in 

the following table:

Mica produced in North Carolina, 1906^-1915.

Year.

1906................................................

1907................................................

1908.................................................

1909. ...............................................

1910. ...............................................

1911................................................

1912. ...............................................

1913................................................

1914................................................

1915................................................

Sheet.

Pounds.

800,440 

645,221 

599,234 

1,296,274 

455,020 

454,653 

489,599 

803, 462 

274, 121 

281,074

Value.

$205,7.56 

209,956 

114,540 

122.246 

193,223 

187, 501 

219,874 

236,674 

171,370 

266,650

Scrap.

Short 

tons.

1.129 

1,371 

1,308 

2,607 

3,074 

2,347 

2,492 

2,729 

1,789 

2,840

Value.

$11,940 

15,250 

13,330 

26,178 

37,237 

29,798 

36,675 

37,239 

23,900 

33,943

Total 

value.

$217,696 

225,206 

127,870 

148,424 

230,460 

217,299 

256,549 

267,913 

195.270 

315,017

ASHE COUNTY. 

HISTORY OF MINING.

A number of mines in Ashe County have produced good mica in 

the past and some are still producing it. Considered geographically 

the mines in the county may be divided into three groups those 

northeast of Jefferson, those west of Beaver Creek, and those northwest of Elk Crossroads. Among those northwest of Jefferson are 

the Little Phoenix, the Tarkington, and the Foster mines. The 

mines west of Beaver Creek that have been operated on a large 

scale are the Harris, the Hamilton, and the two Hardin mines. The 

largest producer in the region northwest of Elk Crossroads is the 

Walnut Knob mine.

The Little Phoenix and the Walnut Knob mines are said to have 

been worked in prehistoric times by the aborigines, and the remains 

of the old workings are still pointed out to the visitor. Mica was 

first mined in Ashe County by white people probably at the Tarkington mines, between 1870 and 1875, and most of the mica mines in 

the county were opened between 1880 and 1890. All the mines in 

the county have been idle during certain periods. The Goodman, 

the Hamilton, and the two Hardin mines were operated by the Blue 

Ridge Mica Co. between 1900 and 1902. The mines in Ashe County 

were then idle until 1906, when Theodore Westall reopened the 

Walnut Knob mine and worked the dumps at the Harris, North 

Hardin, and Hamilton mines for small-sheet mica. In 1907 the 

Hardin and Hamilton mines were reopened by the Johnson-Hardin Co.

LITTLE PHOENIX MINE.

The Little Phoenix mine, now owned by W. H. Witherspoon, is 2£ 

miles N. 60° E. of Jefferson, on the east side of Little Phoenix
NORTH CAROLINA. 173

Mountain. The mine is on a rather steep hillside and has good 

facilities for opening and draining. The mass of pegmatite worked 

was mined by the aborigines along its outcrop, which follows the 

outcrop of a ledge of massive white quartz up the slope of the hill. 

The remains of the aboriginal workings can still be seen. The mine 

has not been operated for twenty years, and the formations are 

therefore poorly exposed. The workings consisted of three shafts 

and a few test pits, sunk a little south of the outcrop. These shafts 

are said to have been connected at a depth of TO feet by a tunnel.

The pegmatite strikes about N. 75° E. and dips about 60° S. It 

lies in mica gneiss that includes bands of hornblende gneiss. The 

ledge of massive quartz along which the aborigines made their 

openings probably represents the footwall of the pegmatite, and the 

part of the mass that is richest in mica lies next to this wall. The 

mica is of good quality. Garnet and beryl were found in the mine, 

most of the beryl in the massive quartz. Crystals of beryl as large 

as a man's arm are reported to have been found.

TARKINGTON MINE.

The Tarkington mine, now owned by W. H. Witherspoon, is 

about 300 yards southwest of the Little Phoenix mine, about 2 miles 

N. 60° E. of Jefferson. The workings are old and have fallen in 

badly. They consist of several cuts and a shaft in a distance of 

150 feet and a crosscut trench about 100 yards farther southwest. 

The mine is on a hillside and could be opened by a crosscut and 

drainage tunnel. The pegmatite appears to be conformable with 

the inclosing hornblende gneiss, the country rock. Mica of good 

quality and crystals of beryl are said to have been found.

FOSTER MINE.

The Foster mine is about half a mile southeast of the Little 

Phoenix mine, or 2£ miles N. 65° E. of Jefferson. It has been 

opened by a crosscut about 20 feet wide. A mass of pegmatite 

15 feet thick is exposed between walls of hornblende gneiss. The 

gneiss strikes N. 55° E. and dips 50° SE. Pegmatite is plentiful 

in the country rock near this mine.

HAMILTON MINE.

The Hamilton mine is on the west slope of a mountain 2 mileis 

northwest of Beaver Creek. It was reopened by the Johnson-Hardin 

Co. in 1907, since the accompanying notes were taken. The deposit 

was opened by two tunnels run into the hillside along the vein. In 

the upper and earlier one a shaft or winze was sunk 35. feet from 

a point about 20 feet in from the mouth of the tunnel. From the 

bottom of this shaft a curved tunnel was cut on vein material. The
174 MICA DEPOSITS OF THE UNITED STATES.

second tunnel was run at a lower level for a distance of 75 feet 

about south and did not connect with the upper one. This tunnel 

did not follow the pegmatite closely, but seemed to cut across its 

strike at a small angle. The strike of the pegmatite appeared to

be about N. 10° E. and the 

pit dip nearly vertical or to the 

east. The pegmatite is composed of feldspar and quartz 

in fairly coarse aggregates, 

with both muscovite and biotite in good-sized sheets. The 

muscovite mica is of excellent 

grade and has a clear light to 

dark rum color. The larger 

blocks of mica yielded sheets 

6 by 8 or 8 by 10 inches, but 

the principal output was 

in smaller sizes. The biotite occurs in sheets of nearly 

equal size, and some of it 

is intimately intergrown 

with muscovite, the two 

having the same cleavage 

EXPLANATION plane. 75 -80°

Tunnels and stopes

Open cut

NORTH HARDIN MINE.

The North Hardin mine is 

in a ridge about 1| miles west 

of Beaver Creek. It has been 

worked on a large scale and 

more systematically than 

most other mica mines in 

North Carolina. The mine 

was operated by two open 

cuts and other pits, three 

crosscut tunnels to the " vein," 

two shafts, and considerable 

drifting and stoping on the

FIGURE 45. Plan of North Hardin mine, Ashe vein These workings have

County, N. C. ' , . ., » ,, proved the continuity of the

pegmatite for a length of more than 100 yards and have shown 

that it ranges in thickness from 3 to 8 feet. The country rock 

of the region is hornblende gneiss, but the mica deposit is in a 

smaller belt of biotite (probably granite) gneiss. The strike of the
NORTH CAROLINA. 175

pegmatite is about N. 20° E. and the dip is 75°-80° E. At a place 

about 80 yards north of the main workings a shallow shaft was 

sunk in line with the " vein " on a small streak of pegmatite 18 inches 

thick, which was probably the main " vein " pinching out. Figure 

45 shows the extent of the work open for examination at the time

 of visit. A large part of the stoping and drifts had caved in and

 could not be seen. The greater part of the vein above the tunnels 

:shown in the figure had been removed, however, and future work 

should be directed to vein matter between old workings and to lower

 depths, easily attained with facilities for draining. Tunnel No. 3 

is probably 50 feet higher than No. 1. The mine produced a large 

quantity of small block mica, yielding sheets 1 inch by 2 inches and 

3 by 4 inches. A number of larger blocks, yielding sheets 6 by 

8 and more inches square, were found with the smaller material. 

Many small blocks of mica and one crystal more than 10 inches 

thick and a foot wide were seen in the " vein," embedded in feldspar. 

A view in one of the stopes (2) is shown in Plate XX, A. A small 

mica crystal about 6 inches thick, of unusual perfection, has been 

split into several pieces and left near the place where it was found 

along the footwall. The mica has a beautiful clear rum color and 

is of the best grade. Most of the blocks yield sheets of perfect quality.

SOUTH HARDIN HIKE.

The South Hardin mine is near the top of a small mountain or 

hill about 1£ miles southwest of Beaver Creek. The first openings 

made here were small pits, trenches, and a tunnel along the " vein." 

The surface workings were at the summit of the hill, and the 

tunnel was on the outcrop about 40 feet lower down to the northeast. 

The mine was later operated by a 30-foot shaft near the top of the 

hill and an open cut on the " vein," about 75 feet long and 10 to 20 

feet deep.

The country rock of the region, like that at the North Hardin 

mine, a mile to the northwest, is hornblende gneiss. The mica-bearing pegmatite is inclosed in a smaller mass of biotite-mica gneiss 

that is included in the hornblende gneiss. The pegmatite is conformable with the schistosity of the inclosing formations, which 

strike due northeast and dip 50° SE. at this point. The pegmatite 

is about 7 feet thick as exposed at the surface. The interior is fine 

grained or is like coarse granite, but along the walls the crystallization is much coarser. Most of the mica obtained is reported to have 

teen taken from the footwall, along which sheets of massive quartz, 

some of them 2 feet thick, were found. It is said that the pegmatite that lay below a depth of 15 feet was coarse grained and contained more mica than that found nearer the surface. The mica was 

of clear rum color and of the best quality.
176 MICA DEPOSITS OF THE UNITED STATES.

The quartz streaks along the footwall of the pegmatite contained 

crystals of beryl that ranged in diameter from less than an inch to* 

6 or 8 inches. These crystals were of good golden and aquamarine 

color though cloudy and only translucent. They made attractive 

gems for scarf pins, cuff buttons, and like ornaments, when cut en 

cabochon.

HARRIS OR DUNCAN MINE.

The Harris mine is 200 or 300 yards southwest of the North Hardin 

mine, or about 1£ miles west of Beaver Creek. The large dumps 

show that considerable work was done here in the early days of mica 

mining in Ashe County. The mine was operated by two shafts, one 

reported to be 90 feet deep, and several open cuts and trenches. 

During 1906 and 1907 the dumps were carefully worked over for 

small-sized sheet mica. The mica has a clear light rum color and is 

of the best quality.

GGODMAN MINE.

The Goodman mine is about three-quarters of a mile southeast 

of Beaver Creek. No work has been done at this mine in recent 

years, and the openings have fallen in badly. The country rock 

at the mine is mica gneiss and strikes about northeast. There was 

much feldspar and quartz and 2 or 3 tons of scrap mica on the dump 

in 1904. The mica was partly specked, and only small blocks, none 

more than 6 inches in diameter, had been left.

WALNUT KNOB MINE.

The Walnut Knob mine is 2 miles N. 40° W. of Elk Crossroads 

and three-quarters of a mile south of Black Mountain. The mine 

has been operated at different times, and the remains of prehistoric 

workings can be seen around it. The principal recent workings at 

the time the mine was examined, in 1906, when it was worked by 

Theodore Westall, were two shafts, one about 35 feet deep, several 

open cuts, and a 50-foot tunnel run from the hillside below.

The body of pegmatite is irregular in form, but its general course, 

which conforms with that of the schistosity of the inclosing mica 

gneiss, is nearly northeast and it dips about 75° SE. In the deeper 

shaft its course is conformable with the schistosity of the mica gneiss 

to a depth of about 25 feet, where it is offset or elbows out to the 

northwest about 15 feet and cuts across the mica gneiss, as shown in 

figure 46, A. A few feet northeast of the shaft, in a room worked 

out of the pegmatite, the latter is seen to pinch out as shown in 

figure 46, B. The tunnel southeast of the shaft encounters pegmatite, 

however, which may be another mass or a branch of the main body. 

Broken outcrops of pegmatite appear on the surface for 75 feet!
NORTH CAROLINA. 177

Mica 

gneiss

These outcrops probably do not come from a single large mass below 

but from streaks of pegmatite in the mica gneiss. On the northwest 

side of this outcrop there are masses of white quartz containing 

mica. Very little quartz was encountered in the workings. The 

;streak of mica last developed followed the west wall of the pegmatite 

in the shaft and was from 1 foot to 4 feet thick. The mica has a 

 clear yellow-brown to light rum color and is of the finest quality. 

It was roughly split by girls in a shop at the mine before shipment. 

A view of the trimming shop is shown in Plate XX, B. Beryl that 

is almost of gem quality and columbite are said to have been found.

About 100 yards southwest of the main workings an incline about 

30 feet long was sunk on the west wall of an irregular mass of pegmatite. The biotite gneiss at this point strikes about north and has 

a variable dip. The east wall of the pegmatite as exposed dips 45° E. 

and may be another body of pegmatite or a part of the irregular 

mass. Streaks of mica were 

found along both walls. A 

streak of biotite gneiss is included in the pegmatite about 

2 feet from the east Avail, parallel to it. The streak of mica 

on this side lies between the 

biotite gneiss and the wall and 

is very rich in small-sized mica.

Two other mica prospects

have been Opened Southeast of FIGURE 46. Plan of Walnut Knob mica mine,

the Walnut Knob mine, one a 

third of a mile and the other 

a half a mile away. At the first prospect, owned by Graham & Westall, the pegmatite is included in biotite gneiss (granite?), which 

strikes N. 30° E. and dips 70° SE. At the other prospect, on G. H. 

Danbury's land, the pegmatite includes massive white quartz. John 

.Ray is reported to own a mine about half a mile south by west of the 

Walnut Knob mine, close to the Watauga County line.

AVERT COUNTY. 

MEADOWS MINE.

The Meadows mine is a little more than 1 mile N. 32° W. of Plumtree, at the foot of a steep mountain slope on the west side of North 

Toe River valley. It is an old mine, first opened by Sam Landers 

about 1875, and has been worked intermittently during many years. 

It is owned and operated by W. W. Avery, of Plum tree. The workings consist of the openings shown in figure 47.

Pegmatite

Ashe County, N. C. A, Offset in pegmatite ; B, pinch in one arm of pegmatite.
178 MICA DEPOSITS OF THE UNITED STATES.

The mine is equipped with steam engine, hoists, air compressor 

and drills, and trimming house. The fuel is cordwood, which is obtained from the mountain side to the west and slid down several 

hundred feet in a board flume or chute to a point near the engine 

house. A general view of the mine taken about 150 yards to the south 

is shown in Plate XXI, A.

The country rock is muscovite-biotite gneiss, which is highly 

schistose near the pegmatite, and which strikes east and has a variable

Trimming 

house 

Boarding 

house

I \Engine 

I I house

-*2S- -Strike and dip ofsrr&r?> 

FIGUKB 47. Plan of Meadows mica mine, 1 mile north of Plumtree, N. C.

1. Small open cut with a tunnel from the west end, now caved in; little to be seen.

2. Short tunnel opening into a large stope nearly 200 feet long and 100 feet wide. 

This stope is on an incline from 20° to 25° N. and contains some rooms 20 feet high. 

Pillars were left where necessary to support the roof. A mine car and track are used 

to carry waste rock to the dump. The stope north of the entrance is lower than 

the tunnel and that south is higher.

3. Large tunnel or stope from the west side of a small open cut. The tunnel i» 

about 75 feet long.

4. Tunnel about 100 feet long. This tunnel is about 35 feet lower than tunnei 

No. 3 and about 45 feet lower than the main working or No. 2.

dip. The pegmatite is in part conformable with the inclosing gneiss, 

striking east. It is a large folded bed, and the axis of the fold lies 

along the south side of the large stope in working No. 2. On the 

north side of this axis the bed dips north at an angle of about 25°; 

on the south side it dips about 25° south. The pegmatite is at least 20 

feet thick in the upper part of workings No. 2 and in workings No. 3. 

It pinches to a thickness of 2 feet at the bottom of the large stope 

No. 2. Small overlapping lens-shaped bodies of pegmatite are in-
NORTH CAROLINA. 179

closed conformably in the gneiss near the large mass of pegmatite. 

The lowest tunnel, No. 4, cuts the pegmatite on its dip to the south.

Streaks of mica were found near both the footwall and the hanging 

wall. These were reported to be equally rich. Good mica was found 

also in the mass of the pegmatite between these streaks, and a few 

crystals lie close to the mica gneiss walls. The mica averages a good 

size and crystals are found more than 20 inches in diameter. It has 

a brownish color and some of it is partly specked. Clear mica is 

reported to have been obtained from tunnel No. 3, but most of that 

from the large stope is more or less specked. The crystals have a 

good flat cleavage and the mica is flexible, making it adaptable to 

electric use.

DOUBLEHEAD MINE.

The Doublehead mine is about 1 mile N. 70° W. of Plumtree. According to information furnished by Ben Aldrich in 1896 the deposit 

of mica here was found by George Shade about 1870, and was opened 

by C. W. Burleson. A few years later it was profitably worked by 

Ben Aldrich, and in 1891 by W. W. Avery. Since that time it has 

been worked in a small way at intervals.

The mine consists of open cuts, pits, and tunnels dug continuously 

for a distance of nearly 200 yards in a N. 25° E. direction along the 

west slope of a hill. The country rock is biotite gneiss, which has a 

variable dip and strike. Near the north end of the workings the 

gneiss strikes north and dips 50° W. in one opening. Near the south 

end a strike of N. 25° W. and a variable dip approximating about 25° 

NE. were measured. The pegmatite is not conformable or is only 

partly conformable with the inclosing gneiss. In places it is lenticA"q peuado SUM ^isodep siq^ qsijxftig; O^-BSJ ^d-eQ v\ Suipaoooy

 Snp U88q si3q 9utm puaqajqnOQ oq^ qotqAv TIT 9§pT.i 9qj 

jo do^ eq^ Sucre 'q^jou eq^ o^ ^mo sdoio UOTUI in^uoo o^ suiaas 

MOJOO rana qsniAiojq-^j'ep v, suq 'j-B9p qSnpq^ 'TJOIUI 

9ures oq^ uo 9q o^ a^edd'B j^e ^ou op sSuiuedo eq^ pu'B 

Col. Milton English and C. W. Burleson. It was operated nearly 

continuously for eight years and has since been intermittently worked 

by others. Capt. English said that the output up to 1896 had sold 

for more than $100,000, but Mr. Benson Grindstaff placed it at 

$37,000.

ALFRED OR VANCE MINE.

The Vance mine, or the old Alfred mine, is half a mile west of 

Plumtree in a hillside at the level of a small stream. The workings 

extend for about 250 feet along the outcrop and are chiefly open cuts. 

The more recent workings are an open cut and an incline on the south-
180 MICA DEPOSITS OF THE UNITED STATES.

east end of the outcrop. A bucket pump operated by a water wheel in 

a branch near by was used to keep the mine dry.

The country rock is biotite gneiss striking N. 30° W. and dipping 

about 35° SW., and with it the pegmatite is conformable. Where 

exposed in the open cut the pegmatite is about 12 feet thick. The 

mica has a dark greenish-brown color and some is partly specked. 

The quantity found is said to be satisfactory.

MILTON ENGLISH MINE.

The Milton English mine, which is about a mile northeast of Plumtree, furnishes some striking examples of the occurrence of typical 

pegmatite in lenses. The pegmatite lies in one of the smaller bodies 

of biotite gneiss that are included in the large area of hornblende 

gneiss which forms the country rock of the region. The rocks exposed in the mine lie nearly horizontal, showing only a few gentle 

monoclinal folds, which dip southward.

A tunnel has been driven southward for a distance of more than 

"450 feet, and from this tunnel drifts have been run both to the east 

and to the west for distances of 25 to 60 feet. The tunnel was carried 

back by a series of rooms, some of them about 25 feet wide where the 

" vein " was very rich. The size and shape of these rooms depended 

on the size of the pegmatite lenses that were removed in mining the 

mica. In some places all the pegmatite had been removed on one side 

of the room or the other. In other places a streak a few inches thick 

was left in the walls, showing where the lens had pinched down from 

the height of the room to a few inches. Cross sections of the lenses of 

pegmatite can be seen in the walls and faces of the workings. Some 

are 6 to 10 inches thick and 2 feet long; others are 5 or 6 feet thick 

and of proportional or even greater length. These lenses overlap or 

lie parallel to one another. Many of them lie in the same stratum of 

gneiss, though they may be several feet apart. A thin seam or parting that contains in places a little pegmatite can generally be traced 

between two such lenses. Here and there the pegmatite occurs in 

sheets or streaks, which in places bulge out into lenses. These streaks 

may pinch down to mere threads, but when followed a little way they 

open out into lenses. The full thickness of the belt of overlapping 

and parallel pegmatite lenses and streaks is generally, less than 8 feet. 

The mica gneiss curves around swells and bulky parts of the lenses.

From the mouth of the tunnel the outcrop of the pegmatite has 

been traced both east and west for some distance around the mountain side. A diabase dike, which the miners; call " the iron bar," follows the pegmatite back as far as work has been carried. It is very 

irregular, cutting into the pegmatite in one place and then not appearing again for some distance.
NORTH CAROLINA. 181

The texture and composition of the pegmatite are those of very 

coarse granite. The three consistuent minerals are thoroughly mixed 

and have separated out in large masses. Even in lenses only 10 inches 

thick mica crystals 5 or 6 inches in diameter have been found. The 

quality of the mica is excellent. The color is a clear light rum when 

the sheets are about one-eighth of an inch thick. The lamination is 

perfect, and beautiful sheets for glazing can be obtained. The yield 

of mica is satisfactory in view of the quantity of rock removed, and 

a fair proportion of the larger sizes is found.

PLUMTREE MINE.

The Plumtree mine is half a mile east of Plumtree, on Plumtree 

Creek. The deposit mined was discovered by C. W. Burleson about 

1870 and was worked by him for about six months. It was later 

worked by Col. English, Col. Rorison, W. W. Avery, and others, 

and after a period of idleness wasi reopened in 1906 by Burleson 

Brothers. The " vein " was exploited by an open cut on the outcrop, 

a 30-foot incline, and a tunnel or drift run from a lower level. The 

country rock is mica gneiss interbedded with hornblende gneiss, 

and the wall rock is mica gneiss. The pegmatite, which is nearly 

conformable with the inclosing formations, strikes about N. 25° W., 

and dips 10°-25° NE. It is 18 inches to 4 feet thick. The mica 

streak lies near the hanging wall and in places is separated from 

the wall by a vein of quartz 3 to 5 inches thick. The crystals of mica 

are large, some weighing as much as 50 pounds. Many are badly 

crushed and crumpled and are suitable only for grinding. The 

quality of the sound crystals is good. The sheets have a greenish 

cast and are in places slightly specked.

JOHNSON MINE.

The Johnson mine is 2 miles east of Plumtree, on Plumtree Creek. 

The country rock at this mine is hornblende gneiss, biotitic near the 

contact with the pegmatite. The pegmatite is nearly conformable 

with the inclosing gneiss, which lies almost flat at some places and 

has gentle rolling folds in others. The pegmatite ranges in thickness from a few inches to 7 feet and is reported to be richest in mica 

where it is 2^ and 4 feet thick. The main opening consists of a tunnel about 100 feet long, running N. 30° W. for 80 feet and then due 

north for 20 feet. The pegmatite in the last 30 feet of this tunnel is 

7 feet thick and carries little mica. Other tunnels have been run. 

following the deposits of the best mica. The rolling structure of 

the formation can be seen from the two dips and strikes. At the 

entrance to the main tunnel the strike was about N. 70° E. and the 

111375 23 13
182 MICA DEPOSITS OF THE UNITED STATES.

dip 20° N. A little way in the rock was nearly flat, and near the end 

of the tunnel the strike was due north and the dip 15° W.

The mica obtained from this mine is of the finest quality and has 

a rich rum color. One block is reported to have been worth more 

than $100.

CHARLIES RIDGE MINE.

The Charlies Ridge mine is 1£ miles west by south of Plumtree 

and half a mile west of Spear, about 200 yards southeast of the Justice mine. It was discovered about in 1882 or 1883 by Ben Aldrich 

and was worked by him for about six months. It has been operated 

at different times by Samuel Landers, Col. Irby, and W. W. Irby,

,0ft.

40ft. OLD 

TUNNELS

100 feet 

J

FIGURE 48. Plan of Charlies Ridge mica mine, near Spear, Avery County, N. C. Figures 

give derations above mouth of new tunnel. The position of the pegmatite Is shown 

on the 55 and 65 foot levels; also the probable position at the level of the end of 

the new tunnel.

During 1905 and 1906 it was reopened by A. Miller, C. W. Wisler, 

and J. W. Walters. The earlier work consisted of three tunnels and 

some pits. The new work consisted of a tunnel about 230 feet long 

at the time it was visited in 1906. This tunnel was expensive, having been run through very hard rock in a devious course at the rate 

of about 3 feet a week. A plan of the workings showing the position of the pegmatite is given in figure 48. The elevation of the 

mouth of the new tunnel is given as zero, and the other three were 

run in about 40, 55, and 65 feet higher up and to the east. The new 

tunnel rises nearly 30 feet from its mouth to its head and would have 

to be driven about 80 feet farther S. 40° E., to strike the " vein."

The country rock is biotite gneiss, whose dip and strike vary, 

though in general the strike is northeast and the dip southeast. Th«
NORTH CAROLINA. 183

mass of pegmatite is large and is richer in mica near its walls than 

in the interior. A streak of highly foliated biotite schist 3 to 6 inches 

thick extends along the walls.

JUSTICE MIKE.

The Justice mine is 1$ miles west by south of Plumtree and half a 

mile west of Spear, about 200 yards northwest of the Charlies Ridge 

mine. It was discovered prior to 1875 by John Justice and worked 

by him for two years. He employed about half a dozen men to drive 

tunnels and to sink a shaft, which was 55 feet deep. The " vein " 

was 10 to 12 feet thick but did not yield mica of the best quality. A 

large quantity of mica was removed, but as the market for the poorer 

grades was not good then the mine did not pay well.67

The mine was reopened in 1906 by Dr. Buchanan, who drove in 

a tunnel nearly 200 feet to find the old workings. The work was 

not easy for the formation was soft and caved badly. The country 

rock at the mine is garnetiferous biotite gneiss in which the garnets 

are very small. The mica is slightly specked but suitable for electrical uses.

PYATT AND VANCE MINES.

The mines of D. N. Pyatt and Matilda Vance are nearly 4 miles 

east by south of Plumtree, on the summit of the- Blue Ridge Mountains. The Vance mine is about 75 yards N. 50° E. of the Pyatt mine. 

Both mines have been worked intermittently by D. N. Pyatt. In 

the Pyatt mine four parallel streaks of pegmatite were found in one 

place and two streaks in another. The strike of the formations at 

the first place is N. 75° E. and the dip 40° N. In the second opening 

the strike was more nearly northeast. The Pyatt mine consists of 

several pits and shallow shafts, none more than 20 feet deep, and 

three short tunnels. The Vance mine consists of pits only. The 

mica obtained at these mines is of a dark brownish-green color, and 

part of it is much specked with magnetite.

Dark-colored and black specked mica of quality similar to that at 

the Pyatt and Vance mines is said to have been found at the Lineback mine, which is 3 miles north by east of them.

McKINNEY OK FOWDEBMILL CREEK MINE.

The McKinney mine is about 3 miles northwest of Plumtree, on 

the north slope of a .mountain south of Powdennill Creek. The 

workings consist of an open cut nearly 100 feet along the strike of 

the " vein " and not more than 15 feet deep in any part. The pegmatite lies in a streak of biotite gneiss a few yards north of its con87 Information furnished to J. A. Holmes by John Justice in 1896.
184 MICA DEPOSITS OF THE UNITED STATES.

tact with hornblende gneiss, which forms the country rock of the 

region. The pegmatite is conformable with the gneiss and strikes 

due east at the west end of the cut and about N. 80° E. in the eastern 

part. Its dip is about 80° S. Its width averages about 6 feet, though 

it increases to 8 feet or more near the middle of the cut. At a point 

near, the west end the south wall elbows out, causing the pegmatite to 

pinch abruptly from 6 to 4 feet. In general, however, the variations 

in size are more gradual. The pegmatite has been traced by prospect pits for some distance farther east.

The texture of the pegmatite is that of coarse granite, except for 

a width of a few inches along the contact, where it is very fine grained 

and of dark color, there preserving a marked contrast to the rest of 

the mass. A view along the contact of the pegmatite is given in 

Plate XXI, B. The feldspar is chiefly plagioclase. The mica generally occurs near one wall or the other, though some large blocks lie 

near the middle of the " vein." It has a rather dark brown color 

and part of it is somewhat specked. It is fairly plentiful, however, 

and blocks of good size are frequently obtained.

McCOURY AND OTHER PROSPECTS.

The T. H. McCoury mica mine is on the southwest side of Roaring 

Creek, about a quarter of a mile above its mouth on North Toe 

River, 2-|- miles north of Plumtree. A 50-foot tunnel has been driven 

N. 50° W. slantwise across the hornblende gneiss country rock and 

the inclosed pegmatite. The pegmatite is about 5 or 6 feet thick, 

strikes 70° W. and dips 25° S. The mine was reopened during 

1906. The mica is dark-brown. A prospect about half a mile 

southeast of the other was opened by McCoury in 1906. The mica 

found has a dark rum color. It is said that about $450 worth of 

mica was taken from this mine during the summer.

A dark green mica is reported from a mine owned by A. L. Miller and operated in 1906 by Mark Buchanan, on North Toe River 

half a mile above the mouth of Roaring Creek.

Two other mica prospects were reported on the top of the ridge! 

or spur running east from Little Yellow Mountain toward the mouth 

of Roaring Creek. One of these, owned by J. S. Pritchard, is half 

a mile and the other is 2£ miles due west of the mouth of Roaring 

Creek.

BUNCOMBE COUNTY. 

NEW BALSAM GAP MINE.

The New Balsam Gap mine is near the head of North Fork of 

Swannanoa River, about a mile southeast of Balsam Gap. The mine 

is on the face of a cliff about TO feet high, a few feet from a water-
XORTH CAROLINA. 185

fall. The "vein" was worked by an open cut at the foot of the 

cliff, about 60 feet long. A tunnel or stope 15 or 20 feet high was 

then driven back under the cliff on the "vein" for 70 feet. The 

pegmatite was removed to its full width, 6 to 8 feet, and the waste was 

left to accumulate in the bottom of the tunnel for stoping out the 

" vein." above. The country rock is much-folded biotite gneiss, 

striking north and dipping high and irregularly to the west. The 

pegmatite cuts across the schistosity of the country rock with a strike 

"of N. 45° E. and a nearly vertical dip. The pegmatite is very irregular in size and at one place in the roof of the tunnel pinches down to

B

FICURB 49. Plan of New Balsam Gap mica, mine, Buncombe County, N. C. A, Section 

sbowiug pegmatite pinched down to 10 inches and elbowing out abruptly; B, irregularity of pegmatite exposed in end of tunnel; lenticular-shaped cross section witli 

small side stringer and horse of mica gneiss.

a width of about 1 foot, but abruptly elbows out again to a width of 

several feet, as shown in figure 49, A. The irregularity of the pegmatite is further shown by the exposure in the end of the tunnel, of 

which figure 49, B is \ vertical cross section. The pegmatite pinches 

doAvn in its upper part, is large in the middle, and smaller again at 

the bottom. There is an elbow in the " vein " on the west side, where 

a small arm of pegmatite branches off into the mica gneiss. An irregular horse of gneiss was included in the " vein." The pegmatite 

is composed of the usual minerals, which are in places segregated out 

into coarse masses. The quartz and feldspar occur in masses 2 or 3 

feet thick, and the mica is richer in some places than in others. At
186 MICA DEPOSITS OF THE UNITED STATES.

one place in the roof where the pegmatite pinched down to a width of 

2 feet it carries abundant mica. The mica is good and is associated 

with some biotite.

CONNALLY HIKE.

The Connally mine is 4 miles north by west of Black Mountain 

station, on the east side of North Fork of Swannanoa River. The 

country rock is diorite or hornblende gneiss, carrying bands of mica 

gneiss. The mine formerly consisted of cuts and shafts on the hillside about 100 yards above the entrance to a new tunnel. The outcrop of the pegmatite at the old workings was marked by much

Hornblende 

gneiss

Hornblende 

rieiss

EXPLANATION

Hornblende gneiss

l.'vv.y'.-.'V.;! Pegmatite (f gidspar) 

i- v ^i v,| Pegmatite

100 feet VvY' Quartz _i ' - i

FIGURE 50. A, Plan of Connally mine. Buncombe County, N. C.; B, section in east 

wall of tunnel at (a) in A.; C, section in east wall of tunnel at (6) in A. See text 

for explanation of reference figures.

massive quartz. A new shaft sunk near the old workings encountered pegmatite. The new tunnel was driven eastward for nearly 

200 feet. Side tunnels were run near the end, as shown in figure 

50, A. At 1, figure 50, A, a small lens or streak of pegmatite cuts 

across the hornblende gneiss walls of the tunnel. At 2 there is a 

vertical contact of hornblende gneiss on the left and pegmatite on 

the right. For a number of yards at 3 there is hornblende gneiss in 

the bottom of the tunnel and pegmatite in the upper part. At 4 

the pegmatite gives out and hornblende gneiss is encountered. The 

irregular nature of the contact here is shown in figure 50, B, which 

represents the section at (a) exposed on the east wall. The felds-
NORTH CAROLINA. 187

pathic part of the pegmatite forks into mica gneiss. At 5 and 8 

there are irregular streaks of massive quartz. Between 6 and 7 

there is a vertical contact between pegmatite and hornblende gneiss. 

At (&) another large irregular mass of quartz is included in or 

forms a part of the pegmatite. It is shown in cross section in figure 

50, C, as it appears in the east wall of the tunnel.

The feldspar of the pegmatite is badly kaolinized, and it was the 

intention of Col. Connally to test the deposit for kaolin. The 

mica occurs chiefly in the kaolin along the masses of quartz and in 

many places is much crushed. The quantity of mica found in the 

new tunnel was not large, but the old workings on the hill above are 

reported to have yielded well. The mica obtained was of clear lightrum color and good quality.

W. H, BURNETT MINE.

The Burnett mine is about 200 yards north of the Connally mine. 

The pegmatite here was worked by an open cut a number of years 

ago. The country rock is hornblende gneiss and interbedded mica 

schist striking N. 10° E. and dipping 80° W. It is said there were 

prehistoric workings at this mine.

BRUSHY MOUNTAIN MINE.

The Brushy Mountain mine is about a mile west of the Connally 

and Burnett mines, on the end of Brushy Ridge. It is reported to 

have been a good producer and was in operation about 1874 or 1876, 

when it was visited by Prof. Kerr. The last work was done on this 

mine about 1894. Other prospects for mica are reported in the 

mountains near this mine, and another old mine, the Bee Tree Mountain mine, has been opened more recently about 2 miles to the west.

R. K. DAVIDSON MINE.

The Davidson mine is on the Alexander place, 1 mile northeast of 

Swannanoa. The workings are old and consist of an open cut, a 

shaft, and a tunnel. Of the little scrap mica left around the mine 

the greater part was A, though some was clear, had good cleavage, 

and was of nearly the size of the hand.

Considerable work is reported to have been done at the Glass mine, 

about 2 miles north by east of Swannanoa.

GUSTAVINO MINE.

The Gustavino mine is a mile south of Black Mountain station. 

It was worked by an open cut, which was, 18 feet deep in the deepest 

part and about 100 feet long, and two shafts run from the bottom of 

the cut. The " vein " is conformable with the inclosing mica schist, 

strikes N. 35° E., and dips about 70° E. Only a little mica was seen
188 MICA DEPOSITS OF THE UNITED STATES.

on the dump, but that was of light color and apparently of good 

quality.

Mica and gem aquamarine beryl are said to have been found on the 

land of J. F. Keece, 1-| miles southeast of Black Mountain station. 

Considerable work is reported to have been done on the old Bearden 

mine, about 1 mile north by east of Montreat, and a new promising 

prospect is reported about half a mile south of Montreat on a spur 

of the Blue Ridge Mountains. 

BURKE COUNTY. 

BUZZARD ROOST KNOB PROSPECT.

A deposit was opened some years ago on the ridge half a mile east 

of Buzzard Roost Knob, 8£ miles S. 15° W. of Morganton, in the 

South Mountains. The workings consisted of an open cut with a 

short tunnel. The country rock is mica gneiss, which strikes N. 30° 

E. and dips irregularly to the southeast. The pegmatite cuts the 

gneiss with a northerly strike. A ledge of massive white quartz 

about 2 feet thick forms a prominent part of the pegmatite. Clear, 

light-colored sheets of mica 2 inches across were seen around the 

dumps.

BURKHONT PROSPECT.

A small pit was opened in a mica deposit a quarter of a mile south 

of the top of Burkmont Mountain, 5£ miles S. 10° W. of Morganton. 

Clear light-colored sheets of mica 3 to 4 inches across were left 

around the prospect.

In another prospect, 1£ miles S. 10° W. of Burkmont Mountain, 

a little mica was found, most of it of small size but of good quality. 

Beryl crystals an inch in diameter, some of which were translucent to 

transparent light green and yellowish green and a few gold-colored, 

were also found.

A small mica prospect has been opened on the side of Ironmonger 

Mountain, west of Mitchell Gap, 4£ miles southeast of Morganton. 

Small crystals of mica of fair quality were found.

CATAWBA COUNTY.

Mica is reported to have been worked on a small scale north of 

Henry, near the Lincoln County line. The prospects are on the continuation of the belt extending from the northwest corner of Gaston 

County across Lincoln County. Another prospect was opened in 

1916 by J. E. Burleson, of Spruce Pine, N. C., about a mile northwest of Baker Mountain, or about 6 miles southwest of Hickory. 

Clear rum-colored mica was found.
NORTH CAROLINA. 189

CLEVELAND COUNTY. 

W. H. THOMPSON OR WYATT MINE.

The W. H. Thompson mine is 2f miles north of Fallston. It was 

opened by several shafts and by tunnels carried from them. Much 

material has been removed, and as the rock is soft and the timbering 

was probably scant most of the workings have fallen in, causing the 

ground above them to subside several feet. The openings lie within 

an area measuring about 60 yards east and west by 20 yards north 

and south. The country rock is garnetiferous mica gneiss carrying 

kyanite in places. The garnets have not weathered so fast as the 

rock and remain thickly scattered through the residual soil near the 

mine. Some of them measure as much as 1*| inches in diameter. 

The products of this rock weathering consist chiefly of clay through 

which abundant rusty garnets, fragments of hematite, and tufts of 

kyanite impregnated with hematite are scattered. The strike of the 

rock near the mine is nearly east and west with variations to the 

northwest in places, and the dip is nearly vertical. In two of the 

shafts and in the tunnels on the north side of the deposit there were 

ledges and streaks of quartz in the large kaolinized feldspar formation exposed. Blocks of mica several inches in diameter had been 

left in the wall and on one of the masses of quartz. Small blocks 

were included in the quartz itself. The pegmatite appears to occui 

in a short deposit more than 50 feet thick. An opening made about 

20 yards east of the main workings exposed a small body of pegmatite 2 or 3 feet thick that has a northwest strike, thus cutting 

across the apparent strike of the main mass.

The mine has produced a large quantity of good-sized mica of clear 

rum color and excellent quality. The chief difficulties encountered in 

mining were caving formations and the quantity of water that had 

to be pumped from the workings. The last work was done about 

1904 and 1905 by J. E. Burleson, of Spruce Pine, N. C., who reported 

obtaining about $15,000 worth of mica.

CALVIN CARPENTER MINE.

The Calvin Carpenter mine is 1 mile south by west of the southwest corner of Lincoln County. Some of the workings were opened 

Jong ago. The principal work consists of shafts and pits on a pegmatite " vein " striking N. 60° W. and dipping vertically. Another 

deposit of pegmatite was prospected by pits about 75 feet to the 

north. These deposits are inclosed in mica gneiss, into which much 

granite has been intruded. The south " vein " is about S feet thick. 

A streak of massive quartz about 2 feet thick is inclosed in the 

kaolinizing feldspar. Part of this quartz is highly translucent to
190 MICA DEPOSITS OF THE UNITED STATES.

nearly transparent. Little could be learned about the quantity of 

mica obtained, but a study of the small crystals left around the 

mine showed that it is clear rum-colored mica of good quality.

FRASER-ENGLISH PROSPECT.

A prospect was opened by Eraser & English a little more than 

half a mile south by east of Beam Mill. A crosscut trench 12 feet 

deep was run for about 90 feet and a shaft was sunk at the inner end 

of it. The country rock is interbedded biotite gneiss and mica schist. 

Some beds of the gneiss resemble quartz diorite. The formation is 

nearly flat, but shows small rolls or folds. The pegmatite cuts across 

the gneiss with a strike of N. 30° E. and an irregular northwest dip, 

elbowing out at some places into the gneiss from a few inches to a 

foot. The pegmatite is 8 to 10 feet thick. The feldspar has partly 

kaolinized. Quartz occurs in irregular segregations, and there is one 

veinlike streak in the interior. The mica has a clear rum color, 

but at the time of examination only rather small crystals had been 

found.

" ^ M. M. MATJNEY MINE.

The Mauney mica mine is about 1 mile southwest of the old Camp 

Call post office, or 9 miles northwest of Shelby. It was first worked 

more than 35 years ago and has not been worked within 20 years. 

The country rock is much crumpled mica schist-gneiss having a general strike of about N. 45° W. The pegmatite cuts across this with 

a strike of N. 20° E. and a nearly vertical dip. The part exposed 

in the old workings is composed of a band of quartz about 5 feet 

thick with 2 to 4 feet of feldspar, quartz, and mica on each side. The 

mine was worked by an open cut 20 feet deep and 40 feet long and 

a shaft with tunnels, both now fallen in. All the mica on the west 

side of the quartz ledge in the bottom of the open cut was removed 

but only part of that on the east side. The mica is of fine quality 

and has a clear rum color. Specimen sheets measuring a foot across 

have been kept in the Mauney home.

S. J. GREEN MINE.

The Green mine is about 7 miles northwest of Shelby. It was 

worked first in the seventies and again later. The workings have 

fallen in badly. The country rock is mica schist-gneiss striking 

north and dipping 70° W. The vein of pegmatite strikes about 

N. 70° E., as shown by the position of 8 or 10 shafts and pits with 

tunnels. These workings are all within about 60 yards of one another. Streaks of massive quartz as much as 3 feet thick were encountered in the pegmatite. In one of the workings the material was 

obtained from the north wall of one of the quartz ledges. The peg-
NORTH CAROLINA. 191

matite is rich in feldspar, which is more or less kaolinized in places. 

The mica is of good quality and has a clear rum color.

INDIAN TOWN AND CASAR MINES.

The Indian Town and Casar mines are at the north end of Cleveland County, 3 miles east by north of Casar and on the southeast side 

of Casar, respectively. The Indian Town mines cover an area of 

more than a square mile and consist of about a dozen small open cuts 

or shallow shafts, which have caved in badly. The same may be 

said of the deposits near Casar and of one near Carpenter Knob, 

5 miles east of Casar. The country rock of this general region is a 

highly schistose gneiss, of which mica, kyanite, and garnet are the 

constituent minerals. The gneiss in this region has been much folded 

and crumpled and at some places has been intruded by granite. The 

pegmatite bodies opened for mica appear generally to cut across the 

schistosity of the gneiss, though at some places they are conformable 

with it. They range in thickness from 2 to 15 feet and are rather 

irregular in shape. In most of the deposits masses of quartz are 

encountered, generally in the form of ledges or veins in the pegmatite. Few large bodies of feldspar or its alteration product, kaolin, 

are found with the mica. Much of the mica obtained in this region 

is of excellent quality and has a rich rum color. Part has A markings, but large sheets have been cut between the A lines.

E. C. HAMBRICK MINE.

The Hambrick mine is 4 miles west of Shelby. It was worked by 

a,n open cut, a 45-foot shaft, and a tunnel. The "vein" has an 

easterly strike and cuts kyanite-mica schist-gneiss wall rock unconformably. The mica is clear and of good quality. It is said there 

was a large output, though mining was hindered greatly by water. 

Other prospects have been found on the place.

E. R. ELLIS MINE AND OTHERS.

The Ellis mine is 4f miles west of Shelby. It was worked by 

several shafts, one to a depth of 50 feet. The mica was much ruled, 

and some had the A structure strongly developed. Other mica 

prospects are reported on the land of Mrs. McFall and Burl Blanton 

north of the Ellis mine, and on the land of Coach McSwain and R. 

McSwain, 5 miles west of Shelby.

SAM PTJTMAN MINE.

The Sam Putman mine is 5£ miles northwest of Shelby. It was 

last worked about 1892. The workings consist of an open cut along 

the " vein," a shaft in the bottom of the cut, three other shafts,
192 MICA DEPOSITS OF THE UNITED STATES.

tunnels, and a pit. The country rock is mica gneiss, which strikes 

northeast and dips 30° SE. The work on the " vein " was carried 

X. 70° E. The mica is of fine quality and is said to have included 

sheets measuring 18 by 22 inches. About 20 feet north of the main 

 ' vein" another smaller " vein" has been opened, which yielded 

poorer mica and more of the A variety.

A quarter of a mile west of this mine another deposit was opened 

by a cut CO feet long and 18 feet deep in the deepest part on a pegmatite running N. 70° E. The wall rock is mica gneiss, which strikes 

north and dips from vertical to east. The mica is said to have been 

of good quality, and a crystal of beryl measuring 3 by 15 inches is 

reported to have been found.

Two other openings for mica have been made on Putman's place, 

in one of which a quartz ledge formed the prominent feature of the 

" vein."

TOM CABANISS MINES.

Several mica mines and prospects have been opened on the Tom 

Cabaniss place, about 5 miles northwest of Shelby, since 1870. None 

of these have been worked since 1898, and nearly all have fallen in. 

badly. Window panes made of sheets of clear, light-colored mica, 

measuring 10 by 12 inches, were seen in the Cabaniss house. These 

sheets are said to have been in service for 35 years at the time of the 

examination, in 1906.

Mica prospects and mines are reported on the old Abel Poston 

place, a quarter of a mile east of the Cabaniss home; on the lands 

of Joe and Charles Blanton, 4£ miles northwest of Shelby; on the 

lands of J. D. and W. P. Weathers, along the narrow-gage railroad 

from Shelby to Lawndale, about 4£ miles from Shelby; and on the 

land of Mrs. Jane Lutz, 5 miles north of Shelby.

MAYNARD WASHBURN "MINE.

The Maynard Washburn mine is 5 miles west-northwest of Shelby. 

Many of the workings are old, but some were made about 1904. They 

consisted of three shafts, with tunnels, and two pits. There are two 

"veins," one of which, with a strike of about N. 70° W., carries a 

large streak of quartz as a wall on the south side and was opened by 

two shafts, each about 40 feet deep. The other " vein " was opened 

by a shaft and pit and is about 50 feet north of the main workings. 

Much of the mica on the dumps at this mine was of the A variety, 

though some of good quality was seen.

The old T. C. Eskridge mine, now A. Blanton's, is near the Washburn mine and has fallen in badly. The workings consisted of a 

shaft and a cut about 100 yards east of it.
NORTH CAROLINA. 193 

W. F. GOLD MINE.

The Gold mica mine is 6|- miles north by west of Shelby on the 

road to Lawndale. There are two prospects here, one near the 

house and the other one-third of a mile to the south. The one near 

the house had been opened by a pit 12 feet deep, now nearly filled up. 

Part of the mica obtained from this place was badly A lined, but 

some good clear material was obtained.

At the mine one-third of a mile from the house the " vein " had 

been worked for 60 feet on the surface by ground-hog openings, and 

there was another pit 60 yards to the west. The country rock is 

kyanite-mica gneiss, which strikes north and dips 65° E. A granite 

mass lies to the north. The pegmatite cuts the gneiss with an east 

strike and vertical dip. The mica occurs along the walls of a large 

quartz ledge, which in some places is 8 feet thick. At the pit west of 

the main workings the gneiss strikes northwest and dips 50° NE. 

The mica obtained at this mine was of good quality and had a clear 

rum color.

Half a mile east of the Gold mine a 60-foot shaft is reported to 

have been sunk on a mica " vein " at the McAlister mine on Sam 

Putman's place. It is said that all the mica Avas mined and that 

kaolin was found at the bottom of the shaft.

J. H. EOYSTER MINE.

The Royster mine is about a mile northwest of the southwest 

corner of Lincoln County. Two prospects have been opened. The 

one farthest south exposed a promising body of pegmatite, which cuts 

across granite gneiss. The gneiss strikes N. 70° E. and dips 75° N. 

The operations consisted of two shaftlike open cuts, 20 and 25 feet 

deep. Mica of good quality was seen on the dump and large sizes 

are said to have been mined.

Mica has been found and work has been done intermittently at a 

number of other places1 in Cleveland County. V. A. Smith, of 

Golden, N. C., opened a prospect on the J. F. Morrison lands, about 

4 miles east of Lattimore, early in 1916. A shaft was sunk to a depth 

of 35 feet and drifts were run from it in two directions. Mica that 

would cut into sheets measuring 10 by 12 inches is said to have 

been found.

GASTON COUNTY.

Mica was worked on the Matiney Carpenter place, close to the 

Lincoln County line, about one-third of a mile from the northwest 

corner of Gaston County. Other prospects have been opened in this 

vicinity. Considerable work has been done about 8 miles north of
194 MICA DEPOSITS OF THE UNITED STATES.

Kings Mountain. M. M. Carpenter, of Kings Mountain, operated 

some of these mines between 1890 and 1900. He says that the work 

was rarely carried below water level. The occurence of the mica in 

this region is very similar to its occurrence in Lincoln and Cleveland 

counties. The country rock is generally mica gneiss, kyanitic, and 

garnetiferous in places. The pegmatite either cuts the schistosity 

of the gneiss or is partly conformable with it. Masses and streaks 

of quartz occur in some of the pegmatites and not in others. The 

mica obtained is generally the same fine clear rum-colored variety as 

that in the adjoining counties.

HAYWOOD COUNTY. 

BIG RIDGE MINE.

The Big Ridge mine is about 6 miles south by east of Waynesville, 

high up on the southwest side of Lickstone Bald, at an elevation of 

about 4,500 feet. The mine is equipped with air drills and a steam 

pump. The mica-bearing pegmatite is conformable with the mica 

gneiss country rock and is folded with it into an anticline, the axis of 

which strikes about N. 80° E. and pitches 20° or more into the 

mountain side. The angle of the fold is not sharp, yet the legs dip 

about 45° a few rods from the axis. The workings consist of tunnels and drifts along the pegmatite, with stopes and raises between. 

On the north leg of the fold the "vein" has been removed for a 

depth of about 300 feet, but on the south leg it has been worked for 

only about 100 feet. The pegmatite is fairly regular in thickness 

and would probably average 8 feet in a large part of the mine. In 

certain places where the full width of the " vein" has been removed 

rooms 12 to 15 feet high were left. The greater part of the pegmatite, 

has a coarse granitic texture. A peculiar graphic-granite texture has been observed in some parts of the pegmatite, caused 

by a parallel orientation of plates of biotite in a matrix of 

feldspar and quartz. A thin section cut from such a piece showed 

under the microscope, a semimicrographic arrangement of quartz in 

feldspar crystals. The feldspar is largely albite. A large quantity 

of biotite, probably one-fourth or one-third of all the mica in the 

"vein," is found with the clear mica, and in places the two form 

intergrowths with such other. Apatite, hornblende, and garnet are 

the accessory minerals. The mica is of clear light rum color and excellent quality. The mine has been worked for many years and has 

been a good producer, but in some years it is closed during part of 

the winter, as it is then difficult to keep up sufficient steam to run the 

air compressor because of the high elevation.
NORTH CAROLINA. 195 

SHINY MINE.

The Shiny mine is near the head of Alien Creek, !£ miles north 

of Richland Balsam Mountain. It is 450 feet above the creek in the 

steep, cliff-like face of the west valley wall. Access to it was obtained over a rough trail and several sets of ladders. The workings consist of an open cut run northward for nearly 200 feet along 

the side of the mountain and in places 25 feet deep. The country 

rock is very hard garnet gneiss, which has a northerly strike and a 

nearly vertical dip. The pegmatite is conformable with this rock 

and pinches and swells from a few inches to several feet in thickness, and streaks branch out from it. The pegmatite contains 

masses and streaks of quartz. Pyrrhotite is scattered through both 

the country rock and part of the pegmatite. The mica is rather 

thick in parts of the " vein," though only small crystals were left 

exposed from the last operations. Sheets measuring 5 and 6 inches 

across were seen at the old trimming house in the valley below the 

mine. These sheets were of very good quality.

SPRUCE RIDGE MINE.

The Spruce Ridge mine is 6 miles south by west of Waynesville, 

in the point of a ridge leading northward from Spruce Knob on the 

Balsam Divide, between two forks of Alien Creek. The mine is an 

old one which was reopened and operated for a short time in 1905 

by C. H. Wolford.

The deposit has been worked by a dozen or more pits, shafts, and 

ground-hog tunnels dug along the west face of the ridge. The 

country rock is mica gneiss. The mica* occurs in streaks or leads 

in a large pegmatite mass, whose relation to the inclosing gneiss 

was not evident. Horses and streaks of schist are included in the 

pegmatite in places and have a variable strike, some striking N. 

35° W. A number of the mica streaks extend in the same direction. 

The pegmatite is semidecomposed and rather soft. Mica occurs 

abundantly, though chiefly in small crystals. A few of the crystals 

would yield sheets 4 by 5 inches. The mica has a clear rum color 

and is generally of good quality.

I. T. WELLS PROSPECT.

The I. T. Wells prospect is If miles S. 75° E. of the top of Plott 

Balsam Mountain, on the south side of the prominent ridge extending eastward from that mountain. The prospect is at an elevation of about 4,000 feet on a steep hillside. Two small openings 

have been made, exposing a ledge of pegmatite about 4 feet thick, 

which is conformable with the inclosing rock. The country rock
196 MTCA DEPOSITS OF THE UNITED STATES.

is biotite gneiss containing a small amount of kyanite. It strikes 

about N. 40° E. and has a vertical or high easterly dip. The gneiss 

incloses small streaks of pegmatite conformable with its bedding. 

No work had been done on the prospect for more than a year at the 

time of the examinations, and only small crystals were seen on the 

dump or in the " vein." These crystals had a clear rum color and 

were of good quality. One crystal of mica was observed with ruling 

lines developed in three directions that cut portions of the mica into 

triangles.

MARK REECE MINE.

The Reece mine is on the east side of the middle prong of Pigeon 

River, If miles south of Three Forks. The operations consisted of 

three small open cuts on a line running east and west and apparently 

on separate streaks of pegmatite. The country rock is mica gneiss, 

which has a northeasterly strike. The pegmatite in the middle cut 

is inclosed conformably or nearly conformably with the gneiss and 

has a strike of N". 20° E. and a vertical dip. Streaks of mica schist 

and quartz are interbedded with it and small quartz veinlets cut 

across the formations about at right angles to the strike. The pegmatite exposed in the easterly cut was 8 feet thick and contained 

masses of quartz as much as 6 feet thick.

ETHAN COOK MINE.

The Ethan Cook mine is at the headwaters of Pigeon River, a 

little more than a mile northeast of Haywood Gap. The deposit lies 

in the bed of a small branch and has been worked by an open cut 

along its strike. The country rock is biotite-mica gneiss which strikes 

N. 25° E. and dips high to the northwest. The pegmatite is conformable with the inclosing rock and includes parallel streaks of quartz. 

The mica is in the part of the pegmatite that lies between the streaks 

of quartz. A quantity of good mica is said to have been taken from 

the small open cut. The mica has a clear rum color and flat cleavage.

MIDDLE OLD FIELD PROSPECT.

There is a mica prospect on the northeast side of Middle Old Field 

Knob, just south of Shining Rock Mountain, which has been worked 

by a small open cut. The country rock is biotite gneiss, which' 

strikes N. 50° E. and dips 25° NW. The pegmatite, which cuts 

across the country rock with a similar strike but a steeper northwest dip, is 4 to 5 feet thick. Some biotite is associated with tihe 

muscovite, which is of very good quality. Only crystals yielding 

sheets of 2 by 3 inches were seen around the dumps, though good 

sheets several inches in diameter were reported to have been found.
NORTH CAROLINA. 197

The mica crystals are highly transparent transversely to the sheets 

as is evident in many of the small crystals.

SHINING ROCK PROSPECT.

The Shining Eock prospect is in the gap a quarter of a mile south 

of the summit of Shining Rock Mountain. It was opened by a pit 

several feet deep and wide. The country rock is mica gneiss and its 

relation to the pegmatite was not exposed in the working. An 

interesting feature at this place is the large ledge of massive white 

quartz that crops out for about a quarter of a mile along the top of 

the mountain. This ledge, which is 30 to 60 feet thick, extends 

down into the gap within a short distance of the mica prospect.

JACKSON COUNTY. 

BIO FLINT MINE.

The Big Flint mine is about half a mile west of south of Wesner 

Bald and about 200 feet above one of the forks of Cabin Creek. The 

mine was named from the immense boulder-like mass of white quartz 

that marks its outcrop. Several " ground-hog " pits and tunnels have 

been made under the mass of quartz, to the west of it, and on the hillside below it. Large masses of quartz outcrop in the branch about 

100 yards east of the mine. The country rock is mica gneiss, which 

strikes east and dips south. The " Big Flint" mass of quartz is about 

40 feet across and at least 25 feet thick. It does not appear to be connected with any mass below, for excavations made under a large part 

of it from each side have encountered only kaolin and mica. The 

under side of this quartz mass is rounded and is composed of overlapping lenticular and shell-like masses of quartz from an inch or 

two to a foot thick. Fine partings of mica lie in the seams between 

these lenses. The feldspar, which, is entirely altered to kaolin, is 

massive under the quartz. This kaolin also shows lens-shaped layers 

with parting seams or slips about parallel with those in the quartz. 

In the openings west of the quartz mass the feldspar is massive and 

contains streaks rich in small mica crystals. A wall of mica gneiss 

exposed here, probably a horse, strikes north and dips 45° E. The 

mica obtained from this mine is principally in- small sizes but is of 

light color and good quality.

PINEY MOUNTAIN MINE.

The Piney Mountain mine is a mile north of Sugarloaf Mountain, 

in the summit of a small knob. The mine has been worked by open 

cuts, crosscut tunnels, drifts, stopes, and shafts. The positions of 

these workings are shown in figure 51. Work has evidently been done

111375 23 14
198 MICA DEPOSITS OP THE UNITED STATES.

Open work 

Underground

on three separate " veins " with varying, nearly northerly strikes and 

approximately vertical dips. The westerly "vein" was followed 

from the open cut by a drift with a stope to the surface and a shaft 

in the bottom of the open stope. At the end of the drift the pegmatite was only 2 feet thick, but it was still fairly rich in mica. An 

open cut with a shaft in the bottom was made on the middle vein, 

and a stope was driven southward from the cut. A crosscut tunnel 

was also run to the drift on the west " vein " for the easy removal of 

waste. The easterly " vein " was the first opened and the workings

on it have fallen in badly. 

It is reported that the 

mica-bearing part was 

stoped out.

The country rock is 

mica gneiss. It is cut in 

various directions by small 

masses and streaks of pegmatite. The pegmatite 

worked for mica ranges in 

thickness from 1 foot to 

12 feet. The pegmatite 

contains at many places a 

streak of quartz, which is 

oriented parallel with the 

walls. The mine is reported to have been a good 

producer of mica.

RUBY CITY MINE

The Euby City mine 

is on the ridge a quarter of a mile west of 

the Sugarloaf Mountain garnet mill, or " ruby corundum " plant, as 

it is called. The workings consist of a 20-foot shaft and two prospect 

pits. The country rock is mica gneiss, which strikes N. 40° E. and 

dips vertically. The pegmatite is irregularly conformable with the 

gneiss and is not more than 4 feet thick in any part exposed. Crystals of mica weighing 3 to 5 pounds were seen, but many of them 

were marked with the A structure or were ruled. The mica has a 

clear light rum color and is of good quality.

SUGARLOAF MOUNTAIN PROSPECT.

A small prospect was opened on the south side of Sugarloaf Mountain about 200 feet vertically below its summit. The pegmatite is 

inclosed in the very hard garnet gneiss that composes the mountain.

Small ' 

promising vein

pegmatite

_ 

( \OPEHCUT

vein 

pinches

50 Feet

FIGURE 51.- -rian of Piney Mountain mica .mine, 

Jackson County, N. C.
NORTH CAROLINA. 199

Only a few blasts had been made, but mica crystals of clear rum color 

and good quality were found. Most of these crystals were less than 

4 inches across.

OCHEE HILL MIKE.

The Ocher Hill mine is If miles east of Beta on Ocher Creek. None 

of the workings were open at the time of the examination in 1906, 

and all appear to be very old. It is reported that the deposit was 

worked by aborigines but has never been worked by white people.

About half a mile up Ocher Creek from the Ocher Hill mine, on 

the west side of the creek, a few hundred feet above the creek level, 

a small mica prospect is exposed along a little branch on the mountain 

side. The country rock is mica gneiss and is cut unconformably by 

the pegmatite. The " vein," where exposed, ranges in thickness from 

18 to 24 inches. Small crystals of mica of good quality have been 

found.

A deposit of mica has been opened on the north side of the State 

road, about If miles east of Beta by a tunnel, an incline, and a small 

open cut. The pegmatite strikes west by north and the dip on its 

west wall is 70° E. The " vein " is composed of large masses of semidecomposed feldspar containing segregations of quartz and having 

" mica capping." The mica has a light color and is of good quality, 

though much of it is ruled or has the A structure.

PAINTER MINE.

The Painter mine is 2| miles S. 65° E. of Sylva, on the northwest 

slope of a small mountain. The deposit of mica here was opened 

many years ago by two shafts, with drifts, and a tunnel run at a

Old shafts.

* ' " n- ;,' Dipso*±sw.

Pegmatite

11

fj£W TUMNEL 175 FT-LQN6

4 r

FIGURE 52. Section in plane of " vein " at Painter mica mine, Jackson County, N. C.

lower level not connected with the shafts. Later work consisted of a 

tunnel 175 feet long and a stope nearly 200 feet long. The stope, 

which is very irregular, was carried to a depth of 40 feet below the 

level of the tunnel and some 20 feet above. A longitudinal section 

through the " vein," showing tha shape of the workings when examined in 1905, is given in figure 52.
200 MICA DEPOSITS OF THE UNITED STATES.

The country rock is garnetiferous mica gneiss, which has a strike 

of N. 35° W. and a high dip to the southwest. The pegmatite is 

nearly conformable with the inclosing gneiss. The "vein" ranges 

in thickness from 2 to more than 15 feet. A large streak of quartz in 

the middle of the pegmatite in this stope is left as a foot wall for the 

workings. The streak of mica lies between this and the hanging wall. 

More mica might possibly be found by prospecting still further the 

streak of feldspar between the quartz and the footwall. Several 

large blocks of mica were exposed in the face of the stope at the time 

of examination. Most of the mica is clear and of good quality, though 

a small quantity of specked material was seen on the dumps. A strip 

of ruled mica of fine clear rum color, saved as a specimen at the mine, 

measured 2 by 15 inches. It exhibited A structure slightly at each end 

but was perfectly sound in the middle. The mine was being worked 

by a Mr. Tustin at the time it was visited by the writer, when it Avas 

equipped with a hoisting engine and pump at the mouth of the tunnel 

and a track in the tunnel and stope. Since then it has been worked 

on a larger scale with good equipment by E. U. Garrett, whose work 

during several years has been rewarded by a large production of 

mica.

TUSTIN KAOLIN AND MICA MINES.

The Tustin mines are on Tustin Mountain, about 2 miles east of 

Sylva, the kaolin mine on the eastern end and the mica mine on the 

southwestern end, the two being nearly a mile apart. The kaolin 

deposit was worked at two levels, one near the top of the mountain 

and the other on a terrace about 300 feet lower. Large open cuts 

were made at each place, and circular shafts with cribbing walls 

were sunk from the lower one. The cribbing was removed and tho 

shafts were filled up after the kaolin had been mined. An incline 

track connected the two workings. All the kaolin was sluiced down 

from the lower deposit to a mill in the valley beloAv. This mine 

produced a quantity of good kaolin when in operation but had been 

idle for several years when examined in 1905.

The mica mine has been worked from northwest to southeast on 

each side of and on top of the ridge in which it is located. Tho 

workings extend through a vertical height of 150 feet on the north 

west side and 140 feet on the southeast side of the ridge. They 

consist principally of ground-hog tunnels, shafts, and pits. The 

country rock is mica gneiss, which strikes N. 10°-35° E. and 

dips 50° or more to the northwest. The pegmatite cuts across the 

gneiss with a strike of N. 50° W. and a high dip to the northwest. 

Sheetlike masses of quartz occur in the "vein" parallel with its 

walls. At the summit of the ridge one of these masses of quart/ 

has a thickness of 3 to 4 feet and is broken into slabs or blocks l>v
NORTH CAROLINA. 201

a series of joints perpendicular to its walls. A dike of gray porphyritic granite several feet thick cuts into the " vein " on the northwest side of the hill. Little mica was left around the dumps, except 

at one or two places on the southeast side of the hill, where a large 

quantity of small crystals had been found. Only part of these had 

been saved.

A second and nearly parallel " vein" of mica and kaolin was 

opened about 150 feet northeast of this deposit from the summit 

down the southeast side of the ridge through a vertical distance of 

150 feet. Most of the mica obtained was taken from the upper 

openings. A promising body of kaolin was opened by three tunnels 

in the loAver part. The kaolin includes masses and small sheets of 

quartz.

On the south side of Carver Mountain, If miles S. 35° E. of Beta, 

several small prospects have been opened on a deposit of kaolin and 

mica. In the most northerly pit a small, hard body of pegmatite 

was encountered. This body had a strike of N. 10° E. and a high 

dip to the west. In two openings to the south masses of kaolin containing a little mica were found.

E. D. DAVI8 PEOSPECT.

The Davis prospect is close to the road along Tuckasegee Kiver, at 

the mouth of Locust Creek, 1-| miles east by south of Webster. It 

was opened by a small shaft. The mica gneiss country rock strikes 

N. 75° E. and dips 80° SE. The pegmatite cuts across the gneiss 

with a strike of N. 10° W. and a dip of 70° W. It is only about 2 

feet thick and has a streak of quartz in the middle as much as 10 

inches tiiick. Only two small sheets of mica were seen.

On the south side of Locust Creek a mile above its mouth a crosscut trench was made on a mica " vein." The country rock is mica 

gneiss, and the pegmatite is apparently conformable with it.

GEORGE WHITE PROSPECT.

The George White prospect is on the ridge southeast of Cane 

Creek, 2 miles above its mouth and about 4 miles east of Webster. 

The pegmatite cuts across the mica gneiss country rock with a northwesterly strike. Only "mica capping" and small crystals of mica 

were seen around the mine. The quality of the small sheets is very 

good.

ADAMS MINE.

The conditions at the Adams mine, 1£ miles southeast of Webster,, 

in Jackson County, are unique. A granite dike 4| to 8 feet thick 

cuts sharply across the country rock, which is mica gneiss. The 

dike strikes N. 25°-30° W. and dips 55°-70° NE.; the mica gneiss
202 MICA DEPOSITS OF THE UNITED STATES.

FIGURE 53. Section of pegmatite at Adams mica mine, 

Ij miles southeast of Webster, Jackson County, N. C. 

1, Wall rock (mica gneiss) ; 2, pegmatite, mostly 

mica ; 3, granite, rather fine grained Distance from 

wall to wall, 7 feet.

strikes about northeast and dips from nearly vertical to 70° SE. This

granite is light gray to nearly white and is rather fine grained. It

has an even texture and 

shows no banding. The 

dike has been traced 

more than 100 yards 

along the strike by 

prospects, openings, and 

tunnels. On each side 

of the granite throughout its exposure there 

is a streak of pegmatite 

from 1 foot to 2 feet 

thick. (See fig. 53.) 

At some places this pegmatite consists chiefly 

of mica, at others of 

feldspar and some

quartz. The contact between the pegmatite and the granite is irregular and is not sharply defined. Many of the crystals of mica,

especially those near the contact of the pegmatite with the

mica gneiss, have cleavage

planes normal to the walls of

the pegmatite, but they show no

other definite orientation. The

feldspar near the surface has

been to some extent kaolinized.

Most of the blocks of mica are

less than 5 inches in diameter.

The blocks have a clear rum

color, but many of them are

damaged by clay stains between

the laminae. They are plentiful, however, and yield much

punch and scrap material. 

The streak of mica on the

southwest side of the granite

Oiimp

\\ Open cut

Tunnel on 

pegnnatite 

Pegmatite 

not opened

Pegmatite 

exposed in cuts

Fine granite dike 

between pegmatite veins 

> Mica gneiss

Dump

Open

has been brought nearly oppo- Dump

site that on the northeast side

by a fault having a throw

of 8 feet. This fault strikes

north by east and is nearly

vertical. The formations on the east side of it have slipped to the

north a few feet, or those on the west side have slipped to the south.

FIGURB 54. Plan of Adams mica mine, near 

Webster, Jackson. County, N. C., showing 

the geology.
NORTH CAKOLINA. 203

A plan showing the workings and the geology of the deposit is given 

in figure 54.

BOB ASHE MINE.

The Bob Ashe mine is 2£ miles S. 35° E. of Webster. The work 

done consists of two tunnels 40 to 50 feet long, one about 18 feet 

above the other. The country rock is mica gneiss containing beds of 

hornblende gneiss. The body of pegmatite is very irregular, and the 

strike of its main part ranges from northeast to north by west and 

the dip from 30° W. to nearly vertical. It cuts the schistosity of the 

gneiss at many places and follows it for short distances at others. At 

one place the pegmatite forks, one arm standing nearly vertical and 

striking northeast and the other striking northeast and dipping 

about 45° SW. The pegmatite ranges from a thin film to a mass 5 

feet thick. In some places it contains streaks of quartz 12 inches 

thick or more. The mica is of good quality and has a fine rum color.

COX & DAVIES MINE.

The Cox & Da vies mine is about three-quarters of a mile south of 

Cullowhee, Jackson County, on the point of a ridge, 200 or 300 feet 

above the road. The developments consist of open cuts, shafts, and 

tunnels, most of them in bad repair. There are two parallel " veins " 

about 70 feet apart, and both have been worked for about 100 yards 

across the top of the ridge. The mica gneiss country rock strikes 

about N. 80° E. and dips south, and the masses of pegmatite conform 

in a general way, though in places they cut the gneiss,

A tunnel run into the hillside on the north " vein " was examined 

for about 150 feet. The " vein " was generally from 2 to 4 feet thick, 

but in places it swelled to a thickness of 6 or 8 feet. At one point the 

pegmatite was warped, the strike shifting from N. 70° E. to S. 80° E. 

and back again, with a varying southerly dip. It cut across the mica 

gneiss, which at this point had a strike of N. 45° E. and a vertical dip. 

Quartz was exposed only in small masses and ledges in this tunnel. 

The feldspar was partly kaolinized and was easily removed in mining. Quartz was more plentiful in the south " vein." In one of the 

tunnels still open a streak of quartz nearly 2 feet thick was exposed 

in the roof and extended some distance back. Both veins have been 

more or less " ground-hogged " through their whole length by petty 

leasers, who did not care what happened to the mine after their 

leases expired. Mica of excellent quality and in large quantity has 

been removed from each vein. The mica is of a fine clear light-rum 

or wine color and is said to have brought the highest prices.

GREGORY MINE.

The Gregory mine is 1 mile S. 20° W. of Panther Knob, near the 

top of the ridge running south from that mountain to the Cullowhee
204 MICA DEPOSITS OF THE UNITED STATES.

Mountain divide. It was worked by an open cut about 50 feet back 

into the mountain side. On one side of the cut a deeper cut and 

room had been stoped out. The deepest part was probably not more 

than 25 feet deep. The country rock is mica gneiss, which strikes 

N. 30° E. and dips vertically. The pegmatite cuts across the gneiss 

with a strike of about N. 50° W. and a vertical or high southerly 

dip. It is at some places at least 10 feet thick and contained large 

streaks and masses of quartz, one 4 feet through. The contact of the 

pegmatite with the mica gneiss is not sharp and at one exposure 

along the southwest wall was jagged, as shown in figure 55. Small 

mica is plentiful in parts of the "vein", and some rather larger

crystals were left in a pillar over 

the stope. The mica is rum-colored 

and is of good quality.

BOWERS MINE.

The Bowers mine is 1 mile S. 30° 

E. of Panther Knob. The mine is 

in the east face of a steep mountain side, almost a cliff. It was 

worked by an open cut not so wide 

as the pegmatite, run 40 feet into 

the mountain side to a maximum 

depth of 35 feet. A shaft was sunk 

from the inner end of this cut. The 

55. uneven contact of pcgma- country rock is hard mica gneiss,

tite and mica gneiss at the Gregory , . , <,frikp<? >J K*O T? i j:nQ mica mine, Jackson County, N. C. wnicn StriKCS IX. 00 LJ. ana Qlps

70° NW. The pegmatite carries

much quartz and is very hard. Near the top of the cut the pegmatite 

forks, one streak, which has been worked out for several feet, running westward and the other streak, which is larger, running northwestward. The mica is of excellent quality and has a fine rum 

color.

L. C. PRESLEY MINE.

The Presley mine is three-quarters of a mile S. 55° E. of Panther 

Knob, about 2£ miles S. 30° W. of Cullowhee. The workings consist 

chiefly of tunnels and an open cut. The tunnels are run northeastward into a hillside and the open cut runs northwestward along a 

small branch. The country rock is mica gneiss, which strikes about 

N. 25° E. and has a vertical or high southeasterly dip. The workings are evidently on different bodies or branches of the pegmatite. 

The open cut, which runs N. 25° W.; follows the vertical contact 

between mica gneiss on the southwest and a large body of pegmatite 

on the northeast. The pegmatite cuts across the gneiss. The tunnels are about To yards northeast of the open cut and have been
NORTH CAROLINA. 205

Pegmatite

run on at least three different streaks of pegmatite, which are nearly 

conformable with the inclosing gneiss. The probable relations of 

the pegmatite to the workings and to the country rock are shown in 

figure 56. The pegmatite near and in the open cut has a slightly 

schistose structure, corresponding to that of the mica gneiss, and 

is cut by ramifying streaks of quartz. The pegmatite that crops 

out in the branch is hard and, with the mica gneiss, forms a cliff 

just below the mine. The mica obtained is of good quality and in 

parts of the pegmatite that were 

not removed in mining small crystals from 1 inch to 3 inches in diameter are plentiful.

Another prospect, called the 

Spence prospect, has been opened 

about 300 yards southwest of the 

Presley mine, but it was reported 

that work was carried on there for 

only a month and a half.

MRS. HELLER'S MINE.

Mrs. Keller's mine is 1 mile S. 

85° E. of Panther Knob. The 

work done consists of open cuts, 

the deepest only about 15 feet. 

The country rock is mica gneiss, 

which strikes N. 30° E. and dips vertically. The pegmatite is 2 to 4 

feet thick and is conformable with the inclosing gneiss.

Openings had been made on another deposit of mica about 300 

yards to the northeast.

FIGURE) 56. Plan of Presley mica mine, 

Jackson County, N. C.

JUDGE FERGUSON MINE.

The Judge Ferguson mine is about 5| miles S. 55° W. of Webster. 

It is one of the older mines and was reopened in 1906 by Mark Bryson. 

At the time the mine was visited the workings consisted of an old 

open cut, two old shafts run from the surface, an interior shaft 55 

feet deep at the end of the crosscut tunnel, and drifts and stopes. 

The new work consisted of a tunnel 180 feet long, run irregularly 

toward the old workings at a level 65 feet lower than the old tunnel. 

The new tunnel was driven for about 25 feet to cut the pegmatite.

The pegmatite strikes about east and has a vertical dip, cutting 

across the country rock, which is mica gneiss, at a small angle. The 

mica gneiss strikes east by north and has a nearly vertical dip. The 

pegmatite is about 12 feet thick in the old workings and in a part of 

its course contains a large streak of quartz. The mica occurs in the 

streaks of feldspar between the quartz and the wall rock. It has a
206 MICA DEPOSITS OF THE UNITED STATES.

clear light color and much of it is of good quality, though a part of 

it has A structure.

JOHN LONG MINE NO. 1.

The John Long mine No. 1 is a quarter of a mile northeast of the 

mouth of Wayehutta Creek, 4 miles southeast of Webster. It has 

been worked by a tunnel that was carried for 90 feet nearly on the 

strike of the country rock, which is mica gneiss, and was there divided 

into two branches, which were joined about 45 feet farther on, encircling a large pillar. An incline was sunk under the large pillar. 

Some work was done on the outcrop a shaft that passed to one side 

of the underground workings and an old tunnel, now caved in. A 

plan of the workings is shown in figure 57. The pegmatite is so soft

that the tunnels require careful timbering. Nearly all the 

rock in the large pillar except 

a horse of mica gneiss several 

feet thick is pegmatite, and the 

body contains streaks or ledges 

of quartz that lie parallel to 

its general course. Several 

large blocks of mica and many 

small ones were seen in the 

kaolinized feldspar. The mica 

was more or less fractured and 

some of it contained clay stains 

between the laminae. The mica that has not been clay stained has a 

clear rum color.

JOHN LONG MINE NO. 2.

The John Long mine No. 2 is close to the mouth of Wayehutta 

Creek, about a quarter of a mile southwest of mine No. 1. The 

workings consist of a crosscut tunnel 60 feet long, driven from a 

point slightly above the creek level, and a 40-foot drift on the " vein." 

The vein has been stoped out to the surface for 20 feet and has been 

removed to a depth of 10 feet below the level of the tunnel. A plan 

of the workings is given in figure 58.

The country rock is biotite gneiss striking about N. 25° E., and 

dipping nearly vertically. The pegmatite is 10 to 12 feet thick and 

includes a number of streaks of gneiss. The mica is more plentiful 

along the east wall of the pegmatite, where the rock is removed to 

a width of 5 to 8 feet in mining. The streaks of included gneiss 

split the pegmatite into lenses and bands from a few inches to a foot 

or two thick. The formation is fresh and hard from the surface 

down and requires much blasting. The mica is of fine clear rum

. o. in broken I i

FIGURE 57. Plan of Jolm Long mica mine No. 

1, Jackson County, N. C.
NORTH CAROLINA. 207

Pegmatite

Drift and stopa 

rface

color. It is reported that during three months of 1906 rough mica 

worth $400 was obtained.

A prospect has been opened a little more than a mile east of Painter 

on the ridge above the John Long mines. The work consists of an 

open cut and a short tunnel. The pegmatite, which is about 3 feet 

thick, is conformable with the mica gneiss, strikes N. 50° E., and has a 

vertical dip. Sheets of quartz are inclosed in the pegmatite parallel 

with its walls, and the country rock, which is mica gneiss, incloses 

small stringers of pegmatite, which lie parallel with its schistosity. 

Little mica had been left around the workings.

A mine 1ms been opened on the summit of the knob 2 miles east 

of Painter by four pits or shafts. The country rock is mica gneiss, 

which strikes N. 50° E. and dips high to the northwest. The pegmatite is conformable or nearly 

conformable with the inclosing 

gneiss. Streaks of mica schist 

are inclosed in the " vein " parallel with its strike. The mica 

from this mine is of good quality and has a fine rum color.

C. D. BRYSON MINE.

The C. D. Bryson mine is 

on the northwest side of Wayehutta Creek, about 2 miles from 

its mouth. It has been worked 

by several small ground-hog pits 

and tunnels. The country rock 

is mica gneiss which strikes northeast and dips northwest. An intrusion of fine to medium grained porphyritic granite cuts the pegmatite 

and the inclosing gneiss. In one of the openings a streak of pegmatite 

was observed along a contact between mica gneiss and granite. The 

pegmatite is marked by large segregations of quartz, which crop out 

prominently on the surface and were encountered in nearly every 

opening. The mica is of good quality, but few of the larger sheets 

measure more than 4 by 5 inches.

Another " vein " of mica was opened by a small pit about 40 yards 

lower down the hillside. The mica was more or less surface or clay 

stained from exposure to the weather.

WAYEHUTTA KAOLIN AND MICA MINE.

The Wayehutta kaolin and mica mine is on the west side of Black 

Mountain, near the head of Wayehutta Creek, 3 miles due south of 

Willetts. The mine is 300 or 400 feet above the valley, high on the 

side and on the top of a steep ridge. The developments consist of

Approximate scale 

D 25 50 73 ico Feet

FIOUBB 58. Plan of John Long mica mine 

No. 2, Jackson County, N. C.
208 MICA DEPOSITS OF THE UNITED STATES.

an 80-foot tunnel, 45 feet of crosscutting, and two interior shafts on 

the pegmatite, and several trial tunnels and openings that do 

not expose the main body of the pegmatite. Figure 59 shows the 

position of the openings and the formations encountered in each. 

The country rock is mica gneiss, which strikes N. 60° to TO 0 E. and 

has a southeasterly to vertical dip. The pegmatite contains in places

streaks or horses of 

mica gneiss, and its 

contact with the gneiss 

is highly irregular. 

A massive vein of 

quartz 2 feet thick 

was encountered near 

the southeast side of 

the pegmatite. Another vein 3 feet thick 

crops out on the top 

and on the opposite 

side of the ridge, 40 

yards southeast of the 

kaolin deposit. Workings on this quartz 

ledge show that it is 

not directly connected 

with the main body of 

the pegmatite. The 

feldspar of the pegmatite is thoroughly 

decomposed, and in 

places large masses 

have been altered to 

pure kaolin. The upand mica mine, per 12 feet of the 30-

foot interior shaft and 

9 feet of the 10-foot shaft were cut through kaolin. A small quantity 

of clear rum-colored mica was found in parts of the workings.

ROCK MINE.

The Rock mine is three-quarters of a mile south of Sugarloaf Mountain, on the headwaters of Wayehutta Creek. It has been worked by 

an open cut in the mountain side. The country rock is mica gneiss, 

which strikes northeast and dips vertically. The pegmatite exposed 

in the face of the cut is nearly 20 feet across and is conformable or 

nearly conformable with the inclosing gneiss. The pegmatite is 

highly acidic, containing large quantities of quartz and only a little

100 Feet

Contour interval 30 feet 

Mign = mica gneiss 

Peg = pegmatite

FIGURE 59. Plan of Wayehutta kaolin 

Jackson County, N. C.
NORTH CAROLINA. 209

feldspar. A hard, fine-grained, slightly garnetiferous porphyritic 

granite dike several feet thick cuts the pegmatite and has been left 

standing in part of the open cut. This dike cuts across the formation with a strike of N. 50° W. and a vertical to high southwest dip. 

The mine is said to have been a good producer, but as very little sheet 

mica had been left around the workings the quality of the output 

could not be determined.

A mica prospect was opened on the knob southwest of the deep gap 

of Black Mountain. The location is marked by large blocks of 

massive white quartz.

SHEEP MOUNTAIN MINE.

The Sheep Mountain mine is on a spur or ridge of that name on 

the southeast side of Black Mountain, about two-thirds of a mile 

west of Moses Creek. Several tunnels have been driven northeastward into the ridge, but they have caved in so badly that the pegmatite was exposed in only one opening at the time the mine was 

visited in 1905. The country rock is biotite gneiss, which is very 

schistose near its contact with the pegmatite. It is reported that 

good " vein " matter was found in only two of the tunnels but that 

the yield from one of these was very large. Another mass of pegmatite. 8 to 4 feet thick, was opened by a tunnel a few hundred yards 

southeast. This " vein " has a northeasterly strike and is conformable with the inclosing mica gneiss. The mica from the Sheep 

Mountain mine is clear and of fairly good quality. Some biotite is 

associated with it.

WOLF PEN GAP TRAIL PROSPECT.

The Wolf Pen Gap Trail prospect is about 150 yards west of the 

point where the trail to Wolf Pen Gap of Black Mountain leaves 

Moses Creek. The country rock is mica gneiss, which strikes N. 35° 

E. and dips 75° NW. The body of pegmatite is conformable with 

the gneiss, is nearly 2 feet thick, and contains several small streaks 

of quartz, which are parallel with the course of the body of pegmatite.

LEON HOOPER MINE.

The Hooper mine is on the road along Moses Creek, a little more 

than a mile above its mouth. It was worked by an open cut 60 feet 

long and 10 to 18 feet deep, run along the " vein " close to the roadside, and a crosscut tunnel was run under the road to remove the 

waste. The country rock is mica gneiss, which strikes N. 50° E. and 

dips 75° SE. The mass of pegmatite is conformable with the inclosing gneiss and is 5 to 12 feet thick. All the pegmatite was not
210 MICA DEPOSITS OF THE UNITED STATES.

removed from the thicker parts of the mass, only that containing a 

"lead" of pockets being mined. The mica gneiss is very schistose 

near its contact with the pegmatite, which contains a few streaks of 

quartz that lie parallel with its walls. One of these streaks near the 

northeast end of the cut was 18 inches thick but pinched out within 

a few feet. The mica at this mine has a dark-brown color in sheets 

a sixteenth of an inch or more thick but is clear when split into thin 

sheets. Part of it is a little specked.

CEDAR CLIFF MINE.

The Cedar Cliff mine is a quarter of a mile east of the Deep Gap 

of Black Mountain, in the face of a cliff of hard rock. It has been 

operated by an open cut that is nearly ,60 feet high and that extends 

5 to 25 feet back from the face of the cliff. The country rock is 

garnetiferous mica gneiss, which strikes N. 45° E. and dips northwest. The pegmatite cuts across the gneiss with a strike of N. 10° E. 

and a nearly vertical dip. The " vein " ranges from 1 foot to 3 feet 

in thickness and contains streaks of quartz parallel with its walls. 

Other masses of pegmatite crop out in the cliff, and some of them 

appear to contain mica in commercial sizes. The mica is clear and 

of good quality.

HAMP WOODS PROSPECT.

The Hamp Woods prospect is on the southeast end of Sheep 

Mountain, about 200 feet above the road along Moses Creek, where 

a few blasts have been made in hard rock that outcrops on the steep 

hillside. The country rock is biotite gneiss, which strikes N. 50° E. 

and dips almost vertically. The " vein " consists of lenticular streaks 

and masses of pegmatite and quartz, which are nearly conformable 

with the associated gneiss. These segregations range in thickness from 

a few inches to a foot or more and are several feet long. They occur 

in a belt of gneiss about 10 feet thick. The crystals of mica are scattered through this belt but occur more plentifully around the lenses 

of quartz. A block of mica 6 by 10 inches across and 3 inches thick 

was blasted out at the time the place was visited. It was not a perfect piece, however, and would yield only small sheets, for it was 

badly fractured and contained inclusions of quartz.

COWARD MOUNTAIN MINE.

The Coward Mountain mine is near the top of the south end of 

Coward Mountain, on the north side of the valley of Cany Fork. 

The country rock is hard garnetiferous mica gneiss, somewhat schistose near its contact with the pegmatite. The notable features are
NORTH CAROLINA. 211

the occurrence of sheetlike horses of wall rock and streaks of quarts 

parallel to the walls of the pegmatite. The body of pegmatite is 

about 10 feet thick, strikes about N. 45° E., and dips 75° NW., and, 

where seen near the surface, is nearly or quite conformable with 

the inclosing rock. Quartz is the predominant mineral and occurs 

in veins and streaks 1 inch to 2 feet thick parallel to the wall rock. 

Feldspar is nowhere very abundant in the pegmatite and is confined 

chiefly to a streak 2 or 3 feet thick near the hanging wall, where, 

with quartz and mica, it forms the " vein." Horses or sheets of 

schistose wall rock, some of them several inches thick, are included 

in the pegmatite at several places. These horses and the bands of 

quartz and streaks of mica, all parallel to the walls, give the rock a 

banded appearance. Such inclusions of sheetlike horses of wall 

rock and veins of quartz in parallel position are common in this 

region.

This mine has not been worked in recent years. The developments 

consist of a shaft on the "vein," reported to be 30 feet deep, and 

sufficient open-cut work at the surface to give working room on the 

mountain side. The mica is of a clear rum color, and, to judge from 

pieces seen, is of good quality. Biotite is found with the clear mica. 

A little pyrrhotite is scattered through the " vein " and wall rock.

BROWN'S COWAED MOUNTAIN PROSPECT.

A small opening for m,ica has been made on the land of Albert 

Brown, on Coward Mountain, about a mile north by east of Cowarts. 

The deposit is marked by a large outcrop of massive white Quartz 

which trends east by north.

ANDY NICHOLSON MINE.

The Nicholson mine is a few hundred yards south of Johns Creek, 

nearly a mile above its junction with Cany Fork. The workings consist, of two tunnels, a shaft, and small open cuts. The country rock 

is mica gneiss, which strikes N. 20° E. and dips 65° SE. The pegmatite is conformable or nearly conformable with the gneiss, which 

is streaked with small bands of pegmatite near the contact. Quartz < 

is segregated here and there in the " vein," and blocks of it 2 or 3 feet 

thick were left around the workings. Some of these blocks bear 

"mica capping." Only small-sheet or scrap mica was left on the 

dumps, but the large size of the workings indicates that valuable 

mica was found.

J. B. PRICE MINE.

The J. B. Price mine is on the south side of Johns Creek, about 1£ 

miles above its junction with Cany Fork, about 75 feet above the
212 MICA DEPOSITS OF THE UNITED STATES.

road that runs along the creek. The workings consist of a large open 

cut, a shaft 35 feet deep run from the bottom of the cut, a crosscut 

tunnel and stopes connected with the shaft, and two prospect trenches. 

The country rock is mica gneiss, which strikes N. 25° E. and dips 65° 

SE. The pegmatite is nearly conformable with the inclosing gneiss 

and ranges in thickness from about 2 feet in the prospect trenches to 

20 feet in the open cut. Sheetlike inclusions of mica schist or gneiss 

and of quartz, some as much as 4 feet thick, lie parallel with the strike. 

A large streak of quartz forms the northwest wall of the " vein " in 

the open cut and is represented by another streak in the same position 

in the tunnel below. Considerable mica lies near or in contact with 

this streak of quartz, and a little is included in the quartz. Some 

rather large crystals of mica were obtained from this mine, but much 

of it was specked and showed A structure.

A. L. LOVEDAHL PEOSPECT.

The Lovedahl prospect is on the north side of Johns Creek, about 

1£ miles above its junction with Cany Fork, close to the creek level. 

The openings consist of two pits and a small tunnel. The country 

rock is schistose mica gneiss, which strikes N. 15° E. and dips 

vertically in the upper workings and strikes N. 30° E. 25 feet below, 

at creek level. The pegmatite is conformable with the inclosing 

gneiss and contains sheets of quartz which lie parallel with its 

strike. The upper workings are probably not on the same band of 

pegmatite that is exposed in the lower workings. 

%

LEWIS ftTJEEN MINE.

The Queen mine is 3 miles east of Cowart, on the Rich Mountain 

Divide. It was opened by a tunnel on mountain side driven S. 20° 

W. on the " vein." Considerable masses of kaolin and large segregations of quartz were encountered in the workings. Only badly 

weathered mica was seen around the dumps.

FKADT OEEEK MINE.

The Frady Creek or Chastine Creek mine is on Frady Creek a 

quarter of a mile above the point where it empties into Chastine 

Creek, more than 2 miles northeast of the Rich Mountain post office. 

The workings consist of an open cut, pits, and a tunnel. The country 

rock is mica gneiss, which strikes N. 40° E. and dips 40° SE. The 

" vein " is approximately conformable with the gneiss and contains 

sheetlike horses of wall rock from 1 inch to 2 feet thick. The pegmatite is at least Ii5 feet thick and contains streaks of quartz from a 

few inches to 4 feet thick. The mica was most abundant near these
NORTH CAROLINA. 213

streaks. It is clear and has a dark color when in sheets one-sixteenth 

of an inch or more in thickness.

ABBS CREEK MINE.

The Abbs Creek mine is in a steep hillside 450 feet above the level 

of Abbs Creek on its east side, If miles north of Eich Mountain 

post office. The pegmatite is 20 feet or more thick and has a northeasterly strike. Both biotite and nruscovite occur in the " vein." 

Part of the mica has the A structure, though sheets of good quality 

could be obtained between the A lines.

BEAR-WALLOW FORE MINE.

The Bearwallow Fork mine is on the branch of that name 2£ miles 

above its junction with Cany Fork. It is an old mine and the workings have caved in badly. Three open cuts were carried N. 50° E. 

from points near the stream level up a steep hillside. Several blocks 

of massive quartz were seen on the dumps. Horses of mica schist 

inclosed in the pegmatite are exposed in one of the pits. The mica 

has a clear rum color and is of good quality. A little biotite is associated with it.

EAST LAPORT MINE.

The East Laport mine is on a main road, a quarter of a mile northwest of the mouth of ,Cany Fork. The workings consist of several 

shafts, tunnels, and pits. The country rock is mica gneiss, which 

strikes N. 45°-65° E. and has a vertical to high northwest dip. The 

body of pegmatite is large and includes tongues of mica gneiss. 

The outcrop is marked by large blocks of massive quartz. The 

feldspar has largely decomposed to kaolin, but in places the decomposition has been only partial so that crustlike shreds of feldspar 

remain in the kaolin. The mica has a clear rum color and is of good 

quality.

RODA KAOLIN AND MICA MINE.

The Roda mine is on the south side of Tuckasegee River opposite 

the mouth of Cany Fork. The deposit lies in the summit of a low 

rounded hill and has been proved on three sides by tunnels and pits. 

The relative position of these workings is shown in figure 60, A. The 

deposit is covered by massive, coarse sugary quartz, which was also 

encountered in the workings. The first work done here was undertaken in search of mica. It consisted of an opening on the south side 

of the hill and in this a large mass of kaolin was exposed. The 

principal development is a crosscut tunnel on the west side. This 

111375 23 16
214 MICA DEPOSITS OF THE UNITED STATES.

cuts masses of both gritty and very good kaolin and sugar quartz. 

A 40-foot shaft was sunk from the interior of this tunnel and encountered kaolin through its whole depth. A diagram of this tunnel is 

shown in figure 60, B. The tunnel on the east side of the deposit was

Large outtrop £g>e 

sugar qu3i-U<3f

FIGUBH 60. Roda kaolin and mica mine, Jackson County, N. C. A, Plan; B, details of

tunnel 3, shown in (A).

driven 18 feet in a mass of fairly pure kaolin after passing through 

a number of feet of soil.

ISLAND FORD MIKE.

The Island Ford mine is in the loop of Tuckasegee River, onethird of a mile below the mouth of Sol Creek. The deposit here has 

been worked for 150 feet along the strike by open cuts and stopes. 

The country rock is mica gneiss, which strikes east and dips 35° N. 

The pegmatite is irregularly conformable with the gneiss and is 

3 to 7 feet thick. The mica is dark and is partly specked. Much 

of it has the A structure, which, however, is not sufficiently developed 

to spoil the whole crystal.

BICE MICA AND BERYL MINE.

The Rice mica and beryl mine is on a spur of Sassafras Mountain, 

about half a mile N. 10° E. of the top and 2 miles S. 30° W. of Sapphire. It now belongs to Dr. Robert Grimshawe. The work consists of an open cut along the " vein " and some tunnels, now caved in. 

The country rock is hornblende gneiss, which strikes N. 30° E. and
NORTH CAROLINA. 215

dips east about 50°. The pegmatite cuts across the gneiss with a 

north strike and a vertical dip. Two forks of pegmatite were exposed in the face of the cut, one going off in irregular conformity 

with the inclosing hornblende gneiss, as shown in figure 61. Much 

of the mica seen was of the A variety and 

of dark color. Beryl crystals of good size 

and green color were found, and a few 

were reported to have been of gem quality.

Pegmatite

FIGURE 61. Section showing 

fork of pegmatite in Rice 

mica and beryl mine, Jackson County, N. C.

JAKE RICE MINE.

The Jake Rice mine is If miles N. 45° 

E. of Ocala and 1£ miles S. 75° E. of Terrapin Mountain. It has been worked by 

" ground hogging " for a width of about 

100 feet in places and for about 200 

feet up and down the hillside. The mine 

was operated for a few months during 1906. 

The country rock at the deposit is highly 

schistose mica gneiss, near which there 

is some diorite. The gneiss strikes N. 35° E. and dips 40° to 60° E. 

The mica occurs in several streaks of pegmatite that cut the gneiss 

at different angles. Small-sheet mica is plentiful. Its color is dark 

brown and part of it is specked. Some of the sheets do not split well 

but tear across the laminae.

A mica prospect was opened on the land of P. N. Bryson, 3 miles 

S. 20° E. of Whiteside Mountain and a quarter of a mile east of 

Chattooga River. Another strong lead of pegmatite with indications of mica crosses the road 200 or 300 yards north of the Bryson 

prospect.

D. L. WATSON MINE.

The Watson mine is 1| miles N. 40° W. of Ocala. There are two 

sets of openings, which are about 200 yards apart and lie nearly 

along the strike of the formation. The one to the southwest consists 

of an open cut about 70 feet long and 6 to 15 feet deep. The country 

rock is biotite gneiss, which contains numerous streaks and lenses of 

pegmatite. The " vein " is 2 to 4 feet thick and is approximately conformable with the inclosing gneiss, which strikes N. 45° E. and dips 

30° NW. The whole formation is fresh and very hard. The mica has 

a clear apple-green color.

The openings to the northeast consist of two short inclines sunk on 

the dip of the " vein." The relations between the pegmatite and the
216 MICA DEPOSITS OF THE UNITED STATES.

gneiss are very similar to those at the open cut, and the dip and strike 

are the same. The mica, however, has a dark-brown rum color.

THOMAS GRIMSHAWE MINE.

The Thomas Grimshawe mica mine is If miles due east of the top of 

Whiteside Mountain, half a mile northeast of Whiteside Cove. It has 

been idle since about 1880 and the workings had caved in badly when 

they were examined in 1906. It was closed down because of the small 

demand for specked mica at that time. The country rock is finegrained gray granite. The remains of the pegmatite on the dumps 

consist of coarsely jointed or sheared blocks of quartz as much as 2 

feet thick and blocks of orthoclase 8 or 10 inches thick, some with 

graphic intergrowths of quartz. The masses of quartz were sheared 

and broken into subrectangular glassy clear fragments, the largest 

half an inch in diameter. The mica is dark and specked. Some rather 

large blocks were obtained, and Mr. Grimshawe has preserved a sheet 

measuring about 20 inches across. Pratt notes that the accessory minerals from the Grimshawe mine are samarskite, large crystals of beryl 

(some of gem quality), garnet, and black and pink tourmaline.

J. H. ROCHESTER MIKE.

The Eochester mine is one-third of a mile southeast of Ocala post 

office. It comprises two openings on different bodies of pegmatite. 

The one to the northwest is an incline run down on the " vein." The 

country and wall rock is pegmatized mica gneiss striking N. 30° E. 

and dipping 50° SE. The pegmatite is conformable with the inclosing gneiss and is about 3£ feet thick. About four-fifths of it, as 

exposed, consists of quartz. The mica is more plentiful near the 

walls of the pegmatite.

The other opening, 75 yards to the southeast, is the principal one 

and consists of an open cut 10 to 20 feet deep and 50 feet long on the 

outcrop, a crosscut tunnel, and drifts, about 100 feet in all, at a lower 

level and under the open cut. The pegmatite is from 1 foot to 5 feet 

thick, and is conformable with the inclosing gneiss. Massive quartz 

is more or less prominent in different parts of the pegmatite. The 

mica is clear and has a dark-brown color tinged with green.

CHINK KNOB PROSPECT.

South of Chink Knob, near the main road through Canada Township, Jackson County, there is a small opening, several feet deep, 

which is described here only because of the peculiar type of pegmatite exposed. The country rock is mostly mica gneiss but includes 

small masses of granite, which are doubtless outliers of the larger 

intrusive masses in the neighborhood. Some of them in places as-
NORTH CAROLINA. 217

sume a coarse, pegmatitic texture. The prospect reveals a vein of 

pegmatite 3^ to 4 feet wide, which strikes about N. 5° W. and dips 

75° to 80° E., cutting one of the masses of coarse granite just mentioned. (See fig. 62.) The 

mica gneiss country rock, 

a few rods from the prospect, strikes N. 55° E. and 

dips 50° NW.

The vein consists largely 

of quartz. On each side 

and down through the interior of this quartz there 

is a streak or band of 

feldspar and mica. The 

interior band consists of 

feldspar and a small quantity of mica, but the bands 

between the walls and the 

quartz probably contain 

more mica than feldspar. 

The quartz is massive and 

of a dark smoky color. It 

has a sheety columnar jointing about normal to its walls, probably 

caused by rock movements. Most of the mica is wedge shaped and of 

the A variety. It is of a dark, smoky color and partly specked. 

Blocks from 3 to 5 inches across were probably the largest found 

during the prospecting.

JIM WOOD MINE.

The Jim Wood mine is on the west side of Wolf Creek, about a 

quarter of a mile above the Wolf Mountain road. The workings

FIGURE 62. Section of pegmatite at mica prospect 

near Chink Knob, Jackson County, N. C. 1, 

Coarse granite; 2, mica and feldspar; 3, quartz, 

jointed; 4, feldspar with little mica.

Pegmatite

FIGURE 63. Sections at Jim, Wood mica mine, Jackson County, N. C. A, Cross section; 

B, section in plane.of the "vein."

consist of an open cut about 50 feet long and an open incline run 

20 feet deeper from the bottom of the cut. The country rock is 

mica gneiss and contains a layer of gritty talc schist a few feet
218 MICA DEPOSITS OF THE UNITED STATES.

southeast of the " vein " of pegmatite. The " vein " is conformable 

with the inclosing gneiss, which strikes N. 70° E. and dips 50° N. 

The " vein " was rich in mica near the surface for the whole length 

opened, but at a point near the bottom of the incline was rich enough 

to work for a width of only 8 feet, though at the bottom of the incline the "pay streak" became wider again. The pegmatite was 

not all removed, only that part of it which carried the streak of 

mica having been mined. The workings and the geologic relations 

are shown in cross and longitudinal section in figure 63, A and B. 

The mica has a dark-brown color in sheets of sufficient thickness, and 

part of it is specked. Some of the crystals are well developed; 

others are wedge shaped.

PINHOOK GAP MINE.

The Pinhook Gap mine is on the southwest side of Pinhook Gap, 

in Tennessee Ridge. The deposit here has been worked extensively 

at different times. In 1905 a new deposit was opened about 250 

yards southwest of the old workings. C. H. Wolford operated the 

Pinhook Gap mine during parts of 1905 and 1906 and reported a 

production of about 600 pounds a week of merchantable sheet mica 

for a part of this time.

The older workings consist of a large open cut from the southwest 

corner of which a crosscut tunnel was driven a short distance into 

the pegmatite and thence turned along the strike of that rock. This 

tunnel connects with another driven in at a lower level. Other short 

tunnels were driven from the open cut in different directions. Numerous pits and crosscut trenches were made a short distance to the 

northeast. The body of pegmatite is irregular, swelling from a 

thickness of a few feet on its southwest side to a thickness of 30 

feet in the open cut and to nearly 50 feet at a point northeast of it. 

Segregations and streaks of quartz are scattered through it. On the 

east side of the open cut a mass or boss of garnet-mica rock or 

"mica capping" several feet across was encountered. It was composed of bunches of wedge-shaped mica crystals showing A structure, 

and coarse garnet crystals were scattered thickly through it. The 

crystals of mica ranged from a fraction of an inch to 3 inches across, 

and the larger ones of garnet were nearly 2 inches in diameter. 

The garnet crystals constitute at least 25 per cent of the whole mass 

and are found to be fresh and firm on crushing, even if apparently 

badly weathered on the surface.

The later workings consist of a shaft 30 feet deep, a drift from it 

on the vein, and a crosscut tunnel run from the hillside below. The 

country rock is mica gneiss, which strikes N. 40° E. and dips 

40° NW. The pegmatite is conformable or nearly conformable with 

the strike of the gneiss. The outcrop of the " vein " is marked by
NORTH CAROLINA. 219

large irregular-shaped masses of quartz, some of which pinch out at 

slight depth. The masses of feldspar in the pegmatite are also irregular in shape. The feldspar is 6 feet thick at the surface in the 

shaft.

The mica from the Pinhook Gap mine is brownish and is partly 

specked. Large sheets are sometimes obtained, however, from which 

the specks can be eliminated by splitting.

FREEMAN BAIRD MINE.

The Freeman Baird mine is on the west side of Neddie Knob, 

nearly 500 feet above Sols Creek, in Canada Township. It is an old 

mine and was worked by two tunnels, now badly caved in. The 

pegmatite and the inclosing mica gneiss strike northeastward into 

the mountain side. In one of the openings a ledge of nearly solid 

"mica capping" 3| feet thick was encountered. The feldspar formation is large and is associated with massive quartz. Large boulders of quartz are scattered over the surface southwest of the mine. 

A crystal of mica several inches across was seen, but like the smaller 

mica in the " capping " it was partly wedge-shaped and fractured.

MRS. SUSAN BROWN'S PROSPECT.

A small open cut was made for mica in pegmatite on the land of 

Mrs. Susan Brown, on the south side of Neddie Knob. The pegmatite strikes northeast almost conformably with the inclosing mica 

gneiss. Large segregations of quartz were encountered in the workings. The mica has a dark-brown color and part is specked.

JAMES REECE MINE.

The James Reece mine is on the Cathay Gap-Pinhook Gap road, 

between Charley and Wolf creeks. It was opened by a tunnel about 

40 feet long. Large boulders of quartz are scattered over the surface above the outcrop of the pegmatite and a vein of massive quartz 

was encountered in the tunnel. The feldspar formation that incloses 

the quartz and carries the mica is also large. About $500 worth of 

rough split mica is said to have been removed from the mine.

ALBERT BROWN PROSPECT.

#

A small prospect was opened near Brown's camp, a mile east of 

the James Reece mine, along the Cathay Gap-Pinhook Gap road, in 

Canada Township. A large vein of quartz and a little feldspathic 

matter was encountered. " Mica capping " was associated with this 

quartz and a few good blocks of mica are said to have been found.

Some work was done on a mica-bearing pegmatite " vein " about 

half a mile below the Cathay Gap-Pinhook Gap road, on the west
220 MICA DEPOSITS OF THE UNITED STATES.

bank of Wolf Creek, a short distance below the Upper Falls, in 

Canada Township. This " vein " cuts irregularly across the mica 

gneiss country rock, which strikes N. 50° E. and dips 45° NW. The 

pegmatite cuts the country rock with a northwest strike and a southwest dip. The mica is dark green and clear.

A. E. GALLOWAY MINE.

The Galloway mine is on Wolf Mountain near the Wolf Mountain 

post office. It has been opened by a crosscut trench, a small incline 

run from the trench along the " vein," and an open cut, also on the 

" vein " but not connected with the crosscut., The " vein" consists 

of several small bands of pegmatite inclosed by or inclosing streaks 

of mica schist. These bands of pegmatite probably were larger or 

came together in the parts of the mass that were mined for mica, 

for a good yield was reported, and very little mica was seen in the 

small streaks of pegmatite left in the face of the workings.

A small mica prospect has been opened on the Wolf Mountain 

ridge about 1-J miles south of Black Mountain, in Canada Township. 

The country rock is garnetiferous mica gneiss, which strikes N. 65° E. 

and dips 60° NW. The pegmatite is conformable or nearly conformable with the inclosing gneiss. The "vein" contains much quartz 

in the form of streaks parallel with the walls. The crystals of mica 

lie near the walls. A few crystals measuring 3 by 4 or 3 by 5 inches 

were seen.

CAMP MOUNTAIN MICA AND KAOLIN* MINE.

The Camp Mountain mine is a mile west of Pinhook Gap, on the 

trail to Cathay Gap, a few hundred yards east of Tennessee Creek. 

The workings consisted of two tunnels and two pits dug around a 

large outcrop of quartz, but they have fallen in so badly that little 

could be seen. It is said that good kaolin was found in the search 

for mica. Large blocks of sugar quartz similar to those found 

around other deposits of kaolin in this part of North Carolina lie on 

the ground here.

LINCOLN COUNTY. 

THOMAS BAXTER MINE.

vThe Thomas Baxter mine is a little more than half a mile N. 62° 

E. of the southwest corner of Lincoln County, on the south side of 

the main road. The mine is probably the oldest one in this region, 

having been worked, it is said, before 1870. The workings, which 

consisted of several shafts, cuts, and tunnels, have caved in so badly 

that little of the formation is exposed. It is reported that one shaft 

was 65 feet deep and that good mica was found at its bottom. The 

ground-water level in a well near the mine was about 35 feet below
NORTH CAROLINA. 221

the surface. The workings fall within an area that is about 40 

yards wide and that extends east by north for about 75 yards. The 

country rock is much-folded mica gneiss, into which Whiteside granite is intruded a few yards west of the mine. The outcrop of a 

large " vein " or ledge of quartz extends N. 70° E. through the workings. The mica is of the best quality, splits well, and has a clear rum 

color. A large quantity of weathered mica in sheets 2 or 3 inches in 

diameter lies scattered around the mine. It is said that the mine 

produced a great quantity of mica, some of it in sheets measuring 

as much as 10 by 12 inches.

FRANK BAXTER MINE.

The Frank Baxter mine is three-quarters of a mile northwest of 

the southwest corner of Lincoln County. The openings consisted 

of two shafts, which are about 30 feet apart from east to west and are 

connected by a tunnel. The country rock is the highly contorted, 

probably kyanitic mica schist gneiss that is characteristic of much 

of the Piedmont region. In places the gneiss is garnetiferous, bearing on its surface rough, rusted crystals of garnet more than an inch 

in diameter. Some of the mica left on the dump was rum-colored 

and of good quality, but the remainder was a little specked and of 

the A variety.

I. K. WILSON PROSPECT.

The Wilson prospect is 1£ miles north of the southwest corner of 

Lincoln County. Two pits have been opened here about 25 feet 

apart from north to south. Large streaks of quartz were found in 

each. The quartz in the northern pit is 8 feet thick and bears on 

each side a streak of mica that contains many small crystals. The 

wall rock is granite gneiss.

Large quantities of mica are reported to have been mined on the 

old David Lackaye farm, which adjoins the land of I. K. Wilson. 

Prospecting has disclosed deposits of mica on the land of C. D. 

Dillinger, on the old Lincolnton-Rutherfordton road, about onethird of a mile east of the Cleveland County line.

W. A. THOMPSON MINES.

The mines and prospects now owned by the W. A. Thompson heirs 

are about 4| miles northeast of Fallston. There are five or six mines 

and prospects within an area measuring half a mile from east to 

west and a quarter of a mile from north to south. The deposits are 

in an area of garnetiferous kyanitic mica gneiss of the Carolina 

gneiss, which is here strongly folded, strikes prevailingly east to 

northeast, and dips low south to southeast. A few of the bodies of
222 MICA DEPOSITS OF THE UNITED STATES.

pegmatite are conformable with the bedding of the gneiss through 

a part of their course at least, but most of them are unconformable.

The principal mine is about 200 yards northwest of the house, on 

the west side of the road. A prospect was opened 200 yards north 

of this one, and the other mines are farther east. The main deposit 

was opened many years ago and the workings have caved in badly. 

Several pits, shafts, and tunnels were run N. 80° E. for about 75 

yards along the outcrop of the pegmatite. The country rock strikes 

N. 80° E. and dips 20° S. and the pegmatite cuts it with similar 

strike but nearly vertical dip. The mica from this mine has a good 

clear rum color and flat cleavage. Sheets of fairly large size are 

said to have been found.

The other mines and prospects have been worked more recently, 

one being in operation in 1912. The workings consist of pits and 

shafts and of irregular tunnels run from them. The irregularities 

of the workings are due largely to irregularities in the mass of pegmatite. In two of the prospects examined the mass of the pegmatite cuts across the bedding of the gneiss in various directions 

and with varying thickness, and at some places small beds branch 

out from it. The yield of mica from one of these prospects seemed 

fairly large, but as the workings were not deep much of the mica 

was stained with clay. Part of it, however, was of good quality and 

had a clear rum color.

Another mica prospect, called the Parker mine, has been opened 

on land that adjoins the Thompson place on the north, and much 

work is reported to have been done at a mica mine of C. Blanton, 

half a mile north of the Thompson mine.

JOE STAMEY MINES.

Two prospects have been opened on the Joe Stamey place, onethird of a mile west of the W. A. Thompson mine and close to the 

Cleveland County line. At one of these prospects an irregular 

mass of pegmatite strikes about N. 70° E., in conformity with the 

strike of the kyanitic mica gneiss that forms the country rock, but 

 cuts it with a vertical dip, whereas the gneiss dips 20° S. The mass 

of pegmatite is probably not more than 2-| feet across. The mica is 

badly ruled but is of good rum color.

PLATO HOUSER MINES.

The Houser mine is about a quarter of a mile north of the old 

Xiincolnton-Rutherfordton road and one-third of a mile east of the 

Cleveland County line. This mine was last operated in 1903 by the 

Empire Mica Co. A 30-foot shaft had been sunk on the "vein," 

and short drifts had been run from it. In a small pit about 100 feet 

from the shaft the " vein" appeared to have pinched out. The
NORTH CAROLINA. . 223

country rock is much-folded kyanitic mica gneiss. The pegmatite 

has an easterly strike and a vertical to northerly dip. It ranges in 

thickness from a few inches to 4 or 5 feet. The mica has a clear 

light rum color and is of fine quality, though much of that which 

lies near the surface is partly broken and clay stained. There are 

several prospects and another old mine on the Houser place.

BESS MIKE.

A mica mine was worked on the Bess Farm, which adjoins the 

Houser place on the northeast. The openings consisted of a shaft, 

pits, and tunnels. The wall rock is kyanitic, mica gneiss, which 

strikes due east and dips 30° N. The pegmatite appears to be conformable or nearly conformable with the walls. The " vein" has 

been opened for about 100 feet. The mica has a clear rum color and 

is of fine quality.

M. M. HULL MINE.

The Hull mine or Bock Cut mine is about 2-| miles northeast of 

Hull Roads. The work at this mine, which was started about 1891, 

consists of a cut 40 feet long, 20 feet deep, and 5 feet wide. The 

mass of pegmatite strikes N. 70° E. and stands nearly vertical. It 

cuts across the kyanitic mica gneiss country rock, which strikes 

N. 10° E. and dips 50° SE. Small bunches of mica are still left in 

the walls. The mica is of good color and quality, and some sheets 

that measured 10 by 14 inches are said to have been found.

JOHN DILLINGER MINES.

The Dillinger mine No. 1 is 2 miles south of Henry, on the roadside, and No. 2 is on a branch a quarter of a mile west of the road. 

Both were worked in 1905 and 1906 by the Cawood Mica Co. The 

country rock is much-folded kyanitic mica gneiss. The streak of 

pegmatite is irregular and has an easterly strike. Each mine was 

opened by a cut 18 to 20 feet deep. . In mine No. 1 much of the output was A mica, which, however, was of good color and included 

some clear parts. The pegmatite in mine No. 2 contained ledges of 

quartz and most of the mica was found near these ledges. It is said 

that beryl also was found in this mine.

D. C. HEAVNER MINE.

The Heavner mine is 5 miles southwest of Reepsville. It was 

being worked by the Cawood Mica Co. when examined in 1906. The 

workings consisted of an open cut and a shaft. The country rock is 

kyanitic mica gneiss, which strikes north and dips-20° E. The body 

of pegmatite is irregular and is not wholly conformable with the
224 MICA DEPOSITS OF THE UNITED STATES.

gneiss. The mica obtained was of very good quality. Another prospect has been opened on the Heavner place about 150 yards north 

of the house.

M'DOWELL COUNTY.

SOTJRWOOD GAP PEOSPECT.

A deposit of mica near the top of the Blue Ridge, below SourwoocH 

Gap, about 2 miles northeast of Montreat, was tested by Mr. Queenr 

of Black Mountain. Only about ten days' work was done.

A deposit about 3 miles northwest of Woodlawn or 10 miles north 

by west of Marion, was worked on a fairly large scale. This deposit was not visited by the writer.

MACON COUNTY. 

SMITH OR BAIRD HIKE.

The deposit at the Smith or Baird mine, which is about a mile 

west of Franklin, was worked on a large scale by the aborigines. 

The mine was operated in the early days by C. D. Smith, and last 

in 1905 and 1906 by Mr. Eldridge, of Franklin. None of the operators except C. D. Smith found large bodies of mica. Some of the 

later workings cut through layers of scrap mica in old dumps and 

openings, finding scrap mica suitable for electric use. Several shafts 

were sunk near the old openings on the top of the ridge, but none of 

them struck the " vein." One of the later tunnels carried from 

stream level encountered material from ancient workings and could 

not be driven farther because the ground caved badly. About 75 

yards northwest of the shaft, across a small branch, some work was 

done along a quartz ledge striking N. 60° W. The country rook at 

this mine is mica gneiss, which contains biotite and garnet and inclusions of diorite. The mica has a clear rum color and is of good 

quality. Considerable biotite is associated with the muscovite. A 

large sheet of mica measuring 16 by 18 inches is still kept in the 

Baird house near the mine as a specimen of the material obtained by 

C. D. Smith. The early operations at this mine have been well described by Mr. Smith,68 whose description is quoted below:

The ancient works on my own farm are the most extensive I have yet seen 

and are therefore worthy of description. The vein, as I have proved by my 

drifting upon it, has a general strike of N. 73° W.-S. 73° B. So far, however, 

as I have drifted upon it, it runs in a zigzag along this general strike. The old 

excavation commences at a small branch and runs at a right angle from it into 

a ridge that juts down with a gentle slope. The dump material has been

«Smith, C. D., Ancient mica mine in North Carolina : Smithsonian Inst. Kept, 1876, 

pp. 441-443.
NORTH CAROLINA. 225

thrown right and left for the first hundred feet. I tunneled in diagonally and 

struck the vein 60 feet from the branch, and have drifted along it 40 feet. 

Here we reach an immense dump rim, 65 feet higher than the level of the 

"branch, which seems to have been thrown back upon their works. It forms 

At this end a circular rim to the continued excavations higher up the ridge. 

The whole length of the excavation from the branch to the upper end of the cut 

is about 320 feet. The material removed from the upper part of the cut was 

carried up the hill as well as down it. The dump on the upper side of this 

upper part of the cut, and at the widest point, is about 25 feet above the bottom of the excavation, and at this point dump and excavation measure about 150 

feet across. At the upper end of my tunnel the old digging has been carried

 down about 30 feet below the surface. If the excavation at the point just 

mentioned was carried as deep as the work at the upper end of the tunnel; it 

would make the dump heap on the upper side 55 feet higher than the bottom 

of the old works. I have been thus particular in order to show that with 

mere stone implements it must have required a series of years and a large force

 to have accomplished such results.

KASSON OR HOLBROOK MINE.

The Kasson Mining Co.'s mine, operated by C. T. Holbrook, is 

"2 miles N. 55° E. of Franklin. The deposit here has been opened at 

three places within a distance of about 100 yards. The principal 

workings are near the summit of a hill and consist of an old shaft 

and irregular drifts, now badly caved in, a new shaft 72 feet deep, 

and workings on the "vein." The new shaft is 10 feet from the 

41 vein," to which crosscuts were run at depths of 52 and 72 feet. At 

the time the mine was examined (in October, 1910) drifts had been 

run about 80 feet west and 35 feet east from both levels. An air 

shaft was made from the drifts to the surface west of the main shaft. 

A prospect pit or shaft sunk about 30 yards east by north of the 

main shaft exposed a ledge of pegmatite. About 100 yards east by 

north of the main workings a shaft 35 feet deep was sunk in the 

Jiillside some years ago, and recently a tunnel has been started at the 

foot of the hill about 80 feet farther east to cut the " vein" in the 

old shaft.

The country rock of the region is hornblende gneiss and mica 

gneiss, which strike north by west. The " vein " of pegmatite strikes 

about N. 70° E., dips high to the south near the surface, and is about 

vertical in the lower workings of the mine. It is 3 to 8 feet thick and

 contains in the middle a prominent streak of quartz, which is exposed 

in most of the workings. This streak ranges in thickness from a few 

inches to 2 feet. At the east end of the drift on the 52-foot level the 

streak fails, the quartz occurring only in small lenses and masses. 

The mica is in the feldspathic streaks on both sides of the quartz 

streak and is more plentiful nearer the quartz. Where the quartz 

streak fails the pegmatite contains little mica.
226 MICA DEPOSITS OF THE UNITED STATES.

MOORE OR CASE MINE.

The Moore or Cabe mine is close to the east bank of Little Tennessee River, 1£ miles north of Franklin. It was idle at the time it was 

examined in 1906, but has since been operated on a rather large 

scale by the Carolina Mica & Manufacturing Co. In 1906 the workings consisted of an open cut, pits, and tunnels badly caved in. The 

open cut was run westward and the pits and tunnels were turned 

nearly north and south from the west end of the cut. The country rock is mica gneiss, which is folded in a curve that is followed by 

the workings and has a high northeast dip. Massive quartz occurs 

in the pegmatite, and in one opening a " vein " of pegmatite 2£ feet 

thick was exposed. Mica of good quality is reported to have been 

obtained.

JOHNSTON MINE.

The Johnston mine is about a mile northwest of Franklin. The 

deposit was opened first by pits and shafts from which tunnels were 

run N. 70° E. for more than 100 yards. Some prospecting was done 

later still farther to the east. It is reported that the "vein" became poor at very shallow depths. Of the mica left around the old 

workings only small sheets, considerably ruled but of good quality, 

were seen. Some biotite was found with the muscovite.

C. T. BLAINE MINE.

The C. T. Blaine mine, 1-| miles northwest of Franklin, was operated by several openings. The " vein" was traced more than 100 

yards and considerable massive quartz was encountered in the 

openings.

JACOB W. HENRY MINE.

The Jacob W. Henry mine is 2 miles S. 80° E. of Higdonville, on 

a steep mountain slope. Two deposits have been opened. The main 

working consists of a pit 20 feet across and 15 to 20 feet deep. At 

this place there is a large outcropping mass of pegmatite, from 

which a streak of pegmatite 3 feet thick, inclosed in the mica schistgneiss country rock, extends to the northeast. The hanging wall of 

the pegmatite exposed in the cut strikes east and dips 25° S. The 

footwall was not exposed. Mica-bearing sheets or beds that strike 

north and have a nearly vertical dip, occur in the pegmatite. These 

beds are generally about 6 inches thick, but in places they bulge out 

to a thickness of 2 feet. The cleavage of the mica crystals is nearly 

parallel with these sheets. One streak of mica crystals is said to have 

been followed northeastward across the cut. The pegmatite appears 

to form a large irregular body in the gneiss. The mica is partly 

specked.
NORTH CAROLINA. 227 

CORUNDUM HILL MICA MINE.

The mica mine at Corundum Hill is about half a mile southwest 

of the corundum mine at that place. It has been opened by several 

pits, shafts, and tunnels. One of the tunnels, which was driven in 

northwestward for about 150 feet, cut a 4-foot pegmatite "vein," 

not rich in mica. The "vein," which was exposed in different 

workings, had a strike of N. 40° E. and a vertical dip. The mica 

has a dark smoky-brown color in sheets over one-sixteenth of an 

inch thick. Much of it is specked.

MINES ALONG COWEE MOUNTAINS.

Several deposits of mica have been worked along the Cowee 

Mountains within a few miles of Cullowhee Gap. Three of these 

were visited in 1906. The Haskett mine, a mile south of Cullowhee 

Gap, has not been worked since the eighties and the tunnels have 

now caved in badly. An opening was made on a deposit on the 

Haskett land on the summit of Kirby Knob. Both rum and greenish colored specked mica were seen on the dumps.

The Deerlick Gap mine, north of Onion Mountain, consists of 

three pits, opened by J. D. Moore. A body of pegmatite 3 feet 

thick, striking N. 10° W. and dipping 80° W., was exposed in the 

lowest workings. About 100 yards farther north along the strike, 

near the top of the ridge, the " vein " of pegmatite exposed in the 

pits is only about 2 feet thick. This " vein " is conformable with the 

inclosing mica gneiss. Mica of good quality but principally of small 

size and a little biotite were found.

LEDFORD MINE.

The Ledford mine is 2£ miles northeast of Franklin, on Rabbit 

Creek (called Cat Creek on the Cowee topographic map). The 

" vein " of pegmatite here has been worked in a northeasterly direction for about 100 yards by pits and ground-hog tunnels. Three 

good shafts have been sunk along the northwest side of the " vein " 

and tunnels have been run from them. The country rock is mica 

gneiss. The " vein" strikes about N. 55° E. and has a variable dip, 

chiefly to the southeast. At one place it is as much as 8 feet thick. 

At some places it contains large masses of quartz. Much of the 

feldspar of the pegmatite has been altered to kaolin. The mica ha3 

a clear rum color and is of good quality where it is free from clay 

stains. Biotite is associated with some of the, muscovite.

QUIZZENBERRY MINE.

The Quizzenberry mine is about a quarter of a mile northwest of 

the Ledford mine, a little more than 2£ miles northeast of Franklin.
228 MICA DEPOSITS OF THE UNITED STATES.

The work at this mine consists of small shafts and tunnels, now 

badly caved in. The "vein" of pegmatite strikes about N. 60° 

W. and has a vertical to high southwest dip. It includes streaks of 

quartz.

ELMORE MINE.

The Elmore mine is at the head of one of the branches of Eabbit 

Creek, 3| miles N. 45° E. of Franklin. It was worked by an open 

cut run N. Q5° E. and by shafts near the northeast end of the 

cut. A large quantity of material had been removed from the 

workings, but these were badly caved in and little could be seen at 

the time the mine was examined in 1906. The open cut is in decomposed rock, but the shaft encountered hard, unaltered pegmatite. 

The mica obtained is clear and of good quality.

FOX MINE.

The Fox mine, on Watauga Creek, 4£ miles N. 35° E. of Franklin, 

has been operated intermittently by numerous pits, shafts, and tunnels. Apparently a very large body of pegmatite was encountered.

Farther up Watauga Creek, near Eulalie post office, a prospect 

for mica was opened on the land of Mrs. M. E. Henry in 1906. The 

work consisted of a pit and a small, crooked tunnel. Mica of fair 

quality is reported to have been found.

L. J. BAILEY KAOLIN AND MICA MINE.

The Bailey kaolin and mica mine, 4£ miles N. 25° E. of Franklin, 

is owned by Charles Harris, of Dillsboro, N. C. The operations 

here have consisted of prospecting and a small amount of mining 

for mica. The openings consist of two tunnels on the west side 

of the ridge in which the deposit lies and a 40-foot shaft on the ridge. 

Several smaller openings have been made, exposing pegmatite containing mica and kaolin. The country rock is mica gneiss which 

strikes a little north by west and dips vertically. At some places 

the body of pegmatite is conformable with the inclosing rock, but 

at other cuts across it. Only small mica was seen around the dumps, 

though sheets measuring 3 by 6 inches are reported to have been 

obtained.

About 200 yards east of the Bailey mine, across a small branch, 

openings have been made for mica around a large outcropping ledge 

of quartz or a " vein " of pegmatite that strikes a little west of north. 

Mica is reported to have been found here plentifully, though chiefly 

5n wedge and A shaped crystals.

MILL KNOB MINES.

Several deposits of mica have been mined 3 miles N. 30° E. of 

Franklin on the summit and around the sides of a hill called Mill
NORTH CAROLINA. 229

Knob, which rises about 200 feet above the surrounding country. 

The owners of the mines are Messrs. Grindstaff, Billings, Winecoff, 

and Zachary. The workings consist of a large open cut, a shaft 95 

feet deep on the top of the knob, and more than a dozen smaller 

shafts, tunnels, and cuts around the sides of the hill. Some of these 

workings exposed more than one body of mica-bearing pegmatite. 

A tunnel was started into hard rock on the south side of the knob 

but was not carried through to the rich deposit of mica reported to 

have been left in the bottom of the 95-foot shaft. The country rock 

in Mill Knob is mica gneiss having a strike varying from N. 20° E. 

to N. 20° W. and an easterly dip. Most of the streaks of pegmatite 

are conformable with the strike of the inclosing rock. They range 

in thickness from a few inches to 25 feet. The larger " veins " were 

encountered in the workings on the summit of the hill and the 

smaller ones on the northwest side. The smaller "veins" were 

probably branches of the larger. The pegmatite near the outcrop 

has in places been softened by weathering, but the deep workings encountered hard, unaltered pegmatite. At the time the place was 

visited, in 1906, the only operations consisted of a search of the 

dumps for small-sheet mica. The mica at these mines is of good 

quality and is reported to have been found abundantly in some of 

the openings.

SANDERS AND OTHER KAOLIN AND MICA PROSPECTS.

Several prospects have been tested for kaolin and mica 3 or 4 miles 

north-northeast of Franklin. One of these, the Doc. Sanders kaolin 

mine, owned by Charles Harris, of Dillsboro, N. C., is 3£ miles 

N. 20° E. of Franklin. The workings at this mine consist of a crosscut tunnel, a shaft, and several pits and borings which expose kaolin. 

The deposit lies in a ridge that trends southeastward, and has been 

traced by the borings for more than 100 yards up and down the 

ridge. The mica gneiss country rock strikes northwestward along 

the ridge. Higher up on the ridge there is an outcrop of massive 

sugary quartz. Very little mica was found in these prospects.

The Berry mica and kaolin mine is a quarter of a mile northwest 

of the Sanders mine. The workings consist of a tunnel and a series 

of pits and shafts that have been carried for 80 yards up a small 

ridge northeast of the tunnel. The country rock is mica gneiss, which 

strikes N. 50° E., dips vertically and incloses streaks and disconnected lenses of pegmatite, which conform with it in strike and 

dip. Streaks of quartz were encountered in several of the openings. Small plates of mica were seen on the dumps around nearly 

all of the workings. 

111375 23 16
230 MICA DEPOSITS OF THE UNITED STATES.

The kaolin prospect of E. Sanders is a quarter of a mile north of 

the Berry mica and kaolin mine. A few pits and borings were made 

here, with uncertain results. The country rock is mica gneiss. In 

one of the openings a 4-foot streak of pegmatite cuts across the 

gneiss, striking N. 35° E. and dipping 70° SE. Small plates of 

mica were obtained from this opening.

LYLE KNOB MINE.

The Lyle Knob mine is 5 miles a little east of north of Franklin,, 

in the southwest side of Lyle Knob. There are two mines here, the 

Lyle Knob mine proper and the Abernathy mine, which adjoins it 

on the west. Both mines have been owned for several years by the 

Detroit Mining Co. (now called the Lyle Knob Mica Mining Co.). 

Work was first done here on a large scale between 1880 and 1885. 

The principal "vein" crops out near the summit of a spur ridge 

leading southwest from Lyle Knob and on its southeast side. Other 

" veins " lie farther west and northwest. The largest working is on 

the southeast side of the ridge, but a tunnel has been cut through from 

the northwest to the southeast side. There is an open cut and a tunnel, stope, and some large rooms cut into the mountain side. An 

incline with side stopes was sunk on another well-marked bed of 

pegmatite about 200 yards to the north, on the western slope of a 

hill.

The country rock is mica gneiss, which incloses beds of hornblende 

gneiss. The gneisses have irregular strikes and dips, some striking 

N. 55° E. and dipping 20° NW., others striking east and dipping 

75° N., and still others striking N. 60° W. and dipping northeast. 

The largest deposit of pegmatite is at least 25 feet thick. It strikes 

about northeast into the ridge and has a high northwest dip. It 

contains streaks and lenses of quartz and yielded a large output of 

mica. The other "vein," which was opened by the incline with 

stopes, is 3 to 6 feet thick, strikes northeast, and dips about 45° SE» 

Some good mica has been obtained here. Other prospects have been 

opened around these workings but were not examined.

CAMPBELL OE HIGDON HIKE.

The Campbell mine is in a shallow cove or hollow on a steep mountain side about 1£ miles N. 75° W. of the point where the road from 

Webster to Franklin crosses Cowee Gap. Here more than a dozen 

tunnels have been run on probably two or more " veins." The soil 

in places in this cove is deep, especially over the lower part of the 

mine, and contains fragments of sheet mica derived from disintegrated veins of pegmatite. Mining through this soil is made difficult 

by landslides. One recent slide carried a large body of the soil down
NORTH CAROLINA. 231

about 10 feet. At the time the mine was visited, in 1906, two tunnels had been opened in hard rock, an old one in landslide material 

was being cleaned out, and another one, 250 feet long, was being 

driven at the base of the old workings in search of " vein " matter. 

This tunnel was run in a very crooked course to avoid masses of 

loose slide rock, which were struck at several places. In one of the 

hard-rock tunnels a good " vein " of pegmatite about 10 feet thick was 

encountered. It contained a streak of quartz 2 to 5 feet acrosso. The 

mica was obtained from the streaks of partly kaolinized feldspar 

that lay between the quartz ledge and mica gneiss walls. The mine 

has yielded some mica of fine quality and a clear rum color..

BO YD KNOB MICA AND KAOLIN MINE.

The Boyd Knob mine is in a small knob 8 miles east of north of 

Franklin, about 3 miles N. 65° E. of West Mills. The mine, which is 

owned by B. C. Grindstaff, has been opened by three tunnels and 

some pits on the north side of the knob and by several tunnels and 

openings on the south side. The exposures in the tunnels on the north 

side indicate that the pegmatite formation strikes northwestward, 

cutting across the mica gneiss country rock. One of these tunnels, 

which is about 150 feet below the summit and has been driven in 300 

feet, cuts across mica and kaolin bearing formations. Openings at 

the summit of the knob show similar formations associated with 

a ledge of coarse sugary quartz, also striking northwestward. This 

ledge ranges in thickness from 12 feet at the summit to 1 foot in the 

tunnels below, on the south side. The body of pegmatite is of irregular shape and is probably as much as 100 feet thick. The feldspar 

of the pegmatite has thoroughly decomposed to kaolin, which occurs 

in large masses. The mica is both scattered through the kaolin and 

segregated into richer bodies. Most of that mined is in rather small 

crystals of fine quality and a clear rum coJcfl ,

BEASLET MINE NO. 1.

The Beasley mine No. 1, also called "Bradley butt," is half a mile 

east of Mica City. It has been operated by a large open cut, a little 

stoping from the bottom of the cut, and several tunnels at lower 

levels on the hillside. Some of these openings are on different 

branches of the main mass of pegmatite worked in the open cut. 

The open cut is about 200 feet long and has a maximum depth of 30 

feet. One of the tunnels below the cut was run in about 75 yards. 

The pegmatite was as much as 30 feet thick in one part of the open 

cut and pinched down into two small streaks 1 foot and 2 feet wide, 

between which, at the east end of the cut, lay 4 feet of mica gneiss. 

The country rock is biotite gneiss. The pegmatite strikes about east
232 MICA DEPOSITS OF THE UNITED STATES.

and dips 85° S. near the outcrop and 30° S. at a depth of 25 feet. It 

cuts sharply across the gneiss and includes horses of gneiss. The 

rock formations here are unaltered and very hard, requiring much 

blasting. Irregular segregations of massive quartz lie here and there 

in the pegmatite. Some parts of the feldspar have a greenish cast, 

caused by stains from the partial decomposition of the sulphides 

that are scattered through it. A large pocket of mica, which yielded 

some large'sheets of high-grade mica, is reported to have been found 

in the open cut. Much of the mica from the Beasley mine No. 1 is of 

excellent quality and of a clear rum color, but some greenish mica 

that had A structure was found in one of the lower openings.

BEASLEY MINE NO. 2.

The Beasley mine No. 2 is about half a mile south of the Beasley 

mine No. 1, on the south side of a high ridge., The deposit has been 

opened by prospect pits for about 150 yards along the outcrop and 

by a tunnel, drifts, large stopes, and an incline which connects with 

the stopes. The lowest tunnel entering the drifts to the stopes is 

about 75 feet lower than the mouth of the incline entering the stopes 

on the hillside above. The drift from the end of the tunnel is about 

150 feet long, and the farther half of it opens up into the stope above. 

The country rock is mica gneiss, which strikes east and dips 65° S. at 

the mouth of the tunnel. The pegmatite strikes about N. TO 0 W. and 

dips 40° SW. The pegmatite is in places more than 15 feet thick, 

but the entire thickness was not removed in mining. The mica evidently occurred more plentifully within the mass, than along the 

walls. In 1906 these old works were being cleared out preparatory 

to developing new ground. The mica from this mine is of fine quality. Some biotite is associated with it.

BRYSON MICA AND KAOLIN MINE.

The mica mine of James Bryson is 6^ miles west of north from 

Franklin, near Wests Mill. A series of ground-hog tunnels, pits, 

and shafts has been made continuously for 150 yards N. 25° E. and 

about 75 yards farther toward the east, across a small cove. Other 

workings show the same or a similar formation. The country rock is 

mica gneiss carrying a little diorite. Irregular masses of quartz 

several feet thick crop out at several places along the body of pegmatite. The mica, most of it in small sheets, is found in streaks and 

pockets in the pegmatite. The feldspar of the pegmatite has been 

thoroughly altered to kaolin through the greater part of the mass, 

though a few isolated bodies where mica is abundant have not been 

completed altered. The kaolin and mica are of good quality, but they 

have not been developed below a depth of 40 feet.
NORTH CAROLINA. 233 

WEST BROTHERS MINE.

The kaolin and mica mine of J. L. & W. J. West adjoins the Bryson 

mine on the east. The body of pegmatite has been traced for more 

than 200 yards across the West property, chiefly by small pits and 

ground-hog workings for mica. Here, as in the James Bryson mine, 

masses of quartz occur through the pegmatite and in some of the 

openings bodies of good kaolin were exposed.

NEAL BRYSON MINE.

The Neal Bryson mine is a mile south of Wests Mill, on the east 

side of Little Tennessee River, in a small depression in a steep hillside. The deep soil that has accumulated in this depression carries 

mica derived from broken-down bodies of pegmatite. Some groundhog mining for mica has been done in this soil. The principal 

workings consist of an old shaft, drifts and stopes on the vein, a new 

180-foot crosscut tunnel, and a new shaft and other drifts. The 

mouths of the shafts are about 60 feet above that of the crosscut 

tunnel. The stopes from the old shaft extend down to the level of 

the new tunnel. A drift run from this tunnel to the east connects 

with the new shaft on this level and on a small level 15 feet above.

The pegmatite has an irregular easterly strike and a varying dip 

that shows considerable warping. The dip ranges from vertical to 

70° N. at one place to 30° S. at the west end of the workings. The 

" vein " ranges in thickness from 1 foot in one part of the workings 

to 12 feet in others. A quartz streak that varies in thickness as the 

thickness of the pegmatite varies is included in the pegmatite near 

its middle part, where it is more than 3 feet thick. The mica occurs 

in the feldspar between this quartz streak and the mica gneiss walls. 

At the east end of the tunnel the " vein " is richest next to the south 

wall. The quality of the mica from this mine is excellent.

HALL AND WELCH MINES.

The Hall and Welch mines are on opposite sides of the same ridge, 

5 miles N. 60° W. of Franklin, and may well be described together. 

A plan of the workings is shown in figure 64. A shaft was sunk to a 

depth of 80 feet at the Hall mine northeast of the summit of the hill, 

and tunnels were started nearly at stream level and carried in as 

crosscuts and drifts on the " vein " to its bottom. From a higher level 

in this shaft a crosscut was carried northward to extensive workings. 

These workings and the shaft have partly fallen in. A line of pits 

and shafts run farther up the hill shows the position of another 

" vein." Farther south along the summit of the ridge, in the Welch 

property, there is a line of workings on the outcrop, at the east end 

of which there is a shaft 40 feet deep. Openings have been made for
234 MICA DEPOSITS OF THE UNITED STATES.

nearly 250 yards along this lead and carried southwestward farther 

west along the ridge. More than 120 yards to the south and 115 feet 

lower down the hill a new crosscut tunnel has been driven in, cutting the " vein " that forms the crest of the ridge and another " vein " 

about 60 feet south of it. The lower " vein " is 2 to 8 feet thick and 

has also been prospected along the outcrop. Drifts have been run 

both east and west along this body of pegmatite, and a 50-foot raise 

and a stope have been made on the east side of the crosscut tunnel. 

The pegmatite that forms the crest of the ridge is about 14 feet thick 

where it is cut by the tunnel. Two streaks of quartz, 1 foot to 3 feet 

thick, are inclosed in the body of pegmatite parallel with its direction. This body of pegmatite cuts across the mica gneiss country

500 Feet Mign = Mica gneiss 

Peg = Pegmatite

FIOURH 64. Plan of Hall and Welch mica mines, Macon County, N. C. Contour interval

is 25 feet.

rock in parts of its course and has a varying easterly strike and a 

nearly vertical dip. Most of the mica mined has been obtained from 

the two outside streaks of feldspar, which lie between quartz and 

mica gneiss walls, but some has been obtained between the two 

streaks of quartz. The mica obtained from these mines is of fine 

quality and has a clear rum color.

IOTLA BRIDGE KAOLIN AND MICA MINE.

The lotla Bridge mine, 4 miles N. 10° W. of Franklin, has been 

worked for both kaolin and mica. At the time it was examined in 

1907 the deposit was being worked by the Franklin Kaolin & Mica 

Co., and the following description and diagram were prepared at 

that time. Since then most of the kaolin has been worked out and 

the mine is now idle.
NORTH CAEOLINA. 235

The deposit lies in the hill along the west bank of Little Tennessee 

Kiver, near the mouth of lotla Creek. The developments consist of 

eight or ten tunnels, about the same number of shafts and pits, and 

two rather large open cuts. The deepest shaft, which is 65 feet deep, 

was sunk from the summit of the hill at a point 120 feet higher than 

the lowest opening. Two other shafts were sunk to depths of 40 and 

45 feet and connected with underground workings. The workings extend for 550 feet, starting northwestward at the south end, swinging 

northward along the hilltop, and ending with a northeasterly trend 

at the north end. The 

body of kaolin and the 

country rock have the 

same sweeping curved 

trend. The position of 

the workings is shown in 

the sketch map forming 

figure 65.

The country rock is 

mica gneiss containing 

streaks of hornblende 

gneiss. The pegmatite 

is irregularly conformable with the inclosing 

gneiss and may not be 

one continuous body. The 

thickness of the pegmatite body varies from a 

few feet to nearly 100 

feet. At some places the 

feldspar was massive and 

has decomposed to large 

bodies of pure kaolin. 

At others it includes considerable mica and quartz, 

which remain in the kaolin. Large bodies of sugar quartz were 

encountered in the workings, and a large mass crops out on the 

hilltop west of the shafts. Boulders of quartz are scattered over 

the hillside below part of the pegmatite outcrop and lie in the river, 

along the west bank, at the north end of the deposit. The greater 

part of the mica obtained from this mine has consisted of small 

sizes. In 1907, however, one crystal that weighed more than 4,000 

pounds was found in a small tunnel connecting with the 65-foot 

shaft. This crystal, though somewhat irregular in shape, had a 

rough rhombic outline. It measured about 29 by 36 inches and was

100 200 300 FEET

i Shaft O Open cut 

>' Vertical bed

V Tunnel is<es E/ev at/on

PIGDBB 65. Plan of lotla Bridge kaolin and mica 

mine, Macon County, N. C.
236 MICA DEPOSITS OF THE UNITED STATES.

about 4-feet thick. It was not sufficiently solid to yield sheets of 

this size, but it did yield some that were 12 to 18 inches square. It 

was sold in the rough for $1,500. The quality of the mica from this 

mine is excellent and the color is a rich rum.

WINECOFF MINE.

The Winecoff or old Jacobs mine is 2£ miles northwest of Franklin. It has been opened for about 300 yards, in a northwesterly direction, by numerous shafts, pits, cuts, and tunnels. A plan of the 

workings is given in figure 66. At 1 remains of ancient workings 

were found, and later four shafts with ground-hog tunnels were 

made. The pegmatite has a width of about 25 feet where exposed 

in these openings and, is badly decomposed. The principal developments to the northwest were made by the last owner, Mr. Winecoff, 

before 1907. At 2 an open cut exposed a ledge of pegmatite rang500

_J_

1000 Feet 

_J

n Shaft

o Pit

/ Tunnel

\ Strike and dip

FIGURE 66. Plan of Winecoff mica mine, Macon County, N. C.

ing in thickness from 5 feet at the surface to 8 feet in the bottom of 

the cut. At 3 a shaft 35 feet deep encountered a ledge of pegmatite 

inclosing bands of quartz. At 4 and 5 two shafts, reported to be 65 

feet deep, exposed a ledge of pegmatite ranging in thickness from 6 to 

8 feet and containing bands of quartz. At 6 a shaft about 40 feet deep, 

connecting with a crosscut tunnel and drifts, encountered a 6-foot 

streak of quartz, along the sides of which were small streaks of feldspar.

The workings at 1 are probably on a different body of pegmatite 

from that found to the northwest, though a swing in the strike 

(northwest) at 1 might bring the same ledge of pegmatite to 2 and 

other points. The strike and dip of the pegmatite are shown at 1, 

3, and 6. The banded appearance of the " vein " is marked in openings 3 to 6 by streaks of quartz and mica schist in the pegmatite and 

parallel with its walls. Most of the mica obtained has been taken 

from the workings at 1, 4, 5, and 6. Possibly the same body of peg-
NORTH CAROLINA. 237

matite was opened at the old Harris or Raby mine, about 75 yards 

northwest of the Winecoff mine, across a branch. The mica from 

these mines has a clear rum color and is of fine quality.

EABY-SWEET MINE.

The Raby-Sweet mine is 2-| miles northwest of Franklin, about a 

third of a mile southwest of the Winecoff mine. It was worked by 

several shafts and tunnels, the last work being a tunnel more than 

400 feet long, built for drainage. This tunnel connected with two of 

the shafts at depths of 60 and 75 feet, respectively. The country 

rock is mica gneiss. The pegmatite contains masses and streaks of 

quartz and in places was very rich in mica. The mica has a clear 

light run color.

IOTLA MIKE.

The lotla mine, an old mine, 3 miles northwest of Franklin, is on 

the steep mountain side along the north bank of lotla Creek. The 

workings consist of three or more tunnels and a shaft. The size of 

the dumps at these old workings show that the underground operations were extensive. In an open cut among the upper workings the 

pegmatite is at least 20 feet thick and includes horses of mica schist. 

The strike of the mica schist country rock is N. 45° E. and the dip 

is 35° SE. The contact of the pegmatite along one of its walls, at 

least, cuts across the schist with a strike of N. 70° W. and a dip of 

80° & The schist next to the pegmatite also strikes N. 70° W. The 

pegmatite exposed in this opening contains an irregular mass of 

quartz 12 feet thick. Massive quartz was also encountered in the 

underground workings. It is reported that more than 200 feet of 

incline and tunnels was driven from the bottom of the open cut and 

that this work was not connected with the tunnels driven into the 

"vein" from lower down the mountain side. The dumps of this 

mine were being reworked for small sheet mica when visited in 1906. 

The mica has a clear rum color and is of the finest quality.

A deposit of fine rum-colored mica has been tested on the land of 

Samuel Valentine, adjoining the lotla mine property on the west.

N. L. BABNASD MINES.

Two " veins " of mica were opened on the N. L. Barnard place, 3| 

miles N. 60° W. of Franklin, during 1905 and 1906. The most 

northern of these." veins " was tested by two shafts, one near the 

old lotla mine, and by pits for 150 yards N. 70° W. The country 

rock is mica gneiss. The pegmatite is 4 to 6 feet thick, strikes N. 

70° W., and dips vertically. Indications of ancient workings were 

found in one of the shafts. This deposit has since been worked for 

kaolin.
238 MICA DEPOSITS OF THE UNITED STATES.

The other mica "vein" on the Barnard property lies nearly a 

quarter of a mile south of the north " vein " and is called the " ribbonmica lead." It has been opened by tunnels, shafts, and pits for 60 

yards to the top of a ridge. A few hundred yards farther on in the 

.same line another opening exposes a " vein " with the same strike. 

The mica gneiss country rock strikes N. 70° W. and dips 60° S., and 

the pegmatite cuts obliquely across it with a strike of N. 55° W. 

The pegmatite ranges in thickness from 10 to 15 feet and includes 

horses of mica gneiss. Large masses of quartz crop out along the 

" vein " and were encountered in the workings. The mica from the 

Barnard mine is of good quality and has a clear rum color. Large 

sheets have been obtained from each " vein," though much of the 

mica from the ribbon-mica lead has been ruled into strips.

CHALK HILL MINE.

The Chalk Hill mine is 1£ miles east of Burningtown. The operations here have extended for more than 200 yards up the west side 

of a ridge to its top and for 150 yards down its east side. The principal workings and the deepest shafts are on the west side of the 

ridge, considerably below the top. The country rock is interbedded 

hornblende and mica gneiss, which strikes N. 80° E. and dips 75° N. 

The main lead of the mica deposits is parallel with the schistosity 

of the country rock, though small streaks of pegmatite cut the strike 

of the gneiss. Outcrops of massive sugary quartz occur along the 

whole line of openings, and large bodies of it were cut in some of 

the workings. Two or more streaks or " veins " of pegmatite have 

 been developed by the main lead of workings. Thirty yards south 

of the point where the main lead crossed the ridge another streak 

of pegmatite carrying mica was exposed in a cut. The mica from 

this mine is clear and has a beautiful rum color. A little biotite 

is associated with it, and in some places the two are intergrown.

SWEHTOT&TOWlf OE POLL MILLER KIKE.

The deposit of mica at the Burningtown mine, 3 miles S. 55° E. 

of Burningtown Bald, was opened before 1880. It was worked 

intermittently until 1903 and from then until early in 1906 on a 

larger scale by the Flint Mica Co., of Flint, Mich. This company 

equipped the mine with electric-power drills, hoisting machinery, 

and lights. The power drills were discarded during the last year 

of operation and hand drills only employed. Electricity was 

generated by a dynamo and turbine using the fall of a neighboring 

stream. The workings consist of a large open cut, a crosscut tunnel, 

drifts and stopes, and a small prospect tunnel and short drifts on 

the level of the open cut. The drifts from the main crosscut tunnel
/ NORTH CAROLINA. 239

are about 45 feet lower than the open cut. The " vein " has been 

removed above the drift by a large stope extending to the bottom of 

the open cut. An incline st'ope was also driven from the drift to a 

depth of 45 feet. A plan of the workings is shown in figure 67. A 

hoist was located in the drift at the end of the crosscut tunnel.

The country rock is mica gneiss, which strikes N. 70° W. to west 

and dips of 80° N. The pegmatite cuts across the country rock 

Tvith a strike of N. 10° E. and a dip of 55° E. It ranges in thickness from 6 to 12 feet and carries streaks of quartz. One of these 

streaks has a maximum thickness of 4 feet and is near the middle of 

the pegmatite. The mica is obtained from the feldspar streaks 

between the quartz and the mica gneiss walls. The quality of 

the mica from the on. 

Burningtown mine "V^ 

is excellent, and %>, 

the color is a clear 

rum. The output 

is said to have been 

large.

''&m stope

Mign = Mica gneiss 

Pe-.t -Pwnatii-e

5ft. Figures show elevations above 

mouth of crosscut tunnel

-Plan of Burningtown or Poll Miller mica mine, 

Macon County, N. C.

BUTH STALOUP MINE.

The Ruth Stalcup mine is 3 miles

S. 40° E. of Burn- ? 5P I0.° '^OFeet 

ingtown Bald. It 

has been opened 

along the outcrop 

for 50 feet by two 

small cuts and a FlGORB 67-- 

crosscut tunnel 

driven to the " vein." The country rock is mica gneiss. It is cut unconformably by the pegmatite, which strikes about N. 70° E. and 

dips variably to the south. The pegmatite is 6 feet thick and is made 

up in part of streaks of quartz which lie parallel with its course. The 

mica is of good quality and has a clear rum color. Good-sized blocks 

were reported to have been found.

Bear Pen mine. The Bear Pen mine is about 300 yards south- 

-west of the Ruth Stalcup. The deposit here has been worked about 

as much as that at the Stalcup mine.

WAYAH BALD MIKE.

The Wayah Bald mine is on the east side of Wayah Bald Mountain, at an elevation of about 5,000 feet above sea level. The work 

consists of a tunnel that extends nearly 40 feet into the mountain 

side and a small amount of overhead stoping. The country rock is
240 MICA DEPOSITS OF THE UNITED STATES.

niica gneiss, which strikes N. 70° E. and dips 60° NW. The " vein" 

cuts across the gneiss with a strike of N. 45° W. and a dip of 35° 

SW. The " vein," of pegmatite ranges in thickness from 2£ to 4 feet 

where exposed in the workings and incloses a streak of quartz in its 

middle. At one place in the pegmatite the streak of quartz forks, 

nearly inclosing a small mass of feldspar (fig. 68), and in another 

it completely envelops a mass of feldspar 3 or 4 inches thick. The 

mica occurs in the feldspathic streak between the quartz and the 

walls of the pegmatite. The feldspar is partly kaolinized and is 

therefore easy to mine. The mica has a clear rum color and is of 

good quality.

FIGURE 68. Cross section of pegmatite 2£ feet thick at Wayah Bald mica mine, Macotu 

County, N. C. 1, Wall rock (mica gneiss) ; 2, pegmatite, mostly feldspar, quartz, 

and mica; 3, massive quartz.

LYLE CUT OR EVANS MINE.

The Lyle Cut or Evans mine is on the steep side of the ridge that 

extends eastward from Wayah Bald Mountain, about three-quarters 

of a mile northeast of its summit, at an elevation of about 4,300 feet 

above sea level. The working consists of an open cut of the width 

of the pegmatite run about 40 yards back into the mountain side. 

The depth is nowhere more than 35 feet.

The country rock is mica gneiss, which strikes N. 80° E. and dips 

60° NW. The pegmatite cuts across the gneiss with a^ strike of 

N. 40° E. and a dip of about 70° SE. It is 7 feet wide'in places, 

but pinches down to about 3 feet at the entrance to the cut. These 

variations in thickness are rather gradual, and the deposit appears 

to be very regular. The strike and dip remain uniform as far as 

the rock is exposed in the cut. A persistent streak of quartz of 

variable thickness and continuity lies within the pegmatite near its 

middle. It ranges in thickness from 10 inches to 2 feet and extends 

to the full height of the pegmatite exposed in the face of the cut. It 

has a peculiar banding parallel to its direction and to the walls of 

the pegmatite. In hand specimens the texture of the rock is granu-
NORTH CAROLINA. 241

lar and the banding appears as alternating parts of more or less 

translucent and white quartz. Small plates of mica lie in certain 

streaks or seams parallel to this banding. Under the microscope a 

thin section proved to be composed almost entirely of rather fine 

grained quartz. The grains are angular and fit somewhat closely 

together. Some of them show evidence of moderate strain. Between 

crossed nicols a slight banding is apparent in certain directions by 

the extinction of the quartz grains. Parallel to this banding there 

are two streaks of minute black particles, probably magnetite. These 

lie chiefly between separate grains of quartz, though some are included in the grains. The quartz contains many inclusions. Some 

of them seem to be irregular cavities with or without gas; others 

have a reddish color and may be iron oxide that has worked its way 

from the pores between the grain 

into the cavities in the quartz.

The mica was reported to be 

plentiful in the feldspar-quartz 

streak between the quartz band 

and the wall rock. The color is a 

beautiful rum and the quality is 

excellent.

Wall 

(mica gi

rock 

neiss)

^Pegmatite,mostly feldspar, 

quartz, and mica

FIGUKE 69. Cross section of pegmatite 

8 to 10 feet thick at Turkey's Nest 

mica mine, on Wayah Bald Mountain, 

Macon County, N. C.

TURKEY'S NEST MINE.

The Turkey's Nest mine is on 

the north side of the ridge that extends eastward from Wayah Bald 

Mountain about a mile from its 

summit, at an elevation of about 

4,800 feet above sea level. The 

" vein " has been worked for about 50 yards by an open cut in the 

mountain side and by some incline work from the bottom to a depth 

of about 35 feet. The country and wall rock is hard mica gneiss, 

which strikes N. 60° E. and dips 60° NW. The pegmatite was 8 to 

10 feet thick where it was worked in the cut but pinched down to 

small streaks in the end of the cut. It cuts across the gneiss with 

a strike of N. 60° E. and an irregular dip of 45° to 70° SE. A 

prominent streak of quartz is inclosed in the middle of the vein 

(fig. 69) and in places composes half the thickness of the pegmatite. 

The mica occurs in the streaks of feldspar and quartz on either side 

of the streak of quartz. The quality of the mica is good and the 

color is clear rum.

THORN MOUNTAIN MINES.

The Thorn Mountain mines are on the south side of Thorn Mountain, about 3 miles south of Wayah Gap, in the Nantahala Moun-
242 MICA DEPOSITS OF THE UNITED STATES.

tains, in Macon County. There are two mines about a quarter of a 

mile apart on this mountain. Mine No. 1 was worked by an open 

cut 30 feet deep and a tunnel along the strike of the vein from the 

mountain side into the cut. The country rock is biotite gneiss, which 

has a north strike and a high easterly dip. The pegmatite is, in 

part at least, conformable with the inclosing gneiss. The "vein" 

ranged in thickness from 6 feet at the surface to 18 feet in the cut. 

Nearly the whole thickness of the thicker part was removed in 

mining. At mine No. 2 the work consists of a large open cut, which 

was carried back about 40 feet on the strike of the pegmatite and 

is about 25 feet deep at the farther end. The country rock is pegmatized mica gneiss, which strikes about N. 50° E. and has a high 

northwest to vertical dip. The pegmatite is from 10 to 15 feet thick

Mtca gneiss-.wall 

rock and horses

Pegmatite Mica pockets Quartz Solid granular 

mica,in quartz

FIGURE 70. Cross section of pegmatite at Thorn Mountain mica mine No. 2, Macon

County, N. C.

and cuts the grieissic country rock with a strike of about N. 25° E. and 

a dip of 50° SE. (See fig. TO.) At least one horse of mica gneiss is included in it and exposed near the bottom of the cut. This horse is a 

large one, and its schistosity forms an angle to that of the wall rock. 

In the face of the cut just below the top the pegmatite either forks or, 

more probably, includes another horse of wall rock. The schistosity 

of this inclusion is also not parallel with that of the walls. These 

horses are even more highly pegmatized than the country rock, and 

the lower one has a very irregular outline.

The pegmatite has the texture of very coarse granite. The mica 

does not seem to be confined to any one part of it, but is found in 

bunches or pockets in the mass. It is said that in mining often 

several feet of barren " vein " would have to be removed before one
NORTH CAROLINA. 243

of these pockets was encountered. They generally yielded a large 

quantity of mica, however. In the bottom of the cut on the southeast 

side a mass of quartz had been laid bare, but it was not sufficiently 

exposed to disclose its relation to the rest of the pegmatite. An 

irregular band of solid mica, composed of an aggregate of small 

crystals one-eighth to one-half inch or more in diameter, was included in this quartz. It was 6 to 10 inches thick and 8 feet long. 

A little biotite is found with the muscovite at this mine. The two 

minerals are in places intergrown, and in one specimen seen a sheet 

of biotite inclosed a rhombic plate of muscovite, which had very 

much the appearance of a fancy window in a dark wall. A small 

quantity of pyrrhotite carrying a little chalcopyrite is scattered 

through this quartz in lumps of different sizes, some of which weighed 

as much as half a pound.

This mine has not been worked for several years. The "vein n 

material removed was exceedingly hard. The distance of the mine 

from any settlement made it difficult to obtain labor. The mica wasreported to be fairly plentiful, however, and this fact, combined 

with its light color and excellent quality, ought to equalize any 

disadvantage due to location.

ROARING FORE MINE.

The Roaring Fork mine is about 2£ miles S. 35° W. of Wayah Gap 

and a few hundred yards south of Roaring Fork Creek. Two 

" veins " have been worked at this mine by open cuts on the outcrop 

and a tunnel run from one of these. The veins are about 40 feet 

apart and strike N. 10° E. and N. 20° E., respectively, converging 

toward the south. Massive quartz was encountered in each deposit.

WINDING STAIR MINE.

The Winding Stair mine, half a mile northeast of Winding Stair 

Gap, in the Nantahala Mountains, at the head of Cartoogechaye 

Creek, has not been worked for many years. The operations here 

seem to have been confined to an open cut and a tunnel, both now 

badly caved in. The country rock is mica gneiss. Clear rumcolored mica was found.

One mile east of the Winding Stair mine mica prospects have 

been opened on the land of J. W. Greenwood. Half a mile farther 

east other prospects for mica have been opened on the land of W. B. 

Williamson.

DOBSON MINE.

The Dobson mine is 5 miles southwest of Franklin, on Cartoogechaye Creek. The workings extend for about 75 yards N. 35° E. 

There are two tunnels, 15 feet apart, just above stream -level, and
244 MICA DEPOSITS OF THE UNITED STATES.

numerous pits and prospects along the outcrop. The workings are 

old and have caved in badly. Large masses of quartz crop out along 

the line of openings.

A mica and kaolin deposit on the north side of Cartoogechaye 

Creek, about 2£ miles S. 75° W. of Franklin, on a hillside facing 

east, has been opened about 200 feet by three tunnels. The formations encountered were decomposed and the workings have caved in 

badly. The country rock is diorite and badly weathered hornblende 

gneiss. The pegmatite also is decomposed and the feldspar has 

changed to kaolin of apparently good quality but undetermined quantity. The pegmatite contains horses of diorite and inclusions of 

quartz. The mica has a clear rum color.

I. A. DEAL PROSPECT.

The Deal prospect is 1£ miles S. 60° W. of Franklin. Here a 

partly decomposed pegmatite formation, which has a regular strike 

of N. 25° E. and a dip of 70° SE., was encountered. The mica obtained was clear, though in part clay stained by surface weathering.

BASCOM MINE.

The Bascom mine is a little more than a mile S. 20° W. of Highlands. The deposit was opened by a small cut, 15 to 20 feet across, 

near the point of the ridge formed by the outcrop of the pegmatite. 

The rock shows indications of mica for some distance up and down 

the ridge in a northwesterly direction. The mica obtained at this 

mine has a dark color and part of it is specked.

A. W. YOUNG MINE.

The Young mine is on the Blue Eidge, 1£ miles S. 15° W. of 

Scaley Mountain, about 6 miles southwest of Highlands. It was 

worked by an open cut about 70i feet long and 10 to 18 feet deep. 

The country rock is mica gneiss, into which is injected many streaks 

of granite, and has a strike about north and south and a dip of 80° 

E. The pegmatite cuts across the country rock with an east strike 

and a dip of 80° N. The " vein " ranges in thickness from 6 to 12 

feet and contains a streak of quartz 2£ to 3 feet thick. The pegmatite 

pinches and swells and extends out in small branches that are 

conformable with the schistosity of the mica gneiss. Orthoclase feldspar blocks weighing 15 pounds were seen. The mica has a smoky 

brown to green color and part of it is specked. Much of it shows 

wedge and A structure, though good sheets can be cut from between 

the A lines.

A small prospect 75 yards north yields mica that is of the same 

colors but that shows very little wedge or A structure.
WORTH CAROLINA. 245

 ?

MITCHELL COUNTY. 

HAWK MINE.

The Hawk mine is a little more than 4 miles east of Bakersville, 

near the headwaters of Cave Creek. It was not visited by the writer. 

The brief description given here is taken from notes made by J. A. 

Holmes in 1896. The mine was first opened by Buchanan & 

Buchanan in 1870 and was later taken over by Heap & Clapp and 

other parties. It was worked on a large scale at intervals by different parties until 1893^but since that time operations have been confined to working over the old dumps. The Hawk mine is classed 

among the best of the old Heap & Clapp properties, it has been a 

large producer and is credited with a yield of mica worth at least 

$75,000. This mica was of fine quality, and some of it was cut into 

sheets 18 by 20 inches across.

Several shafts with drifts and stopes have been made in different 

parts of the property and long tunnels have been run in from the 

mountain side on the vein. Two shafts, the Tom Green shaft and 

the main shaft, were sunk to a depth of about 250 feet. Most of the 

others were less than 100 feet deep. In places the " vein " has been 

largely stoped out, but in other places work was stopped before the 

stoping was completed because the conditions for mining were unfavorable. More than one " vein " was encountered in the workings, 

but the best one was generally about 8 feet thick, though it showed 

local variations in thickness. Most of the country rock is hornblende 

gneiss of the Koan gneiss formation which incloses a few beds of 

mica gneiss.

CLARISSA MINE.

The Clarissa mine is 2£ miles due east of Bakersville, on the west 

side of a small cove about 200 yards north of Cane Creek. It was 

first worked by Joseph Buchanan and Neal Leatherman about 1870 

but was later purchased by Heap & Clapp, who considered it the 

best of their properties. It has been reputed to be the best mica 

mine in the State. Some question has arisen as to the ownership of 

the property, but the greater part of the deposit appears to be 

owned by Mrs. Ella Clapp Thompson, of Washington, D. C. (a 

daughter of E. B. Clapp), and Mrs. V. P. Cibotti, of Philadelphia^ 

Pa., and part of the east end of the workings is held by Vance 

Brown, of Asheville, N. C. Col. J. K. Irby estimates that up to 

1896 the mine had yielded mica worth about $175,000.

The workings extend from the bed of the stream in the cove about 

150 yards S. 60° W. up to and across the summit of a small ridge that 

stands about 75 feet higher than the stream. Practically nothing

111375 23 17
246 MICA DEPOSITS OF THE UNITED STATES.

^

can be seen of the workings except a depression about 75 yards Iong7 

20 to 30 feet wide, and 5 to 15 feet deep, formed by old surface workings and by the caving of underground workings. A few pits were 

opened between the end of this depression and the summit of the 

hill. Dumps were cast up along the workings, but the principal one 

was at the foot of the hill. Here, at the bottom of the cove, an immense pile, of waste was accumulated, but by being worked over for 

scrap and by washing down in floods it has now been spread out over 

a large area.

Information regarding the early workings was given to J. A. 

Holmes in 1892 by Thomas Grindstaff, Col. J. K. Irby, and a Mr, 

Buchanan, and all this information, supplemented by measurements made by J. A. Holmes, has been abstracted below. The latei 

work at the mine is described by B. B. Westphalen, the mine superintendent, in a report prepared for Mrs. Thompson. Westphalen's 

report is also abstracted below. J. A. Holmes's notes follow:

Remains of prehistoric workings were found around the Clarissa 

mine. These workings consisted of a large amphitheatral cut in the 

northeast side of the ridge. Large trees were found in this cut and 

in the dumps. In 1896 a chestnut tree that measured 12 feet in circumference 3 feet above the ground was still standing in the clump.

On the west slope of the ridge at the southwest end of the works 

there is a shaft about 15 feet deep, and there is another of the same 

depth 23 feet to the northeast. Mica was found in both shafts, but 

the ground between them was not worked out. A 40-foot shaft, was 

sunk 71 feet northeast of the shaft last mentioned, but it did not find 

much mica. A shaft was sunk to a depth of more than 60 feet on 

the summit of the ridge. About 72 feet northeast of the shaft on 

the summit of the ridge, in an open cut, is the Gooseneck shaft, sunk 

by Colonel Irby to a depth of about 100 feet. About 50 feet farther 

northeast another shaft, called the Gooseneck No. 2, also about 

100 feet deep, was carried from the bottom of the amphitheatral 

cut. The vein was not thoroughly worked out southwest of the 

Gooseneck shaft, but between this and Gooseneck No. 2 most of the 

mica was stoped out. The Clarissa or Engine shaft is 133 feet northeast of the Gooseneck shaft No. 2. It was worked to a depth of 

312 feet. From the bottom of this shaft the work slopes up toward 

the Gooseneck No. 2 on the southwest and to the pump shaft in the 

Spread Eagle mine on the northeast. This was the limit of the 

Clarissa mine, the property adjoining it on the northeast being 

known as the Spread Eagle mine.

The Spread Eagle shaft is 35 feet east of the pump shaft. It 

was nearly as deep as the Clarissa shaft, and was used as the engine 

shaft for the Spread Eagle mine. Another shaft (Spread Eagle
XOKTH CAROLINA. 247

No. 2) was sunk 23 feet northeast of shaft No. 1, but not as deep. 

Still another shaft, 20 feet deep, was .used to pump the surface water 

from the Spread Eagle mine. The ground was largely worked out 

between the Spread Eagle No. 2, the Spread Eagle No. 1, and the 

Clarissa shafts. The workings sloped southwest from the bottom of 

ihe Spread Eagle No. 2 to the bottom of the Clarissa shaft.

The abstract from Westphalen's report follows:

Three shoots or chimneys of mica were worked within a space of 

150 feet northeast and southwest. These were called the Spread 

Eagle, Briny Deep, and Gooseneck. All were sunk to considerable 

depths by different persons, the Briny Deep being carried down 

 175 feet by Mr. Westphalen and opened by drifts and stopes. In 

this working the stopes were worked out by 3-foot benches, and in 

some of the larger stopes there were as many as 10 of these benches, 

one above the other. A large force of men worked at the mine during 

the day and a small force at night. Blasting was done twice a day. 

Water was hoisted in 50-gallon oil barrels at the rate of one barrel 

every 15 minutes. Other parties carried on mining by less systematic 

methods. Waste rock was allowed to accumulate or was dumped into 

older workings, which made them difficult to reopen.

The vein was inclosed in hard, firm walls below the zone of surface 

weathering and had a high to vertical dip. Its thickness was variable, ranging from a few feet to 10 feet, but as the vein bulged or 

pinched in places it averaged nearly 8 feet. The bulges were so rich 

in fine crystals of mica that it was difficult to drill without injuring 

the crystals'.

A study of the present surface indications shows that the country 

rock is hornblende gneiss interbedded with muscovite-biotite schist 

and gneiss. The mica schist and gneiss form the wall rock of the 

pegmatite. The pegmatite strikes about northeast and is approximately conformable with the gneiss. Potash feldspar, quartz, small 

mica, and opaque red garnets were observed in the dump. The mica 

has a fine clear rum color and good flat cleavage.

CLOTJDLAND MINE.

The Cloudland mine is 3£ miles S. 70° E. of Bakersville. in a mountain spur in a cove on the south side of a small tributary of Cane 

Creek. It received the name " Cloudland " because the Cloudland 

Hotel on the summit =of Eoan Mountain could be clearly seen from 

the mine and because the large white dump of the mine was so plainly 

visible from the hotel.

According to information given to J. A. Holmes by Thomas Green, 

in 1896, the deposit was discovered by Thomas Green about 1870 

while digging ginseng. Mica was found in a large rock, which was
248 MICA DEPOSITS OF THE UNITED STATES.

either a block fallen from the "vein" or one still attached to the 

" vein." The surface of this rock contained many crystals of mica, 

one of which, 8 by 24 inches across, was sold for $67. It would have 

brought $250 if it had not been exposed to the weather. This deposit 

paid a few men $4,000 in two months, after which it was worked by 

Abernathey & Rorison and later by Heap & Clapp. Colonel Irby estimates that the mine yielded mica worth about $100,000 up to 1896. 

It is now owned by Mrs. Ella Clapp Thompson, of Washington, D. C., 

and Mrs. V. P. Cibotti, of Philadelphia, Pa.

The mine is in a steep mountain side at an elevation of nearly 4,000 

feet above sea level or 1,000 feet above the valley two-thirds of a 

mile to the north. The entrance to the mine consists of a large open 

cut, which extends more than 100 feet back into the mountain side 

in a S. 70° W. direction. The cut, which is about 75 feet deep at its 

southwest end, passes into a stope (open to the surface through part 

of its course) and extends back into the mountain side in a sinuous 

course extending about S. 35° W. The open cut is 20 to 35 feet wide 

but has been partly filled by the blasting down and caving of the 

side along the hanging-wall. A large dump that stands about 100 

feet high and is probably 50 feet thick near the top has been built 

out on the mountain side. The stopes were closed by fallen rock 

when the mine was examined, and the notes on the underground 

workings are taken from a report by B. B. Westphalen, the former 

mine superintendent. The open cut is filled to a depth of 10 to 15 

feet with large blocks of wall rock and pegmatite. The stope was 

carried back for some distance to the southwest and was worked 

to a depth of 200 feet.

The country rock is muscovite-biotite schist and gneiss, which 

strikes northeast and has a variable southeast dip. The pegmatite 

is approximately conformable with the inclosing schist. The hanging wall in the open cut has a rolling dip, which ranges from 75° 

to 25° SE. and averages about 60°. The pegmatite cuts the schist 

where the wall has a low dip and is conformable where it has a high 

dip. Westphalen states that the dip in the deep stope was about 

75°. The pegmatite was about 40 feet thick in the deep stope, 20 

feet thick in the open cut, and pinched to 6 feet at the surface above 

the stope, at the southwest end of the open cut. Little pegmatite was 

exposed in place at the time of the examination. The material seen 

on the dumps contains quartz, mica, small quantities of bluish-green 

apatite and pinkish-red garnets, and a plagioclase feldspar that is 

nearly albite. The mica has a clear rum color and flat cleavage. 

The mine yielded a large output of mica of fine quality, which was 

taken from both the open cut and the deep stope. The " vein " 

for about 20 feet between these two workings contained little mica.
NORTH CAROLINA. 249 

RANDALL MINE.

The Randall mine is about 3 miles south of Bakersville. It was 

not visited by the writer. The information given below is taken 

from notes made by J. A. Holmes in 1896. The mine was opened by 

Peter Grindstaff and Dave Glenn about 1875 and worked successfully 

for about three years. It then changed hands, but the operations 

since 1878 have not been profitable. Four shafts were sunk to depths 

of 20 to 100 feet within a distance of about 160 feet in a line running 

northeastward. The "vein" between three of these shafts is said 

to be largely stoped out for a distance of about 75 feet to a depth of 

nearly 50 feet. The " vein " could be reached by a tufinel from the 

hillside at a level to permit drainage and mining. A good deposit 

of mica about 6 feet thick is reported to have been left in the bottom 

of the mine.

BUCHANNAN MINE.

The Buchannan mine is on the south slope of a small mountain 1-J 

miles N. 25° W. of Ledger. According to information furnished to 

J. A. Holmes by Bailey Bros, and Arthur Thompson it was opened 

about 1875 by William Buchannan, who removed mica worth about 

$1,500 in two months. Later the mine was operated by Colonel Irby 

and Jim Davis, and again by Arthur Thompson and West Bailey; 

There are two or more " veins " and on one of them pits were made 

by aborigines. At one place a tunnel was cut in the altered feldspar 

of the pegmatite for 15 feet alongside a quartz vein. Stone implements used by the prehistoric miners have been found around these 

old works, and fragments of^them were still to be seen at the mine 

when it was visited in 1904. The work by white men has been done 

principally on " veins " east of that worked by the aborigines. One 

of these deposits, probably another "vein," was worked intermittently by a tunnel in 1904, but the tunnel was locked and the mine 

was idle at the time of the visit. Another ledge of pegmatite crops 

out farther east and has been opened by several pits, an open cut, and 

a small tunnel.

The country rock is mica gneiss, which strikes about N. 25° E. 

and dips about 70° E. The bodies of pegmatite appear to be conformable with the inclosing gneiss. They contain streaks or ledges 

of massive quartz parallel with their walls. The mica is of good 

quality and is reported to be plentiful in places. Large crystals of 

green beryl are found occasionally, though none are of gem quality. 

Uranium minerals, pitchblende and its alteration products, are reported to have been found in some of the openings. Apatite and 

monazite are also reported to be associated minerals.
250 MICA DEPOSITS OF THE UNITED STATES.

SINK HOLE MINE.

The Sink Hole mine is near Bandana. It is one of the old mines 

of Mitchell County and was first worked by the aborigines. According to information given to J. A. Holmes in 1896 by Thomas 

Grindstaff and William Roberson the nature of these ancient workings was mistaken by General Clingman and a shaft was-sunk near 

them in search of silver in 18G8. Good mica was encountered but 

thrown on the dump, Avhere it was seen later by E. B. Clapp. Clapp 

recognized its value and soon commenced to work for mica in partnership with J. G. Heap.

A dozen or more shafts, some of them 150 feet deep, have been 

sunk by the persons working this mine, who have also done considerable drifting and stoping. Among the veins encountered were 

the Sink Hole " vein," the Silvers " vein," and the Rorison " vein." 

The underground work on these veins is said to amount to 2,000 to 

3,000 feet. The ancient workings are said to have been extensive 

and to have included small tunnels and shafts where the formations 

were soft. Large dumps were thrown out on the surface. When 

visited by the writer in 1906 the mine was being tested by William 

A. Robinson. It was opened in three places, one of which was an 

ancient stope about 18 inches wide and was in places filled with 

rubbish. Decomposed pegmatite, poor in mica, had been left as one 

wall of the stope by the aborigines and mica gneiss as the other. 

The other prospect work was so directed as to get to places where it 

was thought the whole " vein " had not been removed.

The country rock is mica gneiss, but the relations between the 

gneiss and the pegmatite were not well exposed. At one place a 

wall of one of the bodies of pegmatite cuts across the bedding of 

the gneiss. Much of the feldspar of the pegmatite in the upper 

workings is kaolinized. Mica of good quality was obtained in large 

quantities.

6IBB8 GREEN MINE.

The Gibbs M. Green mine is three-quarters of a mile northeast of 

Boonford. In 1906 it was opened by three pits, a tunnel 50 feet 

long, a shaft 45 feet deep, and other test pits. The tunnel connects 

with one of the pits at a depth of about 18 feet. The country rock 

is mica gneiss that strikes N. 20° E. and dips 75° E. The pegmatite 

is conformable with the inclosing gneiss. The mica has a darkbrown to green color and part is specked. Mica is said to be plentiful in places and blocks a foot in diameter have been found.

FLAT ROCK MINE.

The Flat Rock mine is 1 mile N. 30° E. of Penland. According 

to information given to J. A. Holmes by Col. Irby the mine was
NORTH CAROLINA. 251

opened by John Wilson and Moses Young in 1872. It was operated 

later at different times by J. W. Gudger, Col. Irby, Green & Baker, 

J. E. Burleson, and Baker & Rorison. The workings extended to 

a depth of 150 feet. The mine was abandoned when the timbering 

Avas knocked out by blasting and it caved in. About $15,000 worth 

of mica is reported to have been obtained.

The Flat Rock mine has been idle for many years, but the dumps 

have been turned over for small sheet and punch mica and for 

uranium minerals. When the mine was visited, in 1904, the workings appeared about as shown in figure 71. They consist of four 

shafts and a tunnel, from which large quantities of "vein" matter 

were removed. When the workings caved in a pit about 75 feet 

long. 50 feet wide, and 10 to 18 feet deep was formed around three 

of the shafts, as shown in the sketch. The country rock exposed in 

the east and south walls of the pit is coarse granite or fine pegmatite.

Outcrop of 

quartz ledge

7/5.i 

D'tfmp:%sj!A $$-M

71. Plan of Flat Roctf'mica mine, 1 mile northeast of Penland, Mitchell County,

N. C.

At the north end of the pit there is an outcrop of a part of a quartz 

ledge, about 4 feet thick. Quartz is said to have been found in 

large streaks through the pegmatite in the mine and to have overlain the richest deposit of mica. Among the minerals associated 

with the mica at this mine were pitchblende and its alteration products, cyrtolite, thulite (pink zoisite) in white feldspar, and garnet. 

The mica is of excellent quality and is said to have been found in 

sheets of large size.

During 1905 and 1906 J. E. Burleson sank a new shaft on a 

mica " vein" about 100 yards north of the old mine. This shaft 

was said to be nearly 100 feet deep, and drifts were run to the northeast and southwest from its bottom. According to Mr. Burleson 

two streaks of mica were encountered. The mica of the upper one 

had a greenish cast and A structure; that of the lower one contained 

flat, colorless mica.
252 MICA DEPOSITS OF THE UNITED STATES.

HIKES OF OAEOLINA MINERAL 00.

Some of the old mica deposits near Penland have been worked 

during the last few years for feldspar and mica by the Carolina 

Mineral Co. One of these is the old Deer Park mine No. 3, about 

one-third of a mile northeast of Penland, in a horseshoe bend of 

North Toe River. Another is on the opposite side of the river, west 

of Deer Park mine No. 3. The company has a water-power plant at 

Penland that furnishes power for punching and trimming machines, 

for running an air compressor to supply compressed air for drills' 

in the mine workings, and for operating hoisting engines for der- 

, , ricks. Nearly a

mile of piping has 

been used to carry 

compressed air 

to the openings. 

Several hundred 

yards of mine 

track and a spur 

that bridges the 

river connect the 

workings with the 

Carolina, Clinchfield & Ohio Bailway. A platform 

and chute at the 

end of the spur 

are used to load 

the feldspar directly into freight 

cars on a siding. 

Plate XXII is a 

south of west view of the mine, showing the railroad siding across the 

river. A large open cut is shown at 4 in the sketch forming figure 72. 

The country rock at these mines is highly schistose mica gneiss 

belonging to the Carolina gneiss, into which has been intruded many 

bodies of pegmatite, the largest more than 50 feet thick. Streaks 

and horses of the gneiss are included in the pegmatite and in some 

places are so large that they form the wall rock in the mine openings. The general strike of the gneiss in this region is east of north, 

but great variations occur in the neighborhood of the mine, where 

the strike is nearly east and west. The rock formations have decayed deeply on remnants of old peneplains that stand from 200 

to 250 feet above the river, as shown in the kaolin workings of the 

Harris Clay Co., one-third of a mile north of the mines. Erosion

FIGURE 72. Sketch showing position of workings and part of 

geology at feldspar-mica mine of Carolina Mineral Co., Penland, Mitchell County, N. C. For explanation of the numbers see text.
NORTH CAROLINA. 253

along the river has removed most of this mantle of decomposed 

pegmatite and gneiss in the feldspar-mica mines 100 to 200 feet 

lower, and fairly fresh rock is encountered near the surface.

The rough sketch map forming figure 72 shows the location of 

the different workings on the south side of North Toe River, which 

are described below. The workings described are numbered to correspond with the numbers used in the sketch map.

1. An open cut passing into a stope nearly 100 feet deep at an inclination of 

40° S. and a tunnel run from the hillside 125 feet to the east. The open cut 

Is about 25 feet square but becomes smaller in the stope below. A long trenchlike cut was made up the hillside north of the mouth of the tunnel on a small, 

rich streak of mica. These workings are in a large deposit of pegmatite, as 

shown in figure 72. The pegmatite is mostly conformable with the schistosity 

of the gneiss, but at some places cuts across it. A few streaks of mica schist 

are included in the pegmatite, about parallel with the walls.

The pegmatite is coarse grained and contains potash feldspar crystals 1 foot 

to 2 feet thick, masses of granular smoky quartz, and mica in crystals of different sizes. A little uranium mineral was found in this working, and a few 

stains of autunite or similar alteration products of pitchblende were seen on 

the dump. The mica was irregularly distributed through the mass of the pegmatite in the main workings and in a streak or vein 1 foot to 2 feet thick that 

cut across the mass of the pegmatite with a vertical dip in the long trench.

2. A large open stope more than 50 feet deep on an incline of about 40° S. 

The pegmatite is coarse-grained and thick, about 301 feet being worked under 

the hanging wall. Potash feldspar occurs in large, pure crystals and smoky 

quartz in granular masses a foot or two thick. Mica occurs in a streak 3 to 4 

feet thick inclosed in the feldspar and about parallel with the walls. The crystals are plentiful in parts of the mica streak and some of them measure more 

than 12 inches across. Good specimens of pitchblende and its associated alteration products were found in this working.

3. An open cut about 75 feet across and 20 to 400 feet deep; a 40-foot tunnel runs from it to the west. Highly schistose mica gneiss, which strikes about 

east and dips 60° S. forms the south wall. The body of pegmatite is large, and 

a thickness of more than 30 feet was worked, chiefly for feldspar. A little good 

mica is scattered irregularly through the rock. The feldspar was partly kaolinized near the surface but was fresh and of good quality below a depth of 15 

feet.

4. An open cut about 150 feet long, 10 to 30 feet wide, and 10 to 40 feet deep, 

opened chiefly for feldspar, which occurred in a rich streak, 10 to 25 feet thick, 

having a northeast strike and southeast dip. Some sheet mica and masses 

of solid mica composed of bunches of sjuall crystals were also found. Plate 

XXIII, A, shows working No. 2 in the foreground, No. 3 in the center, and the 

dump from these and from working No. 4 on the extreme right. This view was 

taken S. 80° W. from a point across the river.

Other workings have been made for feldspar and mica across 

North Toe River southwest of the open cut at 4. These consisted of 

a few hundred feet of tunnels, some stopes, and a little open-cut work 

in the bank above the railroad. The feldspar was loaded by a chuto 

into freight cars on a side track below. These workings were not in 

operation at the time the mine was visited in November, 1914. The
254 MICA DEPOSITS OF THE UNITED STATES.

 workings were in a large deposit of pegmatite, which was partly decomposed near the surface. Streaks of mica schist or gneiss were inclosed in the pegmatite, but the true walls were not exposed.

The mica from all the workings is similar. Some of the crystals 

are more than a foot in diameter. A rather large proportion of it 

is wedge-shaped or A mica, but some good sheet mica is also obtained. 

The mica is clear and has a rather dark smoky greenish-brown color 

in sheets one-sixteenth of an inch thick. Where free of A lines it 

splits smooth and flat. Pretty flattened clear cherry-red garnets 

have been found in some of the sheets of mica, chiefly those that have 

the A structure somewhat developed. These garnets range from 

the thickness of paper to more than one-sixteenth of an inch and 

reach a quarter of an inch in diameter. The angles between the crystal faces around the edges are plainly evident.

The feldspar forms the most valuable product of these mines, but 

in places the deposits of mica have also been valuable. The feldspar 

is a light-gray potash variety, chiefly microline, and occurs in fairly 

large pure masses that can be cobbed over easily. It is shipped to 

Trenton, N. J., and East Liverpool, Ohio, for use in making pottery.

MINES OF HARRIS CLAY CO.

The Harris Clay Co. was operating two mines in the Spruce Pine 

region at the time the place was visited in 1914. One of these was on 

the east side of Beaver Creek valley, 1-| miles N. 30° E. of Spruce 

Pine, and the other was one-third.to one-half a mile northeast of 

Penland. Both of these deposits have proved large and have been 

worked over areas of several acres. Similar modes of operation 

have been employed in both mines. First the overburden of discolored surface clays is removed by scraping, digging, and carting, 

and the underlying kaolin is removed in open cuts and circular shafts 

lined with wooden blocks. The kaolin as excavated is thrown into 

sluices and carried down to cleaning mills, where it is washed, floated, 

settled, molded, dried and otherwise prepared for shipment to pottery manufacturers. The circular shafts are carried to depths of 50 

to 90 feet, according to the depths at which the feldspar of the 

original pegmatite has been altered to kaolin. The shafts are sunk 

from the bottom of the cuts where open work is no longer feasible. 

The shafts started at higher elevations on the hillsides are in general 

deeper than those started at lower levels.

The deposit on Beaver Creek lies between 2,700 and 2,800 feet above 

sea level, and that near Penland between 2,600 and 2,700 feet, extending from the remnants of bench lands at a distance from the 

creek and river down the hillslopes. At each deposit both the original pegmatite and the inclosing mica gneiss country rock have been
NORTH CAROLINA. 255

deeply weathered, probably during a long period in which there was 

relatively little uplift and but slight erosion. During this time 

broad, flat valleys were developed and the products of weathering 

remained in place in them. A later uplift of the region gave the 

streams new cutting power, and the present valleys were cut below 

the bottoms of the original broad valleys, scattered remnants of 

which have been left along the sides of the present valleys.

The Beaver Creek and Penland kaolin deposits are the remnants of 

large deposits of pegmatite that were extensively decomposed during 

a period of slow erosion. The feldspar was altered to kaolin by the 

dissolving out of the alkalies and hydration. The less easily altered 

minerals, quartz and mica, remained as they were, being now embedded in a kaolin matrix instead of feldspar. The original pegmatite occurred in large beds or irregular deposits, which were separated by or included streaks of mica gneiss that now form barren 

places in the kaolin deposits.

The effects of the long and steady weathering on the pegmatite 

are shown in strong contrast by the large deposits of kaolin in the 

Penland mine and the hard, fresh pegmatite encountered near the 

surf ace in the feldspar and mica mines of the Carolina Mineral Co., 

just across North Toe Elver to the south and 100 to 200 feet lower. 

The kaolin workings are seen on the summit of the hill to the right 

and the dump of the Carolina Mineral Co. mine about 15 feet above 

the river level to the left in Plate XXIII, in which A and B form a 

panoramic view.

At the Beaver Creek workings a large quantity of small mica has 

been removed during the mining for kaolin and has Been separated 

from the associated quartz and other minerals in a washing plant 

by the English Mica Co., of Spruce Pine, and then ground as scrap 

mica. A small quantity of larger crystals of mica, suitable for sheet 

or punching, has also been found in the mining for kaolin.

EDGAR BROS. KAOLIN AND MICA MIKE.

A deposit of kaolin was opened in 1906 by the Edgar Bros., 2£ 

miles north of Penland, in the forks of Bear Creek. The washing 

plant was on the railroad along North Toe River, a quarter of a mile 

above Penland, at the place where the Harris Clay Co.'s washing 

plant now stands. The mine was operated for kaolin, and considerable small-sheet and scrap mica was obtained as a by-product. 

Basket pits about 20 feet in diameter, lined with cribwork, were 

sunk in the usual manner in the body of the kaolin deposit The 

material from the pit was dumped into a washing bin and washed 

over screens with 1-inch openings by a jet of water. The mica and 

waste were shoveled off the screen at intervals when the kaolin was
256 MICA DEPOSITS OF THE UNITED STATES.

washed from it, and the mica was sorted later. The kaolin was carried through about 800 feet of wooden trough to a revolving-cylinder 

disintegrator and thence to a settling bin, where the grit and coarse 

material were deposited. The fines were washed a second time and 

sent through another 800 feet of board sluice, which had a more 

gentle slope than the first 800 feet. The settlings were shoveled out 

of this as needed. From the sluice the fine kaolin was carried suspended in water through 3 miles of 5-inch pipe to the drying plant, 

where it was run into settling vats. The water is decanted off and 

the kaolin mush is pressed into disks in molds and dried.

The body of decomposed pegmatite that is suitable for kaolin is 

large and is reported to have been proved by boring 200 yards 

northeast of the place first opened. It is in hornblende gneiss 

country rock, also much decomposed. The pegmatite is, in part at 

least, the typical variety, and has quartz and mica scattered

through it.

DEAKE HIKE

The Deake mine is about a mile northwest of Spruce Pine, on the 

south side of North Toe River, about 100 feet above the river. The 

workings are not now open for examination, and all that can be seen 

are the remains of old cuts, tunnels, and a large dump. According 

to information furnished by Colonel Irby, the mine was discovered 

by Lewis Cook and developed by J. C. Deake. It was afterwards 

operated at different times by different persons and is estimated to 

have yielded mica worth from $60,000 to $75,000. The "vein," 

which is reported to be nearly flat, crops out on the river bank. It 

has been worked both by tunnels from the hillside and by shafts from 

the surface. Mica of fine quality was obtained as well as good specimens of uranium minerals.

BILL WILLIS MINE.

The Bill Willis mine is about a mile northwest of Spruce Pine, on 

the south side of North Toe River, about 200 yards west of the Deake 

mine. It was reopened in 1906 after remaining idle for a number of 

years. A new crosscut tunnel was driven in to cut a 25-foot incline 

from an old open cut. The pegmatite has been opened by a cut run 

eastward for about 60 feet along the hillside. The mica from the 

east end of the workings has a dark-green color and is partly A and 

partly hair-lined. Near the west end of the workings the mica has 

a rum color and is of good quality. The pegmatite is well exposed 

at the west end and is massive. The crystallization is very coarse, 

and rough crystals of orthoclase feldspar 2 feet thick were seen in the 

walls. A large streak of quartz of smoky-blue color is exposed in 

the pegmatite, and the greater part of the mica is found near this.
NORTH CAROLINA. 257

Some of the sheets of mica have flattened garnets between the 

laminae.

WESTALL MINE.

The old Westall mine, owned at the time it was examined, in 1914, 

by Mrs. T. C. Turbyfill and Mrs. S. A. Dorsett, of Spruce Pine, is 1£ 

miles N. 70° W. of Spruce Pine. It was discovered by W. B. Westall 

and was opened in 1876 by Col. J. K. Irby, and it has been operated 

intermittently since by different persons. The workings consist of 

an open cut and a shaft run from its bottom to connect with stopes 

below. The stopes also connect with a tunnel run from the foot of 

the hill at a level about 60 feet lower. The full size of the stope 

 could not be determined because the roof had caved in. The mine 

was being worked in a small way in 1914 for both mica and feldspar.

The country rock is coarse mica gneiss and incloses beds of hornblende gneiss east of the mine. Near the mouth of the tunnel the 

gneiss is cut by coarse granite, which strikes east and dips 45° S. 

The body of pegmatite is large, at least 15 feet thick, and has been 

opened by a stope run N. 60° W. on a slope of 45° SW. The pegmatite occurs in crystals more than 2 feet thick, and a massive segregation of quartz encountered in the east side of the open cut is about 

10 feet thick. Part of the pegmatite is decomposed near the surface, 

but good fresh feldspar is obtained in the lower part of the mine. 

Some of the crystals of mica are more than a foot across, and one 

block is reported to have weighed 150 pounds. The mica is dark 

greenish brown. Many of the crystals have A lines but yield good 

sheet mica between these structures.

F. M. TOLLEY MIKE,

The F. M. Tolley mine is about a mile west of Spruce Pine. It was 

worked by a tunnel from the hillside und by shafts run on the vein. 

The country rock is partly decomposed mica gneiss. The body of 

pegmatite is large and the rock grades from coarse grained in the 

mica-bearing part to fine grained where it is exposed near one of the 

avails. It has been partly decomposed and crumbles away after mining. The mine is reported to have yielded considerable mica of 

good quality.

CHALK MOUNTAIN MINE.

The Chalk Mountain mine is about 2 miles southwest of Spruce 

Pine, on the west side of Chalk Mountain, near its summit. It has 

been opened by a tunnel run in along the strike of the pegmatite, 

two shafts, and several prospect pits and trenches. These openings 

fall within a space that extends about 100 yards N. 70° E., a direction which represents the strike of the pegmatite. The pegmatite
258 MICk DEPOSITS OF THE UNITED STATES.

is inclosed in mica gneiss in approximate conformity with its bedding 

and dips about 45° N. The workings are in such bad repair that 

little could be seen of the " vein." The dumps show1 that the formations encountered are fresh and little decomposed. Dark-green 

octohedrons of gahnite spinel were found in blocks of feldspar 

thrown on the dumps.

Z. T. McCHONE MINES.

The McChone mines are 1 mile S. 30° W. of Spruce Pine, nearly 

a mile east of Chalk Mountain on the same ridge. They include a 

mica mine, two aquamarine prospects, and a prospect yielding 

crystals of spodumene and amazon stone. The mica deposit has been 

worked intermittently; the other deposits have been opened only in 

a small way. From two of them crystals of beryl were obtained 

that would yield very small gems of aquamarine. Amazon stone or 

green microcline feldspar was found in these deposits and also in 

the deposit yielding spodumene. The amazon stone is semidecomposed at the surface, though it still retains its green color when 

partly kaolinized. Fragments of badly decomposed crystals of 

spodumene, 1 inch to 3 inches across, were seen on the dump of one 

of the prospects. A small part of the interior of these crystals was 

still unaltered. This fresh spodumene was transparent yellowish 

green, resembling in color the poorer grades of beryl. Chips as 

large as 2| by 5 by 7 millimeters were seen, perfectly transparent 

and free from flaws.

BLALOCK MINE.

The Blalock mine is about half a mile northwest of Spruce Pine, 

on the north side of Toe River valley. It was opened about 18T3 by 

McKazier & Campbell and worked for three years. Since 1876 a 

small amount of exploring work has been done at different times, but 

no regular operations have been undertaken. The workings have 

fallen in so badly that little could be seen of the formations. A 

quantity of decomposed fine pegmatite had been thrown on the 

dumps along with the kaolinized feldspar of the mica-bearing part 

of the " vein."

N W. W. WISEMAN MINE.

The W. W. Wiseman mine is 2 miles N. 25° E. of Spruce Pine, 

on the east side of Beaver Creek valley. According to Mr. Mart 

Wiseman it was opened by James Wiseman and John Pendley in 

1875. These men removed mica worth from $2,000 to $3,000 in 

one year's work. Later the mine was operated by Lum Blalock and 

Luke Lewis, and still later by other parties. About 1890 the mine 

was again operated, this time by the Southern Mica Co., and con-
NORTH CAROLINA. 259

siderable work was done. After a number of years of idleness it 

was reopened by the Carolina Mineral Co., and has been worked 

for feldspar and mica for several years.

The mine is in a steep ridge or spur that pitches westward into 

the valley of Beaver Creek. The old workings consisted of a shaft 

30 feet deep, a tunnel 40 feet long run from the shaft, and another^ 

tunnel about 100 feet to the north, now caved in. The 30-foot shaft 

and 40-rfoot tunnel have been mined away in the later workings. 

When the mine was first examined, in 1904, the workings of the Southern Mica Co. were still open. 

They consisted of a crosscut tunnel more than 200 

feet long driven into the 

" vein " and extensive stopes 

that reached 40 or 50 feet 

above it. In 1914 the workings had been greatly enlarged. The upstope on the 

" vein" had been raised to 

the surface, nearly 100 feet 

above, and extended farther 

east, forming a deep open 

cut or a large open stope 

more than 100 feet long and 

10 to 30 feet wide. Plate 

XXIV, A, is a view eastward across the deep stope 

from the bottom of the small 

open cut at the west end of 

the workings.

The country rock is highly 

schistose mica gneiss, which 

varies in dip and strike 

where it is cut by the tunnel. 

The body of pegmatite is at least 30 feet thick, and cuts across the 

gneiss and schist with an easterly strike and about a vertical dip. Several feet before the tunnel reached the " vein " it encountered coarse 

granite or fine-grained pegmatite, which grades into coarse pegmatite 

nearer the " vein." The coarse granite cuts the schistosity of the gneiss, 

which trends N. 15° W. and has a 25° W. dip along the contact. Figure 73 shows the position of the workings and the relations of the rock 

formations. Before the stope was opened to the surface the coarse 

crystallization of the pegmatite was clearly exhibited by the candle 

light reflected from the cleavage faces of trie crystals of potash feldSHOP

.. 

. dump:£:

Mica schist 

and gneiss

Strike and dip

Approximate scale 

o 100 Feet

FIGUBB 73. Plan, of W. W. Wisemau mine, on 

Beaver Creek, Mitchell County, N. C.
260 MICA DEPOSITS OF THE UNITED STATES.

spar exposed. Crystals 2 and 3 feet square had been cut through. 

This coarse crystallization occurs in a streak in the interior of the 

pegmatite. The large crystals of feldspar were most plentiful near 

the middle of the pegmatite, and the. mica lay in a shoot on the north 

side of it, pitching west. Practically all of the shoot has been mined 

out, but some mica is still found in other places. In the early days 

of mining one crystal of mica weighing about 2,000 pounds is reported to have been obtained from this mine. It is said six men were 

able to dance on this crystal at one time. The mica has a dark bottlegreen color and good flat cleavage. Some is partly specked.

The feldspar is chiefly of the pinkish potash variety but includes 

some white plagioclase. When the mine was last visited, in 1914, 

about 40 tons of feldspar was being shipped each week. Fine specimens of the uranium minerals (pitchblende, gummite, and uranophane), and of allanite, cyrtolite, and other rare-earth minerals have 

been found. Masses of samarskite weighing many pounds were 

mined during the early days, but they were broken up and lost before 

their nature was known.

Dip

FIGURE 74. Section In plane of pegmatite at Knob mica mine, Mitchell County, N. C.

KNOB MINE.

The Knob mica mine is a little more than 2 miles northeast of 

Spruce Pine. The pegmatite is inclosed in biotite gneiss or schist, 

with which it is roughly conformable. It strikes about N. 45° E. 

and dips about 40° SE. The pegmatite is coarsely crystallized next 

to the hanging wall and grades into fine-grained pegmatite or coarse 

granite on the lower side. The coarse pegmatite, called the " vein," 

which is the only part of the deposit mined, pinches and swells, ranging in thickness from 1 to 4 feet. The mine was first worked by 

open cuts on the outcrop and by shallow inclines. Later a drift was 

run about 150 feet from the outcrop lower down on the hillside, 

and parts of the "vein" were stoped out to the open cut above.
U. S. GEOLOGICAL SURVEY 

VIEW EASTWARD TOWARD WORKINGS OF CAROLINA MINERAL CO.'S MICA-FELD

COUNTY, N. C.
U. S. GEOLOGICAL SURVEY BULLETIN 7-10 I'T.ATK X.XIII

.4. VIEW WESTWARD TOWARD WORKINGS OF CAROLINA MINERAL CO.'S MICAFELDSPAR MINE, NEAR 1'ENLAND, MITCIIELL COUNTY, N. C.

B. VIEW NORTHWESTWARD TOWARD HARRIS WORKINGS OF HARRIS CLAY CO.'S 

KAOLIN MINE, NEAR PENLAND, MITCHELL COUNTY, N. C.
U. S. GEOLOGICAL SURVEY IH'LLKTIN ~M PLATE XXIV

A. VIEW EASTWARD ACROSS DEEP OPEN STOPE OF THE 

WISEMAN MICA MINE, CAROLINA MINERAL CO., ON 

BEAVER CREEK, MITCHELL COUNTY. N. C.

B. VIEW NORTIHVAIU) TOWAlll) WORK IMiH OF WILLIMON MICA MINE, 

GREENVILLE COUNTY, S. C.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XXV

A. VIEW SOUTHWARD FROM HARNKY PEAK, BLACK HILLS, S. DAK., SHOWING 

OUTCROPS ()! ' PEGYIATITir. (JIUNITE.

B. VIEW NORTHWARD TOWARD NEW YORK MICA MINE, NEAR CUSTER, S. DAK.
NORTH CAROLINA. 261

Figure 74, which is a section in the plane of the " vein," shows the 

nature of the work done at the time the mine was visited. The mica 

.is dark green, and some of it is abundantly specked with dendritic 

spots of magnetite. Large crystals are found. One weighing 165 

pounds and measuring roughly 12 by 20 by 30 inches was obtained 

in 1904. The mica was split and graded at the mine an'd shipped to 

manufacturers of electrical apparatus. B6th men and women were 

employed in this work.

SURVEY PBOSPECT.

The Survey prospect, owned by Capt. Isaac English, is about 100 

yards southeast of the Knob mica mine and a little more than 2 miles 

northeast of Spruce Pine. It consists of a pit about 10 feet deep, 

in which uranium minerals were reported to have been found, especially gummite, whicli was said to have occurred in balls at the end 

of black streaks through the " vein " rock. In 1904 two employees of 

the North Carolina Geological and Economic 'Survey spent two days 

on this prospect in search of uranium minerals.

The country rock is mica gneiss, and the " vein " consists of coarse 

pegmatite and the hanging wall of fine pegmatite or coarse granite, 

into which it grades. The vein strikes about northeast and dips 25° 

southeast. The feldspar of the pegmatite is orthoclase or microcline 

and occurs in fairly large, rough crystals. The quartz is nearly clear 

and has a smoky color. The greater part of the mica is A and 

wedge shaped, though mica suitable for punching was seen. Flattened crystals of garnet are numerous between the laminae of the 

crystals of mica and some have a beautiful color. Thulite, the pink 

variety of zoisite, is found in places in feldspar. Several slender 

black crystals of the thickness of a match and 6 to 10 inches long, 

probably allanite, penetrated the quartz and feldspar. At the ends 

of these there were bunches or balls of slightly yellow clay, which 

gave a test for uranium with the salt of phosphorus bead. No other 

uranium minerals were found. A small quantity of punch and smallsheet mica were obtained during this work.

N

RUTHERFORD COUNTY. 

ISINGLASS HILL MINE.

The Isinglass Hill mine is on the Southern Railway about 3£ miles 

north of Rutherfordton. Here a mass of pegmatite more than 30 

yards thick carries mica. The country rock is hornblende gneiss, 

much folded and contorted, and the pegmatite is roughly conformable 

with it. The strike is east of north, and the dip in general is nearly 

vertical. The pegmatite near the mica workings is several yards

111375 23 18
262 MICA DEPOSITS OF THE UNITED STATES.

thick, but in a railroad cut 200 yards to the north it shows only as 

small streaks, probably stringers from the main mass. The pegmatite has been traced southward for more than 200 yards by prospect 

shafts, but its thickness at these shafts is not known. Mica was 

found most plentifully where the open cuts are shown in figure 75.

At these places most of it is associated 

with a streak of massive quartz. The 

depth to which the workings had been 

carried could not be ascertained, for they 

had caved in badly, as the rock was soft. 

The mica is in large part badly specked 

with magnetic iron. The large quantity 

of sheets 2 to 5 inches in diameter left 

on the dump indicates that the mica 

must have been plentiful, though much 

of this waste was either A or wedge 

mica.

Since the operations for mica were 

suspended the deposit has been examined 

to determine its value as a kaolin mine, 

and in this examination some of the tunnels on the east and shafts to the south 

were made. Good kaolin was found in 

some of the openings, but its extent had 

not been adequately proved at the time 

the place Avas visited. The following 

analysis of the kaolin, made by T. W. 

Smith, commercial chemist, Indianapolis, Ind., was furnished by 

Mr. Olive, owner of the mine:

Anlysis of kaolin from Isinglass Hill mine, N. C.

SiO,_________________________________ 44.12

Al,03 _________________________________ 39. 50

CaO_________________________________ . 08

MgO ______________________ _______ Trace.

FeO________________________________ . 08

Alkalies____________________ __ . 81

Ignition_______________________________ 14. 53

o

nel with dump

bOOFeet

FIGURE 75. Plan of Isinglass Hill 

mica mine, Rutherford County, 

N. C., showing probable shape 

of the pegmatite.

99.12

Rational analysis:

Clay substance__ 95. 59 

Quartz _______________.____ ____ 3. 39 

Feldspar ____________________________ 1.02

100.00
2TORTH CAROLINA. 263

The kaolinized portion of the pegmatite yielded 42 per cent of 

kaolin having a refractory value of 1,730° C. when sampled and 

washed by A. S. Watts.69

Mica prospects have been opened at several other places in Rutherford County. V. A. Smith, of Golden, N. C., opened one on the. 

top of Cherry Mountain, about 8 miles north of Bostic, and reported 

that two prospects were being tested near Union Mills in the spring 

of 191C. Other deposits have been prospected on the Alien and J. 

Odom properties between Gilkey and Union Mills, on the Joseph 

Groves property, 1| miles northeast of Gilkey, on the W. T. Wilkins 

property, 3£ miles west of Rutherfordton, and on the W. H. Marvill 

property. 4 miles northeast of Rutherfordton. The Alien mine is 

an old one and the workings, which consist of several shafts and 

pits, were badly caved in when seen in 1906. The country rock is 

mica gneiss, in part granitic. Blocks of massive quartz on the 

dumps show that one or more streaks of quartz were encountered in 

the workings.

STOKES COUNTY. 

JOE HAWKIN3 MINE.

The deposit of mica at the Hawkins mine Av'as first worked about 

1890 by people living in the county and was again worked in 1903 

by the Empire Mica Co., of New York. It is about 2£ miles southwest of Sandy Ridge, in the northeastern part of Stokes County. 

The mica occurs in an irregular body of massive pegmatite, in which 

feldspar and quartz form large separate masses. The body exposed in the workings ranges in thickness from 6 to 12 feet and is 

approximately conformable to the inclosing mica gneiss country 

rock, which strikes a little north of east and dips about 35° 1ST . Much of the quartz of the pegmatite occurs in bands or sheets, 

from a few inches to about 2 feet thick, lying parallel with the 

strike of the pegmatite. But little mica had been left in the " vein " 

from the last work, and much of that seen was of the wedge and 

A variety, but included good mica between the A structure lines. 

Some of this wedge and distorted mica contained rough garnets, 

either in crystals or flattened between the laminae. The workings 

consist of two open cuts, an incline run on the pegmatite from one 

cut, three shafts 20 to 30 feet deep, and connecting tunnels. In 

all there is nearly 150 feet of tunnels and incline.

HOLE MINE.

The Hole mica mine is on the ridge between Dan River and Big 

Creek, near the mouth of the creek and near Tulip post office. There

69 Mining and treatment of feldspar and kaolin: U. S. Bureau of Mines Bull. 53, 

p. 148, 1913.
264 MICA DEPOSITS OF THE UNITED STATES.

are two separate bodies of mica-bearing pegmatite at this mine, 

which are opened at points about a third of a mile apart in an 

easterly direction. The principal deposit consists of a large body 

of pegmatite more than 20 feet thick, which strikes nearly east and 

dips 30° N. This deposit, as exposed in the open work on the 

outcrop and small inclines, is composed of three bands or veins of 

massive quartz, 4 to 6 feet thick, and of two intervening beds of 

feldspar, 4 to 7 feet thick. It is said that another band of feldspar 

was found beneath the lower vein of quartz, but this was covered 

with rubbish and could not be examined. The bands or veins of 

quartz and feldspar are parallel with the body of pegmatite and 

dip with it to the north. The feldspar has been considerably kaolinized and has been removed from the two veins exposed in inclines

Inclines on feldspathic 

portions of pegmatite

FIGURE 76. Ideal cross section at Hole mica mine, Stokes County, N. C.

10 and 20 feet deep. The large streaks of feldspar contained small 

masses and streaks of quartz, 1 inch to 10 inches thick. Figure 76 

is an ideal cross section of the pegmatite, which can be traced for 

several yards along the outcrop by blocks of massive white quartz. 

Mica occurs through the masses of feldspar and along the contact 

with the streaks of quartz. The mica is partly of the A variety 

and has a brownish or smoky color. A 20-pound block of such mica 

was seen in the face of one of the veins.

At the other outcrop a few small open cuts and an incline 20 feet 

deep have proved the pegmatite for about 200 feet along a steep 

hillside. The course of the pegmatite here is conformable with the 

schistosity of the mica gneiss country rock and is several feet thick. 

The dip and strike are very much the same as at the deposit first
NORTH CAROLINA. 265

described. The feldspar of the pegmatite has not been kaolinized, however, and the formation is fairly hard. Only small blocks 

of mica were seen in the hard rock, and this mica was of clear darkgreen color, considerably ruled.

STEELE MICA MINE.

The Steele mica mine is about 2 miles southwest of Sandy Ridge 

and was operated by the Southern Mica Co. at about the same time 

as the Hawkins mine. A shop for cutting and trimming mica was 

set up and preparations were made for extensive operations. The 

work consisted of three pits, a small shaft, and probably 30 feet of 

tunnel. It was not possible to determine the relations of the pegmatite to the country rock, which is mica schist or gneiss that strikes 

about N. 55° E. and dips 45° NW. The body of pegmatite is apparently large, or it consists of more than one mass. Much of the 

mica seen on the dumps was of the A variety, though some was in 

sheets 8 to 10 inches across and would yield good mica between the 

A markings.

RICHARD FOREST PROSPECT.

The Richard Forest prospect is on the north end of Brown Mountain. Here a 15-foot incline was sunk on the dip of the pegmatite. 

The inclosing rock is mica schist or gneiss, which strikes N. 50° E. 

and dips 35° NW. The pegmatite contains quartz "veins" parallel 

with its walls and the mica is found between them and the walls. 

Part of the mica seen on the dump was of the A sort, though some 

was of fair quality. Sheets more than one thirty-second of an inch 

thick had a green color.

A shaft was sunk on a mica " vein " at the north end of the top of 

Brown Mountain, on the land of William Martin. Much small-sheet 

mica was seen around the old shaft and there were indications of 

mica along the surface for some distance. The country rock is 

garnetiferous mica schist. Mica prospects are also reported to occur 

on the top of Brown Mountain on the properties of Samuel Simmons, 

William Hills, Thomas Bundurn, and William Nunn.

TRANSYLVANIA COUNTY. 

BEE TREE FORK MINE.

The Bee Tree Fork mine is on a hillside opposite the mouth of 

Bee Tree Fork, on the headwaters of French Broad River. It was 

opened years ago by Tarry McCall and after lying idle a long while 

was reopened in 1905 by C. H. Wolford. The workings consist of 

an open cut 50 feet long and 35 feet deep at its deeper end, in 

the hillside. The cut is but little wider than the " vein." The coun-
266 MICA DEPOSITS OF THE UNITED STATES.

try rock is mica gneiss, which strikes about northeast and dips 45 ^ 

NW. The " vein " cuts across the country rock in a sinuous course 

and has an irregular easterly strike and a dip ranging from 45° 

to 80° N. The pegmatite ranges in thickness from 2 to 8 feet and 

is composed principally of quartz, though some feldspar, mica, 

pyrite, and pyrrhotite are scattered through it. The mica has a 

clear rum color and is of good quality.

CHESTNUT RIDGE MINE.

The Chestnut Ridge mine is at the headwaters of French Broad 

River, 2£ miles S. 55° E. of Tennessee Bald. The work consists of 

a tunnel run on a small body of pegmatite and two open cuts made 

on another larger body. The country rock is mica gneiss. The 

pegmatite exposed in the open cuts is in places as much as 10 feet 

thick. The mica is of good quality and has a clear rum color, though 

some of it is ruled into strips. Biotite is associated with the muscovite.

REED MINE.

The Reed mine is 1 mile N. 60° E. of Montvale and 2£ miles S. 

20° E. of Sapphire. It is owned by Dr. Robert Grimshawe, of Montvale. The mine has been worked by several tunnels run at different 

levels, the greater part of them now fallen in. One 30-foot tunnel 

was driven in on a 5-foot " vein " which had a north strike and a 

dip of 30° W. This body of pegmatite is irregularly conformable 

with the inclosing mica gneiss country rock. It has a 2^-f oot quartz 

streak in the middle and feldspar on each side. About 75 feet 

to the north, on the opposite side of a small valley, the same " vein " 

has been worked by two levels, between which the " vein " has been 

stoped out. One of these levels was driven back about 100 feet. The 

pegmatite in this tunnel had a strike of about N. 20° E. and a dip 

of 35° NW. At the end of the tunnel it had pinched down to a 

thickness of about 18 inches and contained small scattered lenses 

of quartz. The mica from the Reed mine is dark and is in part 

specked with magnetite.

BIG JTJMBO MINE.

The Big Jumbo mine is in the gap on the south side of Sassafras 

Mountain, about 1£ miles west by north of Montvale. The mine has 

not been worked for several years and now belongs to Dr. Robert 

Grimshawe, of Montvale. Two open cuts have been made, one in 

the gap and the other about 100 yards N. 25° E. of it, at the foot of 

the steep grade to the mountain top. The country rock is mica 

gneiss, which contains a few small streaks of hornblende gneiss in 

the vicinity of the mine. A ledge of pegmatite about 10 feet thick
NORTH CAROLINA. 267

was encountered in the cut in the gap. This ledge is apparently conformable with the inclosing mica gneiss, which strikes about N. 20° 

E. and dips 30° SE. A considerable quantity of mica was found, 

though only the inferior material had been left on the dump. This 

mica has a smoky brown color, and some of it contains fine black 

specks of magnetite between the sheets. Part of it has the A and 

tangled-sheet structure. Little could be seen of the formation at 

the other opening.

LITTLE JUMBO HIKE.

The Little Jumbo mine is 1£ miles N. 65° W. of Montvale. The 

mine was worked along the bank of a branch' by three or more tunnels. The country rock is mica gneiss, which strikes N. 15° E. and 

dips east. The pegmatite is conformable with the strike of the gneiss 

and possibly with the dip also. It contains streaks and masses 

of quartz at least 3 feet thick.

MORNING STAR MINE.

The Morning Star mine, owned by Dr. Robert Grimshawe, is threequarters of a mile west by north of Montvale and 2f miles 

S. 20° W. of Sapphire. It was worked by C. Grimshawe between 

1880 and 1884, during which time 8,000 pounds of cut mica was 

mined. The workings consist of several tunnels, now nearly all 

caved in. The country rock is mica gneiss, more or less crumpled. 

The pegmatite, which is approximately conformable with the gneiss, 

strikes from north to N. 25° E. and dips 25° E. It is from 1 foot 

to 3 feet thick and contains many streaks of quartz. Where seen the 

quartz streaks were from 1 inch to 12 inches thick and were at least 

equal in volume to the pegmatite. The mine is reported to have 

yielded large blocks of dark-brown mica.

TALLOW FACE MINE.

The Tallow Face mine is three-quarters of a mile east of Montvale 

and 2f miles S. 10° E. of Sapphire. It has been opened by a 70-foot 

tunnel or drift on the " vein " and a 60-foot shaft, sunk to cut the 

pegmatite on the dip but not connected with the tunnel. The country 

rock is pegmatized mica gneiss. The pegmatite is about 8 feet thick, 

strikes N. 25° E., and dips 25° NW. The pegmatite near the mouth 

of the tunnel carries a 3-foot streak or vein of quartz, which is split 

by a streak of feldspar. A short distance within the tunnel the 

streak of quartz is less prominent and the pegmatite has more nearly 

the texture of typical coarse granite.

W. J. NICKELSON MINE.

The Nickelson mine is three-quarters of a mile north of Montvale. 

The workings had fallen in badly and little could be seen of the
268 MICA DEPOSITS OF THE UNITED STATES.

formations. The body of pegmatite appears to be conformable with 

the inclosing mica gneiss. The mica was dark, smoky, and in part 

of the A variety.

J. P. Hinkle has opened a mica prospect about a mile southeast of 

Montvale. Crystals of mica 2 to 3 inches across were seen here in.a 

3-foot " vein " of pegmatite. The pegmatite has a N. 30° E. strike 

and a vertical to high easterly dip. Another prospect was opened 

about 300 yards east of south from the Hinkle prospect. The mica 

from these prospects is dark and is in part specked.

WAKE COUNTY.

A prospect was opened for mica about 3 miles southwest of Wake 

Forest early in' 1916 by J. E. Coggins, of Raleigh. When the place 

was examined in June, 1916, there was a pit about 10 feet across and 

5 feet deep. The country rock is granite, slightly gneissic in places. 

The mass of pegmatite exposed in the walls of the pit is from 1 foot 

to 3 feet thick, and is very irregular in size and shape. It grades 

into the surrounding granite by diminishing coarseness of texture.

The pegmatite is composed of partly altered potash feldspar in 

crystals that reach a thickness of 1 foot, dark, smoky quartz in 

irregular-shaped masses from less than 1 inch to 18 inches thick, and 

crystals of mica, some of which are as much as 10 inches across. One 

crystal of mica taken out is reported to have weighed about 75 

pounds. Mica weighing between 400 and 500 pounds was removed 

from the pit. Part of this is of the A variety, part is tangle sheet, 

and a little is ruled. Clear sheets 2 by 3 inches, 3 by 3 inches, and 

probably larger can be cut between A lines from parts of the larger 

crystals. The mica is clear where free of clay stains and has a 

smoky, greenish color.

WARREN COUNTY.

A little mica mining was done in the "Forks" region, south of 

Inez, Warren County, about 1880. A trimming plant was set up 

and the mica was cut into patterns on the William Connell property, 

about 2£ miles southeast of Inez. A sufficient number of mica 

plates of the large sizes then required could not be obtained, and 

the work was abandoned. Such mica as was found would perhaps 

now be valuable.

Rocks characteristic of mica regions that is, mica schists and 

gneisses occur in this area, but the predominant rock is granite. 

Belts of mica gneiss occur between Warrenton and Inez and south 

of Inez. Small crystals of mica were seen in the outcrops of pegmatite in these formations in this area, and crystals of beryl have 

been found on the land of Mrs. Jennie Connell, 2 miles southeast of 

Inez.
NORTH CAROLINA. 269 

AVATAUGA COUNTY. 

DOBBINS MINE.

The Dobbins mica mine is 2 miles north of west of Elk Crossroads. It was operated extensively about 1890 and on a smaller 

scale ten years later by the Blue Ridge Mica Co. There are two 

sets of workings 250 yards apart, one at the foot of the hill and 

the other on top of the ridge to the northeast. The work done 

near the road consists of five tunnels, two shafts, and some groundhog openings. The tunnels have been run in at different levels 

on the hillside, in a space about 70 feet wide on a large body of 

pegmatite. These tunnels, which have been run in directions ranging 

from N. 25° E. to N. 45° E., show roughly the trend of the body of 

pegmatite. The country rock is biotite gneiss, which strikes between 

N. 30° E. and N. 40° E., and has a nearly vertical dip. The body 

of pegmatite is conformable, or nearly conformable, with the inclosing gneiss. Some parts of the pegmatite that were exposed 

in the workings were rich in small mica, but others contained little 

or no mica. The openings on the ridge consisted of three shafts and 

tunnels on each side of the summit. They were confined to a belt 

about 100 yards long and about 40 feet wide, extending N. 35° E. 

One deep shaft had been well timbered and was in a good state 

of preservation, but the other openings had caved badly. Little 

mica had been left around these workings. Most of that seen at 

the openings along the road was dark brown to greenish brown. 

Part was specked and in wedge-shaped blocks with the A structure. 

Some clear sheets were seen with good cleavage but of rather dark 

color.

Charlie Todd owns a mica mine 1$ miles northwest of Elk Crossroads. The mine has not been opened for 15 years. The pegmatite is marked by the outcrop of massive quartz. R. H. Clawson 

prospected for mica about a quarter of a mile northwest of the Todd 

mine in 1904.

LOOKE GBEEN MINE.

Mrs. Locke Green owns a mine on the south end of the knob of 

Deep Gap oi the Blue Ridge Mountains, west of Stony Fork. It 

is said that a 50-foot incline driven on this vein yielded chiefly 

specked mica.

ABTHUR WELCH MINE.

The Welch mine is about half a mile west^of Stony Fork post 

office, on the headwaters of Stony Fork Creek. Some prospect 

pits were dug here about 1895 and two more in 1905. These pits 

disclosed a deposit of good pegmatite with granitic gneiss wall rocks
270 MICA DEPOSITS OF THE UNITED STATES.

in a region of mica gneiss country rock. The pegmatite is probably 5 feet thick and contains streaks of quartz as much as a foot 

thick. The strike of the inclosing rock is about northwest and the 

dip is 45° NE. Most of the mica is heavily specked with magnetite and has a dark clear green color. Blocks 5 or 6 inches in 

diameter, weighing sever.al pounds, were seen.

F. A. LINNEY MINE.

The Linney mine, sometimes called the Rich Mountain mine, is 

1/| miles northwest of Boone, on the steep side of a mountain cove. 

The chief working is an open cut near the top of the hill, but three 

other pits have been made east of this at a lower level. The country 

rock is mica gneiss, which strikes from east to N. 75° E. and dips 

30° N. Mica of good quality and fine rum color was found. Sheets 

of mica as much as 6 inches across were seen, though the small 

sizes predominated. Another prospect was on F. A. Linney's land 

half a mile north, near the Foster mine. Good mica is reported 

from this locality and from other places in the same neighborhood.

ARNEY FOSTER MINE.

The Foster mine is on Doe Eidge 2 miles N. 20° W. of Boone. 

Openings have been made here at three places within a quarter of 

a mile of one another. In one of these openings, west of the house, 

a ledge of pegmatite. 8 feet thick was exposed. It was inclosed in 

biotite gneiss striking northeast and dipping 15° SE. Both muscovite and biotite are found and in some places they are intergrown. 

South of the house an opening exposed streaks of pegmatite inclosed in biotite gneiss striking N. 60° E. and dipping 30° NW. 

The mica found at these prospects has a clear rum color, but most 

of it is small. East of the house open cuts had been made and a 

tunnel run in for a short distance. Part of the mica found here was 

black specked.

C. 0. GREEN PROSPECT.

The Green prospect is 3f miles north of Boone, on the road from 

Norris to Silverstone. The pegmatite has been opened by several 

small pits. The country rock is biotite gneiss, which strikes north 

and dips vertically. Bands of hornblende gneiss are included in the 

country rock, and pegmatite is common in the region. Small sheets 

seen on the dump indicate that mica of good quality had been found. 

Sheets of biotite 2 inches in diameter were also seen. Other prospects were opened in this region on the land of Richard Norris, 

Manly Green, and the Wall brothers.
MOUTH CAROLINA. . 271

WILKKS COUNTY. 

JOEL TRIPLET! MINE.

The Triplett mica mine is on Stony Fork near Hendricks, 16 miles 

from Wilkesboro. Here there are three mica prospects, one of which 

was opened several years ago by a tunnel 40 feet long. The workings exposed a body of pegmatite about 8 feet thick that was approximately conformable with the mica gneiss country rock, which 

strikes N. 30° E. and dips 35° SE. and contains numerous small 

lenses and masses? of quartz and pegmatite. Mica was segregated 

in small blocks along the walls of the pegmatite. About 50 pounds 

of sheet and cut mica was seen. The sheets ranged in size from 2 

by 2 to 4 by 4 inches. The mica varied from clear sheets with good 

cleavage to smoky or specked and A mica. The color of the best 

was rather dark greenish brown in sheets a sixteenth of an inch 

thick or more.

TADKIN COUNTY. 

HATJSER MIKE.

A new locality for mica in North Carolina was brought to the attention of the writer in 1913 by Mr. George H. Hauser, of WinstonSalem. It is in Yadkin County, about 6 miles east of Yadkinville, 

and most of the prospects that have been opened are on land owned 

by Mr. Hauser. An itinerant miner located the prospects several 

years ago and after ground-hog mining at a number of them abandoned the work. The country is a rough part of the Piedmont 

Plateau and much of it is covered with timber. The country rock is 

diorite, in places strongly schistose.

The best deposit tested is about half a mile south of the main road 

leading west into Yadkinville. It was worked by numerous pits, 

trenches, and cuts and one shaft 40 feet deep within an area 250 

yards long northwest to southeast and 200 feet wide, as shown in 

figure 77. Outcrops of pegmatite carrying mica and another pit lie 

outside of this area. The exposures were not so good as to permit 

the determination of the relations between the pegmatite and the 

inclosing schistose diorite. In a pit across a branch on the northeast 

side of the mine the country rock is cut by a body of pegmatite having a northeast strike and a vertical dip. The country rock strikes 

northwest and has a vertical to high northeast dip. The position of 

the workings indicates either an irregular body of pegmatite with 

arms branching out, several veins, or a large blanket ledge (or ledges) 

from which there are offshoots of smaller veins. The appearances 

suggest one or more beds of pegmatite cropping out on the hillside 

with a low dip to the northeast. If the conditions are those indicated
272 MICA DEPOSITS OF THE UNITED STATES.

the deposit could be very effectively mined by open cuts and drifts 

from this hillside.

Large blocks of white, gray, and smoky quartz, some translucent 

and some nearly clear, were removed during mining. Some of this 

quartz shows imprints of numerous mica crystals. Semikaolinized 

feldspar was encountered in many of the workings, and an outcrop 

of pegmatite along the branch contains solid crystals of microcline 

18 inches across, with small mica. In the principal workings mica 

seems to have been fairly plentiful. Only small crystals had been 

left around, but these were mostly of good quality, having a clear 

brownish-green color and very good cleavage. Some was slightly 

specked. Some of the blocks have good crystal outline with fairly 

sharp faces, especially the crystals adjoining massive quartz. A few

FIOUBK 77. Plan of Hauser mica mine, 6 miles east of Yadkinvllle, Yadkin County, N. C.

larger crystals of mica, measuring from 4 to 6 inches across, found 

on the dumps, were badly crushed and had a very imperfect cleavage. 

Some of these included numerous small crystals of mica penetrating 

the laminae at various angles. In the two pits at the northwest 

end of the workings much A, wedge, and fishbone mica was found. 

Masses of tangled blocks of this mica, measuring several inches 

across, had been left around the pits, but such material would be 

suitable only for grinding.

Another prospect was opened near a branch on the point of a low 

ridge a quarter of a mile southeast of this mine. A cut 6 feet deep 

and 20 feet long in a N. 70° W. direction was made on the north 

side of the ridge, exposing a pegmatite dike about 10 feet thick 

with a strike of N. 70° W. and a high dip to the south cutting
NORTH CAROLINA. 273

schistose diorite. Most of the mica seen was in bunched masses 

of wedge and A crystals. Some slightly specked small-sheet mica 

was also seen. The pegmatite contains feldspar crystals a foot thick, 

but most of the rock is very uneven grained.

Another mass of pegmatite crops out on the hillside about 100 

feet to the north, across the branch. This pegmatite is 8oarse grained 

and from it crystals of mica from 2 to 3 inches across have weathered out.

YANCEY COUNTY. 

GIBBS MINE.

The Gibbs mica mine is on the west side of South Toe River, 2 

miles south by west of Newdale, Yancey County. It was operated 

on a large scale until 1906 by the J. E. Burleson Mica Co., and was 

then abandoned for mines where mica could be obtained with less 

difficulty.o The entrance to the mine is on a hillside, about 75 feet 

above the river. The work consisted of an incline on the dip of the 

" vein " carried down more than 500 .feet. The incline has a grade 

of about 35° for the first 150 feet from the surface and about 25° 

below this. For about two-thirds of the length of the incline the 

" vein " has been removed for a width of 40 feet. Pillars were left, 

and a few stulls were placed as supports. The workings off to the 

sides of the incline were irregular, consisting of short tunnels, rooms, 

or stopes where rich "leads" of-mica were found. The "vein" was 

first removed for a thickness of 7 to 10 feet in the upper part of the 

mine, and then for the full thickness of 15 feet or more in the lower 

part. Hoisting was done by a steam engine with a track and skip. 

The skip was used as a pump also and satisfactorily handled the mine 

water.

The pegmatite formation is large and is more continuous than at 

many other mica mines in North Car.olina. It is conformable with 

the bedding of the inclosing mica gneiss, striking about N. 50° W., 

and dipping 35° SW. at the surface, and less with increase of depth. 

The feldspar of the pegmatite is a plagioclase carrying soda and some 

calcium and is probably oligoclase. Most of it is pure white, though 

part is transparent and has a pale aquamarine-green color. Other 

minerals of the pegmatite are quartz, muscovite, biotite, and a little 

garnet and apatite. The texture of the pegmatite is granitic and 

fairly coarse. Masses of feldspar crystals weighing 200 pounds were 

seen on the dump, and blocks of mica of similar weight are sometimes 

obtained. The quality of mica from the Gibbs mine is the finest, and 

the thick sheets have a rich rum color. The crystals generally run 

from 3 to 12 inches in diameter. Still larger sheets are sometimes 

obtained. At the time the mine was examined in 1905, the produc-
274 MICA DEPOSITS OF THE UNITED STATES.

tion amounted to about 1,000 pounds of good block mica a week, 

though at times larger quantities were obtained..

POLL HILL MINE.

The Poll Hill mine is If miles south by west of Newdale, on 

the east side of South Toe River, just across the river from the 

Gibbs mine. This mine consists of two' parts, both of which have 

been operated intermittently and actively since 1906. The part near 

the bank of the river was worked by the Burleson Mica Co., and that, 

higher up on the hill by Hall Bros. & Burleson. The part near the 

river was being cleaned out at the time the mine was visitedy 

and was equipped with a steam pump and hoist. The workings 

consist of an incline about 20 feet deep on the pegmatite and a 

tunnel northeast of it. The country rock is mica gneiss, which 

strikes about N. 75° E. and dips 55° S. The pegmatite is only approximately conformable with the gneiss and so far as seen ranges

Face at end 

of incline (OL)

Plan Cross section

FIGURE 78.- -Plan of Poll Hill mica mine, Yancey County, N. C., and cross section of 

pegmatite at end of incline.

from 10 to 15 feet in thickness. It contains numerous small horses 

or streaks of mica gneiss or schist, which lie parallel with its Walls.

The upper part of the mine' has been worked at several places, 

and in such positions as to show an irregular pegmatite formation 

or several masses of pegmatite. The last operations had been in 

progress about one year at the time the mine was visited, and the 

nature of the work is shown in figure 78. A 70-foot tunnel was 

driven in a N. 75° E. direction on a "vein" of mica. From this 

tunnel an incline was run south westward on a dip of about 35°. 

The incline was about 70 feet long, 20 feet wide, and 10 feet high. 

A bench was left on the northwest side in barren rock. The waste 

andonica were hoisted from the incline by means of a hand whim at 

the head of the incline.

The wall rock is biotite gneiss, through which the pegmatite cuts 

and into which it forks out. Figure 78 shows also the vertical
NORTH CAROLINA. 275

cross section of the pegmatite exposed in the face at the bottom 

of the incline. The position of the bench in barren gneiss is shown 

on the side. The incline was driven on the pegmatite where that 

rock was diverted from its course across the gneiss into lens-shaped 

masses. These lenses became smaller or pinched out in a short 

distance on each side.

The quality of the mica from the Poll Hill mine is good and the 

color a clear rum. o

ALEY MINE.

The Aley mine is at the head of Browns Creek, about 3 miles 

southwest of Micaville. It has been opened by at least three tunnels, 

one an incline, and by open cuts and a shaft 40 feet deep. The last 

work was that of the J. E. Burleson Co. in 1904. The "vein" 

strikes N. 15° E.. and has a high easterly dip. It has been opened 

along its strike for nearly 100 yards up the side of the mountain. 

The lowest opening is an old tunnel run in on the " vein " for drainage and development. A shaft that was started higher up the hill 

to meet this old tunnel never was completed. At the time the 

mine was visited a block of mica weighing nearly 100 pounds was 

found in the bottom of the shaft and several other fine blocks of 

mica were found within 3 feet of the surface in a cut east of the 

shaft. Some of these blocks may have been drift, from the outcrop 

of the " vein" above, though they were probably derived from a 

second "vein" parallel to the first. A corresponding "vein" has 

been opened by an incline lower down on the hill, above and east 

of the drainage tunnel. The mica from this mine has a rich rubyred to rum-red color and is of excellent quality for use in stove 

windows.

YOUNG MINE.

The Young mine is about 2 miles west of Boonford and 100 yards 

west of South Toe River. The mine has been opened for a distance 

of more than 200 feet by cuts, pits, tunnels, and shafts covering a 

width of more than 50 feet. The workings extend from the south 

side of a ridge about 100 feet high over the top to the north side. 

The mine was operated in 1904^-5 by the J. E. Burleson Co. The 

country rock is hornblende gneiss, biotitic near the contact with 

the pegmatite. The pegmatite outcrop crossing the creek on the 

south side of the ridge is about 100 feet wide. The strike of the 

formations is about N. 35° E. and the dip is 75° SE. Streaks or 

horses of mica schist are included in the pegmatite and are parallel 

with it in strike. The mica occurs in streaks parallel with these 

horses of schist, which are in some places left as walls to the workings. The " veins " have yielded a large quantity of mica in small
276 MICA DEPOSITS OF THE UNITED STATES.

sheets and some in large sheets. The mica is of good quality and 

said to be especially fitted for making electric appliances.

BAILEY MOUNTAIN MINE.

The Bailey Mountain or White mine is about 1£ miles east of 

Celo, on the public road close to South Toe River. Here several 

deposits are grouped together, some of which have been worked. 

One of these was reopened in 1906 by Bergen, Shuford, Washburn, 

and Myrtaugh. The old workings consist of numerous tunnels and 

open cuts carried for 200 yards up and down the hillside, both above 

and below the public road.. A large opening was made on the lower

side of the road. The new work consists of 

a crosscut trench about 30 feet above the 

river level and an open cut on a " vein" 

below the old workings. The country rock 

is biotite-mica gneiss, which strikes N. 15° 

E. and dips 25° W. The "vein" exposed 

in the new workings is conformable with 

the inclosing gneiss and ranges in thickness 

from 18 inches to 5 feet. This pegmatite is 

evidently another mass than that opened 

directly above or it is a fork from the main 

body of pegmatite. The mica is somewhat 

evenly distributed through the pegmatite. 

It is dark brown and some is a little specked. 

Part is of good quality and part is suitable 

only for making electric appliances.

HENSLEY MINE.

FIGDRB 79. Vertical cross 

section of pegmatite at 

Hensley mica mine, Yancey County, N. C.

The Hensley mine is on Pigpen Creek, 

about 2 miles south by Avest of Green Mountain. It was operated by the Hampton Mining Co. in 1906, when the accompanying notes were taken. It is said 

that there were ancient workings at this mine, which was also worked 

before 1906 by white people. The country rock is mica gneiss, which 

strikes north and has a nearly vertical dip. The pegmatite is conformable or nearly conformable with the schistosity of the inclosing rock. It occurs in lens-shaped masses 3 to 4 feet thick. The 

mine has been opened by two shafts, 40 and 45 feet deep and 15 feet 

apart, each having evidently been sunk on a rich lens. In the space 

between the shafts, partly worked out, the overlapping of two lenses 

was well shown. (See fig. 79.) The gneiss and schist walls bend 

around the lenses. Fifty feet south of the shafts an open cut exposed a lens 2£ feet thick and about 15 feet long, lying in the gneiss. 

Blocks of mica that weighed many pounds have been found. Part 

of the mica is clay and iron stained near the surface and is used
NORTH CAEOLUSTA. 277

Mica 

gneiss

for electric appliances, and part has a clear amber color and is suitable for stove windows.

CATTAIL BRANCH MINE.

The Cattail Branch mine is near the head of Cattail Branch, 

nearly a mile southwest of Celo Mountain, at the north end of the 

Black Mountains, about 5,500 feet above sea level. It was discovered 

about 1904 by Silvers & Son and B. Eolland, of Yancey County. 

The mine was examined in 1906, when the following description was 

prepared. The developments consist of open cuts at three different 

points on the outcrop. The country rock is biotite gneiss, which 

strikes northeastward. Near the pegmatite it is much flexed and 

of an inclined trough having a horseshoe or 

U-shaped cross section.

The bottom of the trough pitches about 55C 

SW. and cuts directly across the country rock. 

The sides are nearly vertical and at a little distance from the bottom of the trough conform in a 

general way with the strike of the country rock. 

Figure 80 is an attempt to represent the shape 

of the pegmatite, A being a plain view and B a 

perspective view.

The thickness of the pegmatite ranges from 

3 feet in the curve of the horseshoe to 20 feet 

or more some distance out from the curve. This 

measurement includes horses or tongues of wall 

rock around which the pegmatite has forked. 

About 30 feet southwest of the curve the west 

arm is nearly 25 feet thick, the greatest thickness exposed. The "vein" must have bulged 

out abruptly to attain so great a thickness at this point. It contains mica gneiss bands or horses from a few inches to several feet 

in thickness, oriented parallel to the walls. The southeast arm shows 

a similar bulging, being about 12 feet thick at a distance of 25 feet 

from the curve.

The texture of the pegmatite is very coarsely granitic. The larger 

part of the mica is found in the interior of the pegmatite, though 

some is scattered along the walls. Its quality is excellent and its 

color is a beautiful rum. The yield in larger sizes is good, and 

smaller sizes are plentiful.

LETTERMAN MINES.

M. P. Letterman owns two mines about 1£ miles southwest of Daybook, on the mountain ridge between Pigpen Creek and Mine Fork.

111375 23 10

mine, Yancey County, 

N. C. A, Plan> view; 

B, perspective view.
278 MICA DEPOSITS OF THE UNITED STATES.

Both these mines were operated during 1905 and 1906. The principal 

mine, which is on the Pigpen Creek side, was operated by George 

Bartlett for Berry & Patrick, of Spruce Pine. The workings consist 

of a tunnel driven 150 feet along the " vein," an old shaft, and a pit. 

The country rock is biotite gneiss, with which the pegmatite is approximately conformable. The body of pegmatite is about 8 feet 

thick in the thinnest part opened and swells to 12 feet in the thickest. 

It crops out on the hillside, in a course about due north, which, however swings to S. 35° E., where it was followed into the hill. It 

stands nearly vertical. The streak or " vein " of mica is in the middle 

of the pegmatite and is about 3 feet thick in its thickest part. The 

pegmatite along the walls is said to be nearly barren of mica. Greenish (copper-stained) feldspar with a streak of garnet and pyrite 

lies along the east wall. Mica was plentiful along a quartz vein encountered in the pegmatite. It is .found in rather thin, flat, fairly 

large blocks, has a red rum color, and is of good quality.

Another mica deposit has been opened in the past by a shaft 

and tunnel about 300 yards to the southeast, lower down on the 

mountain side.

The deposit on the Mine Fork side of the mountain was opened 

by M. P. Letterman by two small tunnels, run within a short 

distance of each other, and a prospect pit. One of the tunnels was 

on a streak of A mica and the other exposed a flat rum-colorfed 

variety. The pegmatite, which is conformable with the hornblende 

gneiss country rock in these openings, strikes N. 30° E. and dips 

10° SE. The pit was about 100 yards southwest of the tunnels. Here 

a streak of pegmatite 18 to 20 inches thick was encountered in biotite 

gneiss, which strikes N. 45° E. and dips 80° SE. The pegmatite 

contained considerable quartz, which was in the feldspar, and yielded 

some beryl and columbite. One fractured crystal of columbite weighing 6 pounds and smaller fragments, weighing in all about 30 

pounds, were seen.

A mine was operated in 1906 on the land of Wesley Higgins, on 

the Mine Fork side of Green Mountain, nearly 1 mile south of 

the Letterman mines and 2| miles northeast of Burnsville. The 

work was done by Grover Huskins and consisted of an open cut 

nearly 100 feet long and about 20 feet deep in its deepest part. 

The mica is reported to be of rum color, but only part of it is 

suitable for electrical use.

An old mine at the head of East Fork of Pigeon Creek was reopened by J. S. Huskins in 1906, and two new tunnels, one 50 feet 

and the other 100 feet long, were driven on the hillside, across and 

along the " veins." About 100 yards higher up the hill an incline 

had been sunk some time before. The mica is rum-colored but is 

soft, and most of it is used for electric appliances.
PENNSYLVANIA. 279 

BAY MINE.

The Ray mine, a little more than 2 miles S. 35° E. of Burnsville, 

was opened by Garrett D. Eay in 1869. It was operated until 1885 

and was then closed down until 1914, when part of it was reopened by J. E. Burleson. Mr. Ray estimated that about 100,000 

pounds of mica of first quality, worth $125,000, was removed from 

the mine during his operations. The mine has been famous for its 

large yield of beryl crystals suitable both for cabinet specimens and 

for cutting into gems. It was worked by several shafts from 50 

to 250 feet deep in a distance of about 400 yards along the " vein."

According to D. M. Glenn, of Phenoy, a little work was done 

in 1905 on his mine on the west side of Crabtree Creek, 3 miles east 

of Celo. Flat mica with A markings was obtained. It has a dark 

smoky-brown color with a greenish tint, and part of it is specked. 

Uranium minerals are also reported to have been found, and their 

yellowish-green stain was seen on specimens at Mr. Glenn's house.

PENNSYLVANIA. 

GENERAL FEATURES.

From time to time small quantities of mica have been mined in 

Pennsylvania. Deposits occur in Berks, Lehigh, Chester, and Delaware counties. There are early references to mica mining near 

Reading 70 and on South Mountain near Newmanstown,71 and a 

mine was worked many years ago on Blackhead Hill, 7-£ miles N. 

5° E. of Boyertown, in Berks County. Prospects are reported by 

E. F. Bliss and A. I. Jonas about 7 miles N. 10° W. of Boyertown, 

near Landis Store, and &| miles N. 75° W. of Quakertown. Prof. 

B. L. Miller, of Lehigh University, mentions an old mica prospect, 

opened in 1883, about 1-J miles southwest of Seidersville, in Lehigh 

County.

Other deposits have been worked in Chester and Delaware counties. A little mica has also been obtained from quarries worked for 

feldspar in these counties. The feldspar quarries have been described by E. S. Bastin.72 Two of the deposits in Delaware County 

were visited by the writer in 1915 and are briefly described below.

DELAWARE COUNTY. 

KASSON MICA CO.

Mica was mined by the Kasson Mica Co., of Camden, N. J., 1£ 

miles east of Glen Mills, 4 miles west of Media, in 1913. The de-

 Eng. and Min. Jour., vol. 40, p. 47, 1885.

71 Mica: U. S. Geol. Survey Mineral Resources, 1885, pp. 518-520, 1888.

72 Feldspar deposits of the United States : U. S. Geol. Survey Bull. 420, pp. 63-72, 1910.
280 MICA DEPOSITS OF THE UNITED STATES.

posit here was discovered and first worked by John H. Smedley, of 

Media, sometime prior to 1870. Mr. Smedley says that he shipped 

about 250 tons of mica. The operations of the Kasson Mica Co. 

for several months in 1913 resulted in an output of more than 50 

tons, most of it scrap mica.

The workings consisted of an open cut 80 feet long driven N. 60° 

E. into a southwestward-sloping hillside. This cut is 15 to 35 feet 

wide, and 5 to 20 feet deep to water in a shaft or stope in the bottom. 

The mine was idle at the time it was examined in 1915 and the 

possible extent of underground workings could not be ascertained. 

Old, overgrown dumps have been built out on the bank of a ravine 

50 to 75 yards south of the open cut, but the source of this material 

was not evident.

The country rock is gabbro, which, according to F. Bascom, is 

of early Cambrian or pre-Cambrian age. The gabbro has a somewhat 

schistose structure-, and incloses interbedded mica gneiss. These 

rocks have a northeast strike and variable southeast dip. There is 

one large deposit of pegmatite with smaller parallel beds on either 

side. These beds cut the gneiss with a strike of about N. 60° E. and 

a vertical dip. The main pegmatite is at least 12 feet thick and 

probably thicker near the middle of the open cut. It is coarse 

grained in places and contains masses of feldspar several feet thick, 

quartz in segregations and veins from a few inches to 2 feet thick, 

and mica in crystals some of which were nearly a foot across. Most 

of the feldspar is the flesh-colored potash variety, but some is white 

fine-grained plagioclase. Hough wedge-shaped mica crystals 10 

inches in diameter were seen and smaller crystals from 4 to 6 inches 

across, with a fair cleavage over parts of the crystal, were found. 

Some of these crystals, however, contained a large proportion of 

tangle-sheet mica. The mica has a medium-dark, smoky-brownish 

color and part is specked.

CHESTER HEIGHTS DEPOSITS.

Several deposits of pegmatite, have been worked for feldspar near 

Chester Heights. Some of these are on the north side of the railroad about one-third of a mile west of Chester Heights station, and 

others are on the south side of the railroad about one-third of a mile 

southwest of Chester Heights. Only one of the quarries was in operation at the time of the examination, in 1915. Part of the feldspar 

from these quarries is very pure and is used in dentistry. The 

quarry in operation is about 250 yards northeast of the railroad, on 

the Aston-Concord township line.

TC U. S. Geol. Survey Geol. Atlas, Philadelphia folio (No. 162), 1909.
SOUTH CAROLINA. 281

The country rock as mapped by F. Bascom T4 is mica gneiss of the 

Wissahickon gneiss formation, into which has been intruded masses1 

of gneissoid diorite or gabbro. These rocks strike east of north 

and have a high easterly dip. The pegmatite forms large deposits, 

which cut the inclosing gneiss both parallel and at angles with the 

bedding. Both rocks have been partly decomposed, but in places 

the pegmatite outcrops in hard, fresh masses. The pegmatite ranges 

from fine grained to coarse grained and contains crystals of pinkish 

feldspar 2 to 3 feet thick. It contains also some finer-grained white 

plagioclase feldspar and some biotite. Crystals of mica are scattered in pockets and streaks through the pegmatite. At the time of 

the examination mica suitable only for cutting into small sheets, for 

punching, and for grinding was seen, but some crystals 15 to 18 

inches in diameter are said to be found. The mica has a clear, rather 

dark green color and good cleavage.

BRANDYWINE SUMMIT FELDSPAR CO.

According to E. S. Bastin 75 the Brandywine Summit Feldspar Co. 

has operated a quarry 1-J miles south of Brandywine Summit station, 

where three large pits have been opened in an area of about 4 acres. 

Cream to flesh colored orthoclase and microcline feldspar occur in 

pure crystals, some of them a foot thick. No graphic 'granite was 

seen. Quartz occurs in rather small granular gray masses. Mica 

occurs in crystals of sizes up to 18 inches across, but none of it is 

suitable for use in sheets. The smooth sheets of this mica are specked 

between the laminae with thin films of magnetite.

SOUTH CAROLINA. 

GENERAL FEATURES.

Earle Sloan 76 describes several deposits of mica in South Carolina 

and gives the location of others. Most of these deposits lie in the 

Piedmont Plateau, in Oconee, Anderson, and Greenville counties. 

Some of them have been worked on a fairly large scale and have 

yielded good mica. A brief examination of those described below 

was made in October, 1913.

The rocks seen in the region around the mica mines consist mainly 

of mica schist and mica gneiss, with which are associated some 

kyanitic and garnetiferous rocks, and diorite, hornblende schist, and 

granite gneiss. The mica and garnet schists and gneisses are probably parts of the Carolina gneiss, which is described by Keith in the

74 U. S. Geol. Survey GeoL Atlas, Philadelphia folio (No. 102), 1909. 

7B Feldspar deposits of the United States: U. S. Geol.'Survey Bull. 420, pp. 70-71, 1910. 

7* Catalogue of the mineral localities of South Carolina: South Carolina Geol. Survey 

Bull. 2, 4th sen, pp. 142-149, 1908.
282 MICA DEPOSITS OF THE UNITED STATES.

Geological Survey's geologic folios covering areas in western North 

Carolina (folios 90,116, 124,143,14T, and 151). In this part of the 

Piedmont Plateau weathering has been extensive, and in places the

rocks are decomposed to 

depths of many feet.

ANDERSON COUNTT. 

GAILLARD MINE.

A deposit of mica has 

been worked extensively 

on the Warren Gaillard 

place (formerly the J. J. 

Fretwell place), about 

6 miles S. 75° W. of 

Starr, at two different 

periods, but the mine 

was idle at the time it 

was examined. The 

principal workings fall 

within a distance of 

about 900 feet in a line 

extending N. 20° E., as 

shown in figure 81. 

Eight shafts, ranging 

in depth from 15 to 40 

feet, and several pits 

have been made. Drifts 

were run from the shafts 

and stopes wherever 

rich vein material was 

of the workings have caved in and could not be

The country rock as exposed in the branch south of the mine is 

strongly folded biotite gneiss, into which is injected granite and 

pegmatite. The strike and dip are variable, but the strike averages 

northeast and the dip southeast. The gneiss and the pegmatite 

exposed in the workings are both deeply weathered. Masses of white 

quartz were encountered in the three main groups of workings. 

In the middle group the quartz is still exposed as an irregular vein, 

2 to 8 feet thick, inclosed in the decomposed pegmatite and lying 

about 3 feet from the west wall of the vein. In places the quartz 

is gray, and some of it is smoky. The thickness of the pegmatite 

varies, being at least 18 feet in the middle workings and probably 

ranging from about 8 to 25 feet, including streaks or horses of mica

100 aoo 300 Feet

Approximate contour interval ISfeet

FIGURE 81. Plan of Gaillard mica mine, 6 miles S. 

75" W. of Starr, Anderson County, S. C.
SOUTH CAROLINA. 283

gneiss. Whether the three main groups of shafts and the tunnel 

to the south are all on the same body of pegmatite could not be 

determined. The mica is evidently pockety and irregularly scattered 

through the pegmatite but is most plentiful in the decomposed feldspar next to veins and masses of quartz. Some of it is partly intergrown with quartz. Most of the mica seen was either in small 

crystals or in larger crystals cut by ruling into ribbons and small 

plates. Crystals yielding sheets 10 inches square are reported to 

have been obtained when mining was in progress. The mica is 

clear and of good quality, splitting well.

Several tons of scrap mica could be obtained by screening and 

washing the waste mixed with kaolin on the dumps, and if such material had been saved during the first operations it would have gone 

far toward defraying the cost of mining.

A shaft sunk about 150 feet west of the main workings struck a 

body of pegmatite like that in the main workings, and a quantity 

of small mica was removed.

FRETWELL PROSPECTS.

Prospecting has been done on the old Hall place, now owned by 

J. J. Fretwell, about 1| miles west of Barnes, where a belt of mica 

has been traced for nearly a mile northeastward. Three deposits 

that crop out on small knolls about 200 yards apart were examined. 

The pegmatite crops out as white gravelly quartz soil, through which 

are scattered blocks of white quartz and plates of mica. This soil 

can be traced rather plainly over the fields, because it contrasts with 

the darker earth and red clay soil formed by the decomposition of 

the inclosing schists. The outcrops trend about N. 60° E., as shown 

in figure 82. They are probably on separate bodies of pegmatite and 

do not represent one continuous mass. The country rock is mica 

gneiss, which includes many layers ,of schist. Both the mica gneiss 

and the pegmatite have been deeply weathered.

Practically no work has been done on the middle and southwest 

masses of pegmatite, but weathered sheets of mica are abundant at 

the prospects marked X in figure 82. An opaque crystal of yellowish beryl was found at the place indicated in the sketch map. 

At the northeast end of the area examined two prospect pits had been 

opened on each side of a small gully. Nothing could be seen of the 

pegmatite in the pit on the south side, but the later work on the 

north side, at the place marked A in figure 82, yielded some mica. 

A cross section of the formations encountered at this place is shown 

in the figure. The pegmatite appears to be a nearly horizontal bed 

inclosed in mica schist, but it may have an easterly strike and a 

northerly dip. The mica schist on the west wall strikes north by
284 MICA DEPOSITS OF THE UNITED STATES.

east and dips about 25° E. Fifty feet west of the prospect the schist 

strikes N. 40° E. and dips 35° SE. Blocks of massive white quartz 

lie east of the prospect. The mica occurs in pockets or in bunches 

of crystals, or is scattered irregularly through the pegmatite. Crystals of mica as much as 8 inches across have been found, and specimens were seen that would cut to 2 by 3 inches. The mica obtained 

near the surface is rather badly clay stained, but the better pieces are 

of a clear light rum color and have good cleavage.

The pegmatite is decomposed and can be easily excavated. The 

deposit should be prospected by a cut run back into the north side 

of the gully as far east as mica can be found, and further work 

should be carried on at places where the showings of mica are best.

Another mica prospect has been opened on land owned by Mr. 

Fretwell, on the northeast bank of Savannah Kiver about a quarter of a mile

Mica schist 

Pegmatite

FIG ORB 82. Outcrops at Fretwell mica prospect,

Barnes, Andersen County, S. C. A,. Sketch plan; B, cross section at prospect marked A.

above the mouth 

of Big Generostee Creek. This 

prospect is 

about a mile 

south of the 

Gaillard mine, 

7 miles S. 65° 

W. of Starr. 

An open cut 

miles west of made years ago 

around an outcrop of quartz

on the hillside revealed pegmatite with crystals of mica of promising size and crystals of potash feldspar 18 inches across. Bluishgreen and yellowish crystals of beryl were found, one of which was 

more than 4 inches in diameter. A 30-foot tunnel was driven in 

under the open cut, but without encouraging results. The country 

rock is fine biotite gneiss and is cut irregularly by the pegmatite.

WHAKTON MINE.

Mica was mined several years ago on the Sam Wharton place, 6^ 

miles N. 82° W. of Iva. The workings consisted of an open cut 

40 feet long run N. 60° E. along the northwest side of a small branch, 

two crosscuts from the hillside, and a crosscut tunnel with a room 

at the end a few feet northeast of the open cut. The country rock 

is decomposed mica schist inclosing streaks of hornblende schist 

striking northeast and having a variable dip. The pegmatite cuts 

the country rock irregularly and pinches from a thickness of 15
SOUTH CAROLINA. 285

feet in the open cut down to a few inches in the tunnel at the northeast end of the workings. The rocks are weathered and are easily 

excavated. Rough sheets of mica 8 inches across were seen on the 

dump, and a few pieces were found that would cut 2 by 3 inch 

plates. This mica has a greenish cast and splits well.

Another prospect pit was made 200 feet west-southwest of the 

main workings. Blocks of hard pegmatite containing small mica 

were left on the dump.

SHERARD MINE.

Mining has been carried on intermittently on the old Vandiver 

Sherard place, 6£ miles N. 80° W. of Iva, about a quarter of a mile 

southwest of the Sam Wharton mine, on the same belt of mica deposits. The first working was a 30-foot shaft from which drifts 

were run. Later a 25-foot shaft was sunk about 100 feet N. 20° E. 

of the first shaft, and drifts were run to the north and south. A crosscut tunnel 140 feet long was next driven in from the hillside below, 

on the east, and the mine was worked through it. About 70 feet 

from the portal this tunnel cut another vein, on which drifts were 

run. After this crosscut tunnel caved in a new shaft was sunk west 

of the vein to a depth of 35 feet, and a crosscut was made to the vein. 

These workings are very irregular and include some unnecessary 

work.

The country rock is diorite. or hornblende gneiss, containing streaks 

of mica schist. The bodies of pegmatite cut the inclosing rocks irregularly. The main vein is as much as 15 feet thick, strikes 

N. 20° E., and has a westerly dip. It contains segregations of quartz, 

two veins of which are exposed in the first shaft made. The body of 

pegmatite cut in the crosscut tunnel is about 10 feet thick, and includes horses or streaks of mica schist. Only small crystals of mica 

were found in this vein. The mica obtained from the main vein has 

a slightly smoky color and part is specked. It has a good cleavage, 

and some of the small crystals seen were clean and sound. Goodsized sheets are reported to have been obtained during mining.

TERRY PROSPECT.

A mica prospect was opened on the old Terry place, about 6 miles 

west of Iva, by an open cut, 35 feet long, in the side of a knoll. Massive white quartz is abundant on the summit of the knoll and much 

mica in small sheets has been left around the pit.

McCONNELL PEOSPECT.

A prospect opened on the place of J. N. S. McConnell, 3f miles 

north of Anderson, yielded promising specimens of mica with 

beryl crystals of good color, reported to be nearly emeralds. When
286 MICA DEPOSITS OF THE UNITED STATES.

examined the workings consisted of a trench 45 feet long, 15 feet 

wide, and 5 feet deep, run N. 70° E., and a crosscut trench that 

entered it at the west end. The country rock is weathered to a 

dark reddish-brown sandy soil, and no outcrops were seen near the 

prospect. The soil has probably been formed by the weathering 

of a biotite or hornblende granite and carries small blocks of diorite. 

The pegmatite is not now exposed, but the dump contains kaolinized 

feldspar, blocks of massive white quartz, smoky and colorless quartz 

in rough crystals, weathered plates of mica 8 inches or less across, 

large dark-red garnets, black tourmaline, limonite pseudomorphs 

after pyrite, and black stains of manganese oxide. The mica remaining after the weathered parts are trimmed off is clear and of 

good quality. The principal workings are along the summit of a 

ridge extending north by west down to Little River. The deposits 

have been tested by pits for 75 yards S. 15° E. up the ridge. 

The deepest pit was probably not more than 15 feet deep, and most 

of the openings are partly filled. The country rock is mica gneiss, 

but its relations to the pegmatite were not visible. The pegmatite 

is at least 20 feet thick. Massive ledges or veins of the white quartz 

form part of the pegmatite. Only small sheets of mica were seen 

around the mine, but large crystals are reported to have been found. 

The mica is of a clear light rum color and of good quality.

WELBOEN PEOSPECT.

A prospect reported to be about 10 feet deep was opened several 

years ago on the land of W. C. Welborn, about 6 miles east-southeast 

of Pendleton, but has now been filled. The country rock at this 

place is badly weathered mica gneiss, which strikes N. 60° E. and 

dips 55° SE. Small beds of pegmatite exposed in the roadside cut 

the bedding nearly perpendicularly. Blocks of white quartz were 

left on the surface. So much scrap mica is mixed through the soil 

around the prospect as to indicate that the deposit is rich. It may 

have been abandoned because the mica is rather heavily specked, 

as at one time that variety was not in strong demand. Some of the 

mica has A structure but would yield good sheets from the parts 

between the A markings. A few rough sheets 8 inches in diameter 

were seen.

GREENVILLE COUNTY. 

WILLIMON MINE.

One of the largest mica mines in South Carolina is that of R. C. 

Willimon, 9 miles southeast of Greenville. This mine has been operated intermittently for many years and has recently been leased by 

J. E. Burleson, of Spruce Pine, N. C. The operations here have
SOUTH CAROLINA. 287

been fairly extensive, but none of the underground workings were 

accessible at the time of the examination. Openings have been 

made for 200 yards N. 60° E., and a few prospect pits, not in the 

same line, have been dug. The position of the numerous openings is 

shown in figure 83, and it is said that there was considerable drifting 

and stoping. The deepest shaft is more than 100 feet deep. The 

rocks are so soft that many of the workings have caved in, and in 

the endeavor to find new ground and avoid old workings many

FIGURE 83. Plan of Willimon mica mine, 9 miles southeast of Greenville, Greenville 

County, S. C. See text for explanation of numbers.

shafts have been made. The following observations were made at 

the openings shown by numbers in figure 83:

1. A shaft 25 feet deep in decomposed mica gneiss and pegmatite. The pegmatite is about 3 feet thick, strikes N. 60° E., and dips 75° NW. Mica In 

sheets 2 to 3 inches across.

2. Shaft 30 feet deep, partly caved in. Pegmatite 5 feet thick in decomposed 

kyanite-mica gneiss, both striking N. 60° E. and dipping 80° NW. Considerable 

small mica in dump.

3. Shaft 40 feet deep in decomposed mica and kyanite gneiss inclosing pegmatite.

4. Prospect trench; did not cut the vein.
288 MICA DEPOSITS OF THE UNITED STATES.

5 and 6. Old shafts partly filled by caving. Only small mica left on the 

dumps.

7. Rather large dumps of waste removed from 8; contains some decomposed 

porphyritic granite.

8 and 9. Extensive underground workings, now mostly caved in. Pegmatite 

inclosed in decomposed mica gneiss.

10. Two new shafts, 10 and 30 feet deep, in mica gneiss on northwest side of 

the pegmatite.

11. Shaft more than 30 feet deep. Bed clay near surface; decomposed pegmatite below. Small mica blocks of pegmatite and massive quartz on dump,

12. Old shaft in pegmatite.

13. New shaft 30 feet deep with water in bottom.

14. Old workings badly caved in. Much small mica on dumps.

15. Old shaft 20 feet or more deep, badly caved in. Small mica on dump.

16. Large pit or open cut on vein.

17. Large dumps of waste removed from 18.

18. Deep shaft, drifts, and stopes; badly caved in. Was equipped with stefini 

pump, hoist, etc. Much mica obtained from these workings.

19. Prospect pit; no pegmatite found in the decomposed mica gneiss.

20. Prospect pit in pegmatite. Small mica found.

A view of the workings northeast from the shafts at (10) is given 

in Plate XXIV, B (p. 260).

The country rock is composed of mica schist and gneiss, kyanitic 

in places, cut by porphyritic granite and pegmatite. All these rocks 

have been weathered to soft earth to a depth of at least 30 feet. 

Four veins of pegmatite have been tested, one of which has proved 

large and continuous. This vein is more than 10 feet thick in places 

and contains segregations or masses of quartz. The veins of pegmatite are approximately conformable with the inclosing rock, striking 

about N. 60°-65° E. and having vertical to high northwest dips.

Little could be learned of the quantity of mica the mine has produced or of the size of the better sheets. Possibly 25 tons of small 

sheet and scrap mica was lying around the workings. This mica 

could be screened and used for grinding. The small-sheet mica seen 

had a clear amber to rum color and good cleavage. Some of it was 

considerably ruled.

OCONEE COUNTY. 

LEROY PROSPECTS.

Several deposits of mica have been prospected on the G. W. Leroy 

place, 5 miles northeast of Seneca. The mining or prospecting here 

was done by Thaddeus Leroy, who owns other mica prospects on land 

adjoining on the west. Some of the smaller prospects were tested by 

a few days' work, and the mica obtained is said to have paid wages 

of over $3 a day for the work.

Other prospects for mica have been tested or are known on the 

properties of John Dyer, half a mile, and J. F. Smith, three-quarters 

of a mile south of Leroy's.
MICA DEPOSITS OF THE UNITED STATES. 289

SOUTH DAKOTA. 

GENERAL FEATURES.

The mica deposits of South Dakota have been worked intermittently for many years. According to C. C. O'Harra 77 the earliest 

exploration for mica was made in 1879, when the McMacken mine 

(later called the Crown) was opened. Between 1879 and 1884 this 

mine is reported to have yielded 45,000 pounds of cut mica, valued 

at $135,000. Other mines were opened soon after the McMacken, 

and in 1881 plates of mica measuring 4 by 10 inches were reported 

as coming from the La Barres mine,78 near Ouster. Other valuable 

deposits opened during this period were the New York, Lost Bonanza, and Climax. Between 1884 and 1899 mica mining was at a 

low ebb in South Dakota, and little more than assessment work was 

done. In 1889 and 1900 more active mining was resumed. In 1906 

the industry received a big impetus with the reopening of the New 

York, White Spar, and other mines by the Westinghouse Electric 

& Manufacturing Co. These mines were operated for several years 

on a large scale but are now all closed. Other mines have been 

worked since 1910 by the McBride Bros, for different companies, 

and these and a few small deposits have been the only producers 

since the Westinghouse mines were closed down, in 1911. During 

the years of largest production of mica in South Dakota that is, 

from 1907 to 1911 the annual output ranged from several hundred 

thousand to more than a million and a half pounds of rough sheet 

mica and from 300 to 1,000 tons of scrap mica.

Most of the mica deposits that have been tested are within a radius 

of 10 miles of Custer, in the southern part of the Black Hills. 

This area includes the better deposits of mica so far located, but 

other deposits occur 12 to 15 miles north of Custer, in the Keystone 

region, on the north side of Harney Peak. Several of the deposits 

were briefly examined in August, 1908, when the descriptions given 

below were prepared.

GEOLOGY OF THE BLACK HILLS.

The geology and mineral resources of the Black Hills have been 

described by many writers. Of the reports on geology, those of 

Newton and Jenny 79 and of Darton,80 taken together, furnish good

 "The mineral wealth of the Black Hills: South Dakota School of Mines Bull. No. 6, 

pp. 75-77, 1902.

'8 Eng. and Min. Jour., vol. 32, p. 44, 1881.

78 Newton, Henry, and Jcnney, W. P., Geology and resources of the Black Hills of 

Dakota: U. S. Geog. and Geol. Survey Rocky Mtn. Region, 1880.

60 Darton, N. H., Preliminary description of the geology and water resources of the 

southern Black Hills: U. S. Geol. Survey Twenty-first Ann. Rept., pt. 4, 1901; Geology 

and water resources of the northern portion of the Black Hills and adjoining regions 

in South Dakota and Wyoming: U. S. Geol. Survey Prof. Paper 65, 1909.
290 MICA DEPOSITS OF THE UNITED STATES.

descriptions. The mica resources have been treated in the reports of 

the South Dakota Geological Survey and have been mentioned in the 

annual reports on the mineral resources of the United States published by the United States Geological Survey. A booklet containing a geologic map, by Samuel Scott,81 of Ouster, S. Dak., serves as 

a useful guide to the general geology of the Black Hills.

The Black Hills form a group of mountains that rise to a maximum elevation, in Harney Peak, of 7,240 feet above the sea, or 3,000 

to 4,000 feet above the surrounding plains. They constitute an oval 

uplift about 125 miles long from north-northwest to south-southeast 

and 60 miles wide. The core of this uplift is composed of highly 

metamorphosed slates, gneisses, and schists of pre-Cambrian age and 

granitic intrusives. This core of ancient rocks is completely encircled by strata of later formations, which dip away from the core 

on all sides and were evidently once continuous over its top as a 

dome. The oldest of these strata is a conglomerate and sandstone 

formation of Cambrian age, called the Potsdam by Newton and 

Jenney and the Deadwood by Darton. The Deadwood formation 

is overlain by other formations, among which are limestone of Carboniferous age, red beds and shale of Triassic (?) and Jurassic age, 

Upper and Lower Cretaceous sandstones, shales, and limestones, and 

Tertiary " badland " formations. These formations crop out at successively greater distances from the central core of metamorphic 

rocks, and some of the outcrops form hogbacks with scarps toward 

the center of the uplift.

Newton and Jenney call attention to a marked difference between 

the metamorphic rocks of the northeastern part of the area and those 

of the southwestern part. Those of the northeastern part are less 

metamorphosed and more nearly like slates in texture and structure, 

whereas those of the southwestern part are highly metamorphic, 

micaceous, chloritic, hornblendic, and quartzitic gneisses and schists. 

Newton and Jenney call the gneisses and schists " Older Archean " 

and the slates " New Archean." In a report on the Cretaceous formation of the Black Hills,82 the northeastern metamorphic area is 

called Algonkian and the southwestern area Archean. Whatever 

may be the age of these formations, that in the southwestern part, in 

which the mica deposits occur, is composed of true gneisses and 

schists, in which the mashing has been extreme and the development 

of metamorphic minerals extensive. In comparing typical specimens of the slates and mica slates of the northeastern area with the 

gneisses and schists of the southwestern area, the writer was 

impressed with the extreme difference in the degree of metamorphism

81 Rocks, minerals, and other resources of the Black Hills.

n Ward, L. F., Jenney, W. P., Fontaine, W. M., and Knowlton, F. H., U. S. Geol. 

Survey Nineteenth Ann. Kept., pt. 2, pi. 53, 1899.
SOUTH DAKOTA. 291

they had undergone. Newton and Jenney state that granites occur 

only in the " Older Archean " rocks and that granitic pebbles were 

found in the Cambrian conglomerate overlying them. They therefore conclude that the granite is pre-Cambrian and older than the 

slate.

Sidney Paige,83 after a detailed study of the pre-Cambrian area, 

has concluded that the slates, schists, and gneisses composing the 

core of the hills are all of one age. All these rocks have undergone regional metamorphism, but those of the southern part of the 

hills have been further metamorphosed by the large intrusions of 

granite and pegmatite. The metamorphism of the rocks in the 

immediate region of the igneous intrusions has been extensive and 

has led to the uncertainties regarding the identity of rocks having 

appearances so diverse as those of the pre-Cambrian in the northern 

and southern parts of the Black Hills.

The granite formation of the Black Hills is most conspicuously 

seen around Harney Peak and southward to Custer. Other smaller 

bodies of granite and the pegmatite into which it appears to grade 

in some places occur in different parts of the highly metamorphosed 

area. Many of the masses of granite and pegmatite form prominent 

outcrops. Some of the granite outcrops assume on weathering characteristic columnar or needle-like forms, such as are seen in the 

Harney Peak region. (See PI. XXV, A, p. 261.) Many of the deposits of pegmatite form large sheetlike outcrops that stand prominently above the low ground or on the hillsides.

Much of the granite has a very coarse texture, and in some places 

it is difficult to decide whether to classify the rock as granite or 

pegmatite. The pegmatite occurs both in the metamorphic rocks 

and in the granite. The prevailing trend of the gneisses and schists 

and of many of the inclosed pegmatites in the region of Custer is 

northwest to north. The dip is more variable, though in the many 

localities noted it was to the southwest or vertical. The gneisses 

and schists are much folded in places and are to some extent crinkled 

with minor folds.

The mica-bearing pegmatites of the Black Hills exhibit a rather 

uniform mixture of feldspar and quartz, which in some places is 

very coarsely crystallized. In other pegmatites, noticed especially 

in connection with deposits of rose quartz, the minerals occur in 

large segregations. At Samuel Scott's Rose Quartz mine, 6% miles 

S. 50° E. of Custer, the pegmatite incloses a vein of quartz, part 

of it rose-colored, which is 6 to 15 feet thick and 10 to 30 feet high 

and extends for more than 100 yards. In the mica-bearing pegmatites examined the feldspars were chiefly orthoclase or microcline,

M U. S. Geol. Survey Geol. Atlas, Black Hills folio (In preparation).
292 MICA DEPOSITS OF THE UNITED STATES.

with some plagioclase, albite, and oligoclase. The mica is a variable 

constituent of the pegmatites.

A number of accessory minerals have been found in the pegmatites 

of the Black Hills. In several of the deposits north of Harney Peak 

cassiterite, large crystals of spodumene, amblygonite, columbite, and 

beryl have been found. In the mica deposits near Custer these minerals are rare. In nearly every one of the mines examined around 

Custer black tourmaline was found, and in many of them large 

crystals were abundant. J. A. Holmes 84 mentions this occurrence 

and contrasts it with the general scarcity of tourmaline in the tinbearing pegmatites north of Harney Peak. He also says that mica is 

apparently not found plentifully in commercial sizes in the pegmatite of the tin region. Holmes 85 estimates that in some parts of the 

New York mine mica forms 10 per cent of the whole body of pegmatite, but that in others it forms not more than 1 per cent. Figures 

furnished by Joseph Pyne, the superintendent, show that the rough 

mica obtained along the walls of the pegmatite (the only part of it 

worked for mica in this mine) amounts to 6 or 7 per cent of the rock. 

The interior of the pegmatite at this mine carries very little mica, 

about one-half of 1 per cent; this estimate would give about 2.5 per 

cent of mica in the whole mass of pegmatite. The mica-bearing 

pegmatites around Custer tend to have an evenly granular texture 

or irregular segregation of mineral masses rather than a banded 

structure. In much of the rock, however, there is a rough banded 

arrangement in the segregation of the mica crystals along one or 

both walls. This structure' does not resemble a vein so much as the 

bands of a single mineral, such as quartz or feldspar. A few of the 

crystals of feldspar and irregular masses of quartz are several feet 

across. Some of the bodies of pegmatite occur in regular sheets, 

whose outcrops can be traced for several hundred yards; others are 

typically lenticular. Some lie parallel with the schistosity of the 

inclosing rock; others cut across the rock. In their general features 

those around Custer resemble dikes, the veinlike type being rare.

OUSTER COUNTY. 

NEW YORK MINE.

The New York mine, called mine No. 1, of the Westinghouse 

Co., is 5| miles southwest of Custer, between Hay and Four-mile 

creeks. - The mine is in a small, prominent hogback-like knob 700 

feet long and 250 feet wide. (See PI. XXV, 5, p. 261.) This knob 

is nearly 200 feet higher than the level of Hay Creek, on the south84 Mineral Resources of the United States, 1898, Mica: U." S. Geol. Survey Twentieth 

Ann. Kept, pt. 6 (continued), p. 699, 1899. 

88 Idem, p. 693.
SOUTH DAKOTA. 293

east, and about 100 feet higher than the gentle slope from its base 

to the valley of Hay Creek.

The earlier work at the New York mine consisted of open cuts, 

inclines, and stopes, which in one place extended from the surface 

nearly to the 100-foot level. The workings of the company have 

been systematic, and at the time of the examination consisted of a 

vertical shaft to the 200-foot level, at the bottom of which was a 

16-foot sump, and drifts with stopes on the 50-foot, 100-foot, and 

200-foot levels. According to Jesse Simmons 86 the shaft had been 

carried to a depth of 315 feet at the time of his visit, a few years 

later. The mine was equipped with a 400-horsepower boiler and 

engine, of Westinghouse make. Power was transmitted electrically 

from two 150-kilowatt generators. The mine was lighted with incandescent electric lights and the camp with arc lamps. The hoist, 

grinding plant, and shop were also operated by electric power. Air 

drills were used throughout the mine.

The country rock is biotite gneiss and schist, striking northwest 

and dipping about 50° SW. The pegmatite is approximately conformable with the inclosing gneiss. The contact of the two is 

sharp, though there are gentle rolls along the strike. The pegmatite has a thickness "across the dip of about 30 feet at the surface, 

25 feet on the 100-foot level, and 28 feet on the 200-foot level. The 

mica occurs along each wall of the pegmatite in two streaks or 

" veins " from 1 foot to 8 feet thick. The interior of the pegmatite 

is nearly barren of mica or is too poor in it to pay for working. 

Although the streaks vary in thickness and richness they are unusually regular for mica. Through the greater part of the mine 

that was opened before the time it was visited the veins were sufficiently rich to pay for working, and in places the mica was very 

abundant. Many of the crystals of mica occur in flattened or 

tabular blocks that lie perpendicular to the walls of the pegmatite, 

though they have no other definite orientation. The crystals generally range from 2 to 8 inches in diameter and from 1 inch to 5 

inches in thickness. Crystals a foot across are not rare, and some 

measure a yard.

Figure 84 represents a generalized cross section of the pegmatite 

" veins " and workings at the New York mine. The first operations 

at this mine were influenced largely by the position of the outcrop 

of the pegmatite, which forms the top and southwest side of the 

knob in which the mine is located.

The footwall of the pegmatite crops out along the top of the 

.knob, and the hanging wall lies near the surface along the south-

« Mica in the Black Hills of South Dakota: Min. World, p. 221, 1910. 

111375 23 20
294 MICA DEPOSITS OF THE UNITED STATES.

west side. The relations are shown in Plate XXVI, A, in which 

the workings on the footwall are seen on the summit of the knob 

and those along the hanging wall on the left side.

Many small openings have been made on the outcrop, and drifts 

have been run to the northwest on each " vein " on the 50-foot level. 

The entrance to the 50-foot level is made from an open cut on the 

outcrop of the vein about 50 feet below the top of the hill. The drift 

on the hanging-wall " vein " was run about 130 feet and a small 

amount of stoping was done. The " vein " was rich in mica to a 

point within 15 feet of the end of this drift, but at the end the mica 

content was small. A crosscut connects this drift with the footwall 

" vein," the drift on which was carried about 250 feet to the northwest. For 100 feet of this length the " vein " had been stoped out, 

to the top of the knob, 50 feet above, and beyond this stretch good

ZOO-ft. level<

Mica gneiss

FIGDRB 84. Generalized cross section of No. 1 or New York mica mine, near Custer,

S. Dak.

vein matter was held ready for stoping. At the southeast limit of 

the surface workings, about 200 feet from the shaft, the .pegmatite 

contains a large quantity of black tourmaline .in crystals ranging in 

diameter from 1 inch to several inches, some of them many feet long. 

The mica content of the pegmatite is very small at this point.

The shaft starts southwest of the pegmatite and cuts through it 

between the 100-foot and 200-foot levels. Only the hanging wall 

had been worked on the 100-foot level at the time of the examination. 

This level is connected with the shaft to the southwest by a short 

crosscut. Drifts have been run from the crosscut about 300 feet 

northwest and 250 feet southeast. The vein was stoped out to the 

50-foot level for 200 feet -northwestward and work was being carried farther. The pegmatite at the end of this drift was very poor 

in mica and was composed of large crystals of feldspar, massive
SOUTH DAKOTA. 295

quartz, and black tourmaline. The drift was to be carried farther 

in search of richer " vein " matter. In the southeast drift much of: 

the " vein " has been stoped out to the surface for about 240 feet 

from the crosscut. At this point the vein becomes poor in mica and 

carries abundant black tourmaline like that seen in the surface workings. Some of the tourmaline crystals measure 10 inches in diameter. They do not appear to have any definite position relative to 

the wall of the pegmatite. The vein was rich nearly 'to the end of 

ench clrift and in the large stopes. The strike of the contact of the 

vein is nearly straight throughout the length of the drifts except at 

a point a few feet southeast of the crosscut, where the mica schist 

wall elbows out into the pegmatite for several feet across the strike 

of the vein.

A room was made southeast of the shaft on the 200-foot level for 

an electric pump, for loading cars on the cage, and for other purposes. 

A crosscut run 10 feet from this room to the southwest cuts the footwall of the pegmatite, which is about 28 feet thick. Mica was seen 

in the foot-wall " vein " here, but it had not been developed at the 

time the mine was visited. Drifts were started to the northwest and 

to the southeast on the hanging-wall " vein " and when seen were 

each in about 20 feet. These drifts have since been carried farther. 

At the end of the southeast drift an irregularity in the " vein " or a 

fault was encountered. The vein matter seen in the 40 feet of drift 

on the 200-foot level was very rich and contained considerable mica 

in large blocks. Several blocks more than a foot across and a large 

number of smaller blocks were seen in the walls.

The richness of a part of the pegmatite in mica is shown in Plate 

XXVI, #, which is a view on the 200-foot level a few feet southeast 

of the crosscut from the shaft. Records kept by Mr. Pyne, the 

superintendent of the mine, showed an average of 60 pounds of 

rough mica every square foot of the surface of the "vein." The 

thickness of the "veins" averaged about 5£ feet. If a cubic foot 

of pegmatite weighs 163 pounds the rough mica obtained averages 

about 6.6 per cent of the vein matter.

WHITE SPAR MINE.

The White Spar or No. 2 mine of the Westinghouse Co. is If 

miles S. 40° W. of Ouster. This mine was equipped with two 

45-horsepower boilers, a bucket hoist that served also as a pump, 

electric lights, air drills, mine cars, and tracks. The surface equipment and appearance of the mine are shown in Plate XXVII, A. 

The mine was opened irregularly from the surface by open cuts, 

inclines, and drifts to a depth in places of nearly 40 feet. The 

workings of the Westinghouse Co. consisted of a vertical shaft
296 MICA DEPOSITS OF THE UNITED STATES.

110 feet deep, 10 feet at the bottom serving as a sump, a crosscut 

and drift on the " vein " at the 100-foot level, and drifts and stopes 

on the 50-foot level. The shaft was sunk in the " vein " for 50 feet 

from the surface down and then passed through the footwall into 

the country rock.

A general plan of the workings of the Westinghouse Co. on the 

50-foot and 100-foot levels, as seen in August, 1908, is given in 

figure 85. The "vein" is about 40 feet thick at its outcrop, 2£ feet 

thick at the 50-foot level, and 18 to 20 feet thick at the 100-foot 

level.

The country rock is biotite gneiss containing prominent highly 

schistose beds, some of which are much crumpled. The gneiss 

strikes N. 30°-60° W. and dips about 45° SW., though the dip is 

variable from place to place. The course of the " vein " of pegmatite is roughly conformable with the 

schistosity of the 

gneiss, though it is 

at some places very 

irregular. On the 

50-foot level the pegmatite pinches out at 

a distance of 40 feet 

southeast of the shaft 

and the gneiss folds 

around it, as indicated in figure 85. 

In places the contact of the pegmatite 

and gneiss is straight, though it is generally somewhat curved and 

rolling.

The mica is irregularly distributed through the pegmatite. At one 

place southeast of the shaft on the 50-foot level nearly half the 

"vein " was mica, which was in blocks of various sizes, some of them 

a foot in diameter. The edge of one block of mica, or of several 

blocks closely joined together, which projected from the floor of the 

room southeast of the shaft, was nearly 5 feet long and 2 to 12 inches 

thick. The crystals of mica appear to have no definite orientation 

but are mixed with the quartz and feldspar of the pegmatite. The 

feldspar is coarsely crystallized; a crystal of orthoclase 4 feet through 

was seen in the wall. Quartz occurs in the pegmatite in large, irregular masses several feet across. Other minerals found are black tourmaline, garnet, and white to pale-greenish beryl. One broken crystal 

of beryl 6 inches in diameter and 8 inches long was seen. The mica 

is suitable for electric work, and some of it could be used for glazing.

Pegmatite removed 

on SO^foot level

Pegmatite removed 

on 100-foot level

gneiss

FIGURE 85. Plan of No. 2 or White Spar mica mine, near 

Custer, S. Dak.
SOUTH DAKOTA. '297

Part of it contains flattened garnets between the laminae and tourmaline, which has grown through the crystals at different angles.

Ledges of pegmatite are plentiful in the neighborhood, and two 

other large ones crop out 50 to 80 feet southwest of the main ledge. 

The Westin'ghouse Co. intends to continue the crosscut on the 100- 

foot level to cut one of these ledges.

NO. 4 MINE.

Mica mine No. 4 of the Westinghouse Co. is 5 miles N. 15° E. of 

Custer, in a ridge between two branches of the headwaters of French 

Creek. The mine is about 300 feet higher than the valley on the 

northwest. The greater part of the work was done by operators who 

preceded the Westinghouse Co., which stopped work temporarily 

after doing a small amount. Openings have been made at two places, 

one on a small knob, the other about 200 yards S. 65° E. of it. These 

openings are apparently on different bodies of pegmatite. The ledge 

of pegmatite running through the knob strikes N. 15° W. and dips 

60° E. The ledge at the other opening is complex and its direction 

was not determined. Between the two openings a strong ledge of 

pegmatite crops out with a strike of N. 65° W. and a dip of 40° N. 

This ledge extends to that on the knob, by which it seems to be cut 

off. Other bodies of pegmatite that show similar variations in direction occur in the vicinity.

The body of pegmatite that cuts through the knob is about 25 feet 

thick and has been traced southward along the knob for nearly 100 

yards. It is composed of large, irregular masses of feldspar and pale 

rose-colored quartz, variable quantities of mica and black tourmaline, and small quantities of biotite mica, apatite, and garnet. The 

mica seems to occur principally along the hanging wall and has been 

worked by an open cut on the north end of the knob. Many crystals 

of mica project from the pegmatite for some distance along the outcrop.

At the other opening a tunnel was run N. 60° W. from an open cut. 

At the entrance to this tunnel biotite gneiss was exposed in the floor 

and on one side. Its foliation strikes N. 65° W. and dips about 30° N. 

In the open cut the pegmatite dips in the opposite direction. The 

mica found in this opening seems to have been plentiful and to have 

been of fairly large size.

CROWN MINE.

The Crown mica mine of the Chicago Mica Co. is 2| miles .northwest of Custer. It has been worked by several open cuts the main 

one about 130 feet long and 25 feet deep and wide a 20-foot incline 

from the bottom of the cut, a 100-foot shaft with a crosscut to the 

'"vein." a drift, and a stope. The stope reaches about half way to
298 MICA DEPOSITS OF THE UNITED STATES.

the bottom of the incline. The mine has been equipped with a 40- 

horsepower boiler, a hoisting engine, an air-drill compressor, three 

pumps, a storage and loading house, and an office.

The country rock is muscovite-biotite gneiss, which has straight slaty 

cleavage in some places and a plicated structure in others, especially 

near the bodies of pegmatite. The schistosity of the gneiss strikes 

about N. 35° W. and has a variable dip. The body of pegmatite

is about 10 feet thick 

and is in part at least 

conformable with the 

schistosity of the gneiss; 

It has the form of an 

anticlinal fold whose 

axis pitches southeastward at. an angle of 

about 10° or 15° down 

the slope of a low ridge. 

At the northwest end 

of the open cut the crest 

of folded pegmatite 

forms a blanket over the 

top of a small hill and 

has been worked for a 

width of 40 feet by a 

shallow open cut. The 

northeastern limb of the 

fold has been followed 

down on a dip of about 

40° by a 20-foot incline. Sufficient development work has not 

been done to determine 

the dip of the other limb 

of the fold to the southwest. The open cut has 

been made along the axis 

of the fold and cuts 

through the pegmatite. 

While assessment work was being done an 18-inch pegmatite dike 

was encountered about 50 feet northeast of the main body. This 

pegmatite failed to reach as far as the present surface by several 

feet. It is conformable with the strike of the inclosing gneiss, which 

it has split apart and crushed in the direction of its intrusion. The 

mica gneiss between this small dike and the main one is somewhat 

plicated and has been folded into a syncline. Figure 86 gives at a

Mica gneiss

B

FIGURE 86. Crown mica mine, near Custer, S. Dak. 

A, Generalized cross section; B, sketch show,ing 

relation of pegmatite dike to inclosing gneiss.
SOUTH DAKOTA. 299

a generalized cross section of the formation and development work 

at the mine looking northwest, and at 6 is a sketch of the small dike 

and its relation to the inclosing gneiss as seen from the northwest. 

Plate XXVII, #, is a reproduction of a photograph of the same small 

dike showing its relation to the gneiss. The main body of pegmatite contains inclusions or horses of mica gneiss in long streaks that lie parallel 

to the walls and that range from a few inches to 3 feet in thickness.

The pegmatite remaining in the mine contains much small mica. 

The small dike does not carry merchantable mica so far as it 

has been opened, but it illustrates the method of intrusion of a pegmatite dike and the way in which such dikes, and consequently 

some mica "veins," pinch out abruptly.

The Crown mine was later acquired by the Westinghouse Co. and 

was worked during the last year or two that the company operated 

in the Black Hills.

c,if f --"^"'^^ ^_^ 4%r jf^F

V- '." -.,/tao-ft.shaft

 Pegmatite

B

FIGURE 87. Plan (A) and cross section (B) of Great Northern or Old Mike mica mine,

near Custer, S. Dak.

OLD MIKE MINE.

The Old Mike mica mine, now called the Great Northern, is 3f 

miles N. 20° W. of Custer, on the north end of the ridge that extends 

northward from Buckhorn Mountain. The pegmatite at this mine 

forms a cliff which faces northeastward and rises about 50 feet 

above the steep slope at its base. Other cliffs rise back of and 

above this one, to the southwest. The mine has been opened by a 

shaft 80 feet deep, a crosscut or adit 120 feet long, and a drift with 

stopes on the vein. (See fig. 87.) Some work has been done at the
300 MICA DEPOSITS OF THE UNITED STATES.

base of the cliff. The country rock is muscovite-biotite schist, which 

strikes nearly east and has a northerly dip. The body of pegmatite 

cuts across the schist with a strike of N. 65° W. and a vertical dip. 

It is 10 to 15 feet thick in the drift and has irregular curving walls. 

The mica is distributed irregularly through the pegmatite, and at 

some places where the pegmatite bulges out into the schist it is 

abundant. Here and there the pegmatite is fine grained and barren 

of merchantable mica. Mica is exposed in the face of the cliff, where 

a little work has been done. Most of the work in the cliff has 

been done to obtain columbite and cassiterite. Masses and crystals 

of columbite weighing several pounds have been obtained alongside of and in a streak of quartz in the pegmatite cliff. Crystals of 

brownish to black cassiterite occur in places through the finergrained parts of the pegmatite, and boulders of tin-bearing pegmatite lie on the slope of the mountain below the mine. The mica 

from this mine has a rum color and appears to be clearer than 

that from many of the other mines in South Dakota.

FIEESTONE MINE.

The Firestone mica mine is 4f miles S. 20° W. of Custer. It has 

been opened by a crosscut run through the schist and the barren part 

of the pegmatite, an open cut 20 feet deep, and an incline on the 

" vein." The incline was reported to be 75 feet deep and has a 30- 

foot drift to the northeast at the 20-foot level, below which it is 

filled with water. The country rock is muscovite-biotite schist 

striking N. 25° E. and dipping 60° NW. The pegmatite is about 

15 feet thick and is conformable with the inclosing rock. A few 

thin sheets or partings of schist are included in the pegmatite and 

lie parallel with its walls. Near the outcrop on the southwest 

side of the open cut, part way down the incline, the streak of mica 

lies along the hanging wall and is about 1 foot thick. In the northeast face of the cut the streak is in the pegmatite and is about 4 feet 

thick. The contact of the pegmatite and gneiss in the northeast 

face of the open cut is shown in Plate XXVIII, A. This part of 

the pegmatite contains little mica. In the drift also the " vein" 

is in the body of the pegmatite and is several feet thick. Mica seems 

to be plentiful in parts of the " vein," and some crystals several 

inches in diameter were seen. The feldspar and quartz of the pegmatite occur in irregular masses 2 or 3 feet across. Some of the 

quartz has a pale-rose color.

LOST BONANZA MINE.

The Lost Bonanza mica mine is If miles due north of Custer, on 

the east end of Buckhorn Mountain. The pegmatite cuts through 

a small knob with a strike of N. 80° W. and a dip of 40° S. and is
U. S. GEOLOGICAL, SURVEY BULLETIN 740 PLATE XXVI

A. VIEW NORTHWARD ALONG PEdMATlTIC OUTCROP AT NEW YORK MICA MINE, 

NEAR CUSTER, S. DAK.

B. CRYSTALS OF MICA IN PKfJMATITE AND BLASTED LOOSE ON 200-FOOT LEVEL 

OF NEW YORK MICA MINE, NEAR CUSTER, S. DAK.
U. S. GEOLOGICAL SURVEY BULLETIN T40 PLATE XXVII

A. VIEW NORTHWARD TOWARD ENGINE AM) S1IAKT HOUSE OF WHITE SPAR 

MICA MINE, NEAR CUSTER, S. DAK.

B. END ()! IVIItliSION OK SMALL DIKE OF PEGMATITE AT CROWN MICA MINE, 

NEAR CUSTER, S. DAK.
U. S. GEOLOGICAL SURVEY BULLETIN 740 PLATE XXVIII

A. CONTACT OF PEGMATITE AND GNEISS IN NORTHEAST FACE OF OPEN CUT 

AT FIRESTONE MICA MINE, NEAR CUSTER, S. DAK.

B. LARGE CRYSTALS OF BLACK TOURMALINE EXPOSED IN SMALL CUT ALONG 

WALL OF PEGMATITE AT PHILIP GEERING'S MICA PROSPECT, NEAR CUSTER, 

S. DAK.
U. S. (IICOLOCK'AL Sl'RVEY BULLETIN 740 PLATE XXIX

A. SURFACE EQUIPMENT OF CHAMPION NO. 2 MIC.A MINK, AMELIA COUNTY, VA.

B. INTKKIOK OF MICA-TKIMMING HOUSE OF 1UDGEWAY MICA CO., 

KIDGEWAY, VA.
SOUTH DAKOTA. 301

conformable with the inclosing muscovite-biotite gneiss. The mine 

has been worked by an open cut, an incline, and a tunnel more than 

200 feet long, with stopes. The tunnel is about 40 feet lower than 

the top of the hill, and nearly all of the " vein " between the two 

has been worked out. The outcrop of the pegmatite is exposed for 

nearly 100 yards along the strike. The pegmatite ranges in thickness 

from 15 inches to more than 8 feet. At the east end of the open 

cut a part of the pegmatite is nearly barren of mica and carries 

crystals of black tourmaline, some of which are 10 inches in 

diameter.

CLIMAX MINE.

The Climax mica mine is 2 miles due east of Custer. It has been 

opened by three shafts, not more than 50 feet apart, connected by 

drifts. One of these shafts was more than 60 feet deep. The country rock is schistose biotite gneiss, striking northeastward and having a high dip, and the pegmatite is approximately conformable 

with the schistosity. As seen in the outcrop, the pegmatite is about 

20 feet thick and carries mica in pockets containing crystals of many 

sizes, some of them several inches in diameter. Regular streaks of 

mica may have been found in the workings. The mica is of good 

quality and has a wine-yellow color. Black tourmaline and smoky 

and opalescent quartz occur in the pegmatite.

About 100 yards northwest of the old workings another body of 

pegmatite, 2£ to, 4 feet thick, has been opened by a shaft, drifts, and 

a small open cut. This " vein " is conformable with the inclosing 

biotite schist-gneiss, which strikes N. 45° W. and has a vertical dip. 

The mica is scattered through the pegmatite.

ST. LOUIS MINE.

The mine of the St. Louis Mica Co. is on the south side of French 

Creek, 4| miles S. 65° E. of Custer. The outcrop of pegmatite at 

this mine forms a bare floor, nearly 100 feet square, on the gentle 

slope of a hill. It contains several small streaks of mica gneiss, 

which strike N. 70° W. and dip 65° SW. Streaks of mica that contain numerous small crystals occur in the pegmatite, and two of them 

strike northeast and have a vertical dip. The work done here consists of shafts and several open cuts, now badly caved. Large blocks 

of mica are said to have been found.

GALESBURG MINE. \

The mine of the Galesburg Mica Co. is across French Creek from 

the St. Louis mine, in a sharp spur that rises from the bottom land 

of the creek, 4£ miles S. 70° E. of Custer. The spur is a hogback 

formed by the outcrop of a ledge of hard pegmatite, which strikes
302 MICA DEPOSITS OF THE UNITED STATES.

about N. 70° W., dips 45° N., and is more than 25 feet across. The 

hanging wall is biotite gneiss. The footwall and the full thickness 

of the pegmatite are not exposed. Next to the hanging wall is the 

" vein," the streak rich in mica, from 6 inches to 2 feet or more thick; 

next 10 to 15 feet of ordinary pegmatitic material; next a streak of 

massive quartz 6 to 10 feet thick; and then more pegmatite, containing rosettes of feldspar, in part at least albite. Black tourmaline 

occurs through the pegmatite, as usual.

PHILIP GEERING PROSPECT.

The Philip Geering prospect is 2f miles S. 25° W. of Ouster, on 

the southwest side of a prominent outcrop of pegmatite, which is 

about 35 feet across and stands 25 feet above the level country around 

it. The country rock is mica gneiss and, with the inclosed pegmatite, 

strikes N. 25° W. and dips about 45° SW. An interesting feature 

at this prospect is the" abundance of crystals of black tourmaline in 

the pegmatite. This occurrence of tourmaline-bearing pegmatite is 

shown in Plate XXVIII, B. These crystals range.from 1 inch to 6 

inches in diameter and compose nearly 50 per cent of the pegmatite 

in an area of 40 square feet. They apparently lie nearly normal to 

the wall of the pegmatite. Little mica was seen in the pegmatite, 

and it was not learned whether a good pocket had been encountered.

WYOMING LODE.

The Wyoming mica lode, owned by F. T. Peterson, is 5| miles 

S. 15° W. of Ouster. Pegmatite or pegmatitic granite forms a large 

part of the country rock at this prospect. Little mica schist is 

exposed, but what was seen occurs in streaks in the pegmatite and 

has a north by west strike and a southwest dip. The mica was 

found in a pocket or streak at one place; the greater part of the 

pegmatite in the outcrop is rather fine grained and carries only small 

mica. The mica obtained from the prospect has a rich rum color. 

Pink orthoclase, some containing graphic intergrowths of quartz, 

is exposed in the pit in masses several feet across. Black tourmaline 

and some pale rose-colored quartz are also found.

TEXAS. 

GENERAL FEATURES.

A glance at a geologic map of Texas shows two widely separated 

areas of pre-Cambrian rocks in which mica deposits might be found, 

one in Llano and Mason counties, in central Texas, and the other, 

which consists of two districts, in Culberson and El Paso counties, 

in western Texas. Prospects have been found in both areas.
TEXAS. 303

CULBEKSON COUNTY. 

TEXAS MICA CO.'S MINE.

Outcrops of mica were discovered in the Van Horn Mountains, in 

Culberson County (formerly El Paso County), between 1890 and 

1893, by Ben Kraus, of Pecos. The deposits lay idle until 1910, 

 when they were located by the Texas Mica Co., of Pecos, which purchased two sections of land from the State. The prospects lie on 

the west side of the Van Horn Mountains,.about 15 miles S. 20° W. 

of Van Horn. Van Horn is on the Texas & Pacific Railway, but 

the nearest railroad station is Dalberg, on the Southern Pacific line, 

about 9 miles northwest of the mine. The dirt road to Van Horn 

crosses the railroad about 6 miles north of the mine.

The mining developments are not extensive and at the time of 

the examination in 1913 consisted of two open cuts on the principal 

deposit and several smaller workings elsewhere. Trails and roads 

have been built from the camp to some of the prospects. A small 

grinding mill was erected for experimental work with some of the 

products mined. The mill is operated by an 18-horsepower gasoline 

engine, which also furnishes power for an air compressor and drill. 

The company has been interested in the development of two products, mica and micaceous rock suitable for giving a " micolithic " 

finish to cement and other structural material.

The Van Horn Mountains consist of a main range more than 15 

miles long with a scarp on the east, broken plateaus and ridges in 

the middle, and a less prominent range on the west. This smaller 

western range trends west of north, diverging from the main mass 

of the mountains, and sinks into the surrounding basin or plains 

a few miles north of the mica deposits. These deposits occur in 

the rough hills formed by valleys and eroded surfaces of the west 

range of the mountains. Most of the hill slopes are steep, in places 

breaking into rocky cliffs. The elevations near the deposits range 

from about 4,200 feet above sea level at the camp to more than 5,000 

feet at the north end of the property. The Van Horn Mountains 

are higher, reaching an elevation of 5,622 feet in the Van Horn 

Peaks, 2 miles east of the mica prospects.

The region is a typical desert and has the characteristic desert 

vegetation, including sagebrush and several species of cactus. 

Water for general camp use is caught during rains in a natural 

cistern or reservoir in a drawi about 200 j'ards east of the camp. 

Drinking water is hauled from a well about 1£ miles west of the 

camp.

The mica deposits occur in an area of pre-Cambrian crystalline 

rocks, which are exposed by the erosion of overlying sedimentary 

formations. Most of the adjacent sedimentary rock is rather heavy
304 MICA DEPOSITS OF TSE UNITED STATES.

bedded gray limestone, cherty in places, including a little limy shale, 

and is probably of Carboniferous (Pennsylvanian) age. An area of 

such rock in about the proper position for correlation, in the south 

end of the Carrizo Mountains, 8 miles north of the mica prospects, 

has been mapped as the Hueco formation by G. B. Richardson.87

The crystalline rocks consist of quartz-mica gneisses and schists, 

biotite schist, hornblende schist, and pegmatite. The quartz-mica 

gneisses and schists are composed chiefly of quartz, muscovite, biotite, 

and feldspar in variable quantities. They range from fine to 

medium grained and from light to dark gray according to the 

proportion of biotite they contain. Some of the outcrops have 

been made red and reddish brown by iron oxide. The biotite schist 

is a black, strongly laminated rock composed of coarse lustrous 

scales of biotite and small quantities of quartz and feldspar. The 

hornblende schist is a medium-grained greenish-black foliated rock, 

in which hornblende is a prominent constituent. At one place it 

is highly garnetiferous and contains crystals of garnet as much as 

half an inch in diameter. The pegmatite is prevailingly reddish 

and exhibits many of the irregularities of texture common to that 

rock. In most of the outcrops it is composed chiefly of feldspar 

and quartz but carries small quantities of mica. At some places 

mica is abundant. Most of the feldspar is reddish orthoclase or 

microcline, which occurs in small grains mixed with quartz, with 

or without mica, in typical granite texture, as graphic granite, and 

at some places in crystals measuring more than 2 feet in thickness. 

The quartz occurs also in irregular gray to white masses or segregations ranging in thickness from 1 inch to 5 feet. These masses 

of quartz are apparently scattered at random through the pegmatite. Most of the mica in the pegmatite is muscovite. It ranges 

from small scales to crystals a foot across. The crystals of mica 

occupy no regular position in the rock and vary greatly in abundance 

in different bodies of pegmatite and in different parts of the same 

body.

The crystalline rocks outcrop in an irregular-shaped area about 2 

miles long from north to south and a little more than half a mile 

wide. They have been complexly folded, as shown by the dip and 

strike marks in figure 88. These pre-Cambrian gneisses and schists 

have been cut by pegmatite both parallel to and across their schistosity. The pegmatite, however, does not cut the surrounding limestones, which overlie the crystalline rocks unconformably and dip 

away from the area on all sides at varying angles. The structure 

is that of an elongated dome from which the overlying sedimentary

87 Notes on northern border of the Chispa quadrangle, made during areal mapping of 

the Van Horn quadrangle.
TEXAS. 305

beds have been eroded, exposing the core of underlying crystalline 

rocks.

The mica of value as sheet mica and for grinding into pure products is found in pegmatite, which is abundant in the area of crystalline rocks and occurs in ledges and streaks ranging in width from 

a few inches to more than 100 feet. Sheet mica of promise has been 

found in only a 

few of these deposits. The principal working is 

on the east side 

of a draw about 

150 yards from 

the camp. It 

consists of two 

open cuts in a 

steep hillside. 

The larger cut is 

about 65 feet long 

from north to 

south and 5 to 20 

feet deep. The 

other opening, a 

crosscut trench, 

lies a few feet to 

the northwest 

and is about 35 

feet long and 15 

feet deep at its 

inner end. A 

view of the main 

open cut from the 

south is given in 

Plate IX, -R (p. 

62). The rocks 

around this cut

EXPLANATION

Mica prospect Strike and dip Pre-Cambrian Limestone and 

gneiss and schist other sedimeiuary 

with pegmatite rocks

are gneiss and FIGURE 88. Sketch of Texas Mica Co.'s claims,. 15 miles southDe<rmitite The west of Van Horn, Culberson County, Tex., showing topog-

,..*?' ' raphy and geology.

hills capped by

sedimentary rocks are in the background. These workings are on 

a large pegmatite dike having a northerly strike. The west wall 

of the pegmatite is not exposed, but on the east there is a rather 

fine grained red gneiss, composed of quartz, feldspar, biotite, and 

muscovite. The pegmatite incloses horses or streaks of both hornblende and quartz-mica schists parallel with its own strike.
306 MICA DEPOSITS OF THE UNITED STATES.

The mica was richest in an irregular streak developed by the 

largest open cut.- Several crystals are commonly found near together, scattered through nearly barren pegmatite at intervals of a 

few feet. From 4 to 5 tons of mica were taken from this cut. 

Much of the mica is small, but some seen in the storage house would 

trim into sheets 4 by 6 inches. The better crystals are firm and 

split fairly well. Most of the sheet mica mined would be punched 

into washers and cut into small sheets. The mica has a greenishbrown color in sheets one-sixteenth of an inch thick. Most of it is 

slightly specked and some is rather strongly specked with magnetite* 

Some of the larger mica crystals seen had been badly crushed and 

ruled. Others were wedge shaped or showed A markings.'

In two of the other prospects good sound mica in small crystals 

was observed. Only a little work had been done on these prospects.

At several places on the property the crystalline rocks have a 

composition which makes them useful, when ground and properly 

mixed with other ingredients, for giving a natural-rock finish 

("micolithic" finish) to cement and other construction material. 

The special rock used in the different mixtures varies with the effect 

desired. Several kinds of the quartz-biotite-muscovite schist and 

gneiss have been ground for this purpose. A large body of coarsebiotite schist supplies an abundance of black mica with which to 

vary the tone of the " micolithic " finish. This biotite schist occurs 

as a bed in contact with pegmatite. Several feet from the contact 

it is even-grained, finely laminated schist, composed largely of biotite 

in plates or scales as much as an eighth of an inch across. Within 

3 feet of the pegmatite the biotite scales are coarse, ranging in diameter from a sixteenth to more than half an inch. They are bunched 

at all angles, and the rock shows little schistosity. This rock may 

be called massive biotite.

MASON COUNTY.

A little mica has been found in Mason County. The only valuable 

specimen seen was an irregular-shaped sheet measuring 3 by 5 inches,, 

sent to the United States Geological Survey in 1914 by C. E. Lymanr 

of Minneapolis, Minn. This specimen came from the northwestern 

part of Mason County. It has a fine flat cleavage but is rather 

heavily specked with minute, thin brown to black flakes of magnetite 

between the laminae.

UTAH.

A little excitement was caused by the opening of a mica prospect 

near the head of City Creek, above Salt Lake City, Utah, in 1897.88 

Crystals 8 inches across were reported to have been found.

M Eng. and Min. Jour., vol. 64, p. 589, 1897.
VIRGINIA. , 307 

VERMONT.

Mica deposits have been reported in Vermont, but the only deposit 

of which there is any record in the United States Geological Survey 

is that on the land of A. L. Stone, 2 miles north of Chester, Windsor 

County.

VIRGINIA.

GENERAL FEATURES.

Mica mining began in Virginia about the same time as in North 

Carolina. T. L. Watson 89 states that the mines near Hewlett, Hanover County, were the first ones operated. Work was started there 

in 1867 and was continued for four years. The next work was probably done in Amelia County, where, according to Watson, the Jefferson mine was opened in 1873. The Berry, Pinchbeck, Rutherfoord, and Winston mines, near Amelia, and the Schlegal mine, near 

Jetersville, were started soon afterward.

The Virginia mica mines, like those of other States, have been 

operated intermittently, a few having been worked at four or five 

times. Some of the mines have been equipped with good machinery 

and plants for the preparation of the mica, but many of them are 

without these advantages. Trimming houses have been erected at 

some of the mines, and a few mica-grinding mills have also been, 

added to the equipment. These small mills have been destroyed or 

have been idle most of the time, and the bulk of the scrap mica from 

the Virginia mines is treated by the Richmond Mica Co.

Mica deposits have also been worked in Amherst, Bedford, Charlotte, Franklin,-Goochland, Henry, Pittsylvania, and Prince Edward 

counties. Indications of mica are reported by Watson also in Buckingham, Caroline, Cumberland, Powhatan, and Spottsylvania counties. The deposits described below were briefly visited by the writer 

at different times between 1912 and 1915, and the descriptions given 

show the conditions found at the time of the examination.

The mica deposits of Virginia lie in the counties within the Piedmont Plateau, southeast of the Blue Ridge. Parts of the region are 

strongly dissected by river valleys and contain monadnocks and 

residual hills or small mountains. The relief in the eastern counties, 

from Hanover to Charlotte, which are in typical Piedmont country, 

is comparatively slight, but the relief between valley and residual 

hill in some of the more western counties in which mica has been 

found, such as Bedford and Franklin is so great that the region 

appears almost mountainous.

The rocks in the different mica regions consist of pre-Cambrian 

gneisses and schists of many varieties. The Amelia-Goochland-Han88 Mineral production of Virginia in 1908: Virginia Geol. Survey Bull. 1-A, p. 104, 1909.
308 MJCA DEPOSITS OF THE UNITED STATES.

over county belt is in an area mapped as "granite, granite gneiss, 

with schists, often intruded with pegmatites, etc.," by T. L. Watson.90 

Deep weathering of the rocks in this belt makes it difficult to distinguish the underlying type of rock, but mica and garnet gneiss 

and schist were observed rather plentifully around the mica deposits. Watson maps the rocks in part of Prince Edward, Charlotte, Pittsylvania, Henry, and Franklin counties as " crystalline 

schists and gneiss." These rocks are the northeasterly extension of 

the Carolina gneiss and Roan gneiss of Keith, in North Carolina. 

The mica-bearing pegmatites occur principally in the gneisses and 

schists in the Amelia-Hanover county belt, but a few may be associated with the granite gneiss. In the western belt the deposits 

occur in both mica and garnet gneisses and in hornblende gneisses. 

The occurrence of the pegmatite in the Virginia mica mines presents few unusual features outside of the mineral associations in 

some deposits. Feldspar for pottery and agricultural use and mica 

are quarried together at some mines, the one as a by-product in 

mining the other. At a few places gem and specimen minerals have 

been found in more or less abundance with the mica, the deposit at 

Amelia yielding amazon stone, blue chatoyant oligoclase, albite, 

spessartite, and rare-earth minerals.

AMELIA COUNTY. 

RTITHERFOORD MINE.

The A. H. Kutherfoord mine is 1£ miles north of Amelia Courthouse. It has been almost as famous for the gem and specimen 

minerals it has yielded as for its mica. The output of mica was 

rather large during the early days of working, but about 1908, 

during the last operations for gem minerals by the American Gem 

& Pearl Co., the output was small. Descriptions of the mine and 

its minerals have been given by W. H. Fontaine,01 T. L. Watson,92 

E. S. Bastin,93 and D. B. Sterrett.94 Fontaine mentions evidences 

of early work by Indians or others here and at other mica mines 

of this region. The mica vein is reported to have been removed to 

a depth of 10 feet on the outcrop and the rubbish to have been 

thrown back or washed into the workings.

The deposit was mined at two points about 90 yards apart on a 

line running southwestward. The opening to the northeast, which

90 A geological map of Virginia, Virginia Geol. Survey, 1911.

81 Notes on the occurrence of certain minerals in Amelia County, Va.: Am. Jour. Sci., 

3d ser., vol. 25, pp. 330-339, 1883.

82 Mineral resources of Virginia, Virginia Jamestown Exposition Comm., pp. 282, 

385-392, 1907.

83 Quartz and feldspar: U. S. Geol. Survey Mineral Resources, 1910, pt. 2, pp. 971-973, 

1911.

91 Gems and precious stones: U. S. Geol. Survey Mineral Resources, 1912, pt. 2, pp. 

1045-1048. 1913.
VIRGINIA. 309

Fontaine called No. 1, is on a low hill; the other opening, called 

No. 2, is in a bottom close to a branch. At the time of Fontaine's 

examination in 1883, or earlier, there was a shaft, less than 80 feet 

deep, at each place. In August, 1912, opening No. 1 consisted of 

a pit about 75 feet long in an easterly direction and 40 feet wide 

and a shaft east of the pit. The pit was formed by the caving in of 

old shafts and tunnels. The shaft was made by the American Gem 

& Pearl Co., of New York, and is reported to be 90 feet deep. A 

40-foot drift is run from it at the 55-foot level. At opening No. 2 

there is a pond about 50 feet wide and 150 feet long from east to 

west, showing the surface area of the old work. It is reported that 

the deepest work here was a shaft sunk 150 feet.

The exposures of " vein " and country rock around the " vein " are 

very poor. The country rock is biotite schist and gneiss containing 

considerable feldspar. An exposure of a slightly garnetiferous phase 

of this gneiss on the hillside between the two openings showed a 

strike of N. 55° W. and a dip of 20° NE. The extension of the 

working^ indicates nearly parallel " veins " striking about east. Fontaine believes openings Nos. 1 and 2 were on the same deposit but 

calls attention to the difference in the mineral associations. The 

impression gained by the present writer -is that the two deposits 

are not connected, at least not near the surface.

.The " veins" are pegmatite of somewhat unusual composition and 

texture for the southern Appalachian region. The normal minerals 

of pegmatite are present, but they occur in great variety and are 

associated with minerals that are of interest as gems or specimens. 

Quartz occurs both in irregular masses and in crystals, the largest 

weighing 8 or 10 pounds. The ordinary quartz is glassy and opaque 

gray and the crystals are semitransparent to clear white, colorless, 

or smoky brown. The mica is muscovite of fine quality, which in 

sheets a millimeter or more thick has a clear light-brownish color. 

Large quantities of fine stove mica were obtained, and sheets measuring 22 by 24 inches are reported to have been cut from some of the 

crystals.

The specimen and gem minerals obtained here have already been 

described,96 but they will be briefly mentioned because of their unusual interest. The variety of feldspars is unusually great for a 

single deposit of pegmatite. Potash feldspar occurs chiefly as grayish-white, bluish-green, and green microcline. Some specimens of 

this mineral are slightly translucent and the colors are bright, qualities which adapt it to use as a gem. The other feldspars are albite

00 Gems and precious stonps : U. S. Geol. Survey Mineral Resources, 1912, pt. 2, pp. 

1045-1048, 1913.

111375 23 21
310 MICA DEPOSITS OF THE UNITED STATES.

and oligoclase. The albite occurs in clusters of white to colorless 

tabular crystals, the largest half an inch thick and 3 inches long. 

Masses of these clusters were 18 inches thick. The oligoclase is the 

sodic variety of feldspar. It occurs in rough crystals, some of which 

have perfect cleavage and measure several inches across. On certain 

faces some of the crystals exhibit a beautiful pearly blue chatoyancy. 

Crystals of this variety make fine specimens, and some of them are 

suitable for gems. Transparent reddish-brown spessartite garnets 

that cut into beautiful gem hyacinth were also found. Some of the 

spessartite crystals are reported to have measured 3 inches in 

diameter.

Among other minerals found were crystals of smoky and colorless 

quartz, large crystals of beryl, the chlorophane variety of fluorite, 

remarkable for the strength of its phosphorescence, fine crystals of 

monazite and microlite, columbite, allanite, orthite, helvite, apatite, 

galena, stibnite, zircon, and pyrochlore.

The presence of these various gem and specimen minerals should 

be taken into consideration in making plans for mining, for they 

could be made to pay part of the cost of the work and might prove 

to be the most profitable part of the output.

JEFFERSON OR CHAMPION MINES.

The Jefferson mines are about 2| miles N. 20° E. of Amelia Courthouse, along the west side of the public road. They were the first 

mica mines opened in the Amelia region and have a good reputation 

among the early miners as large producers, especially the old Champion mines Nos. 1 and 2. The Jefferson mines have been worked by 

different persons under lease, and the last work was done by J. Boyd 

Bland, of Richmond, in 1913 and 1914. Most of the work was done 

at three places, all within 75 yards of the road. Champion mine No. 

1 is in the middle, No. 2 is 350 yards to the southeast, and the third 

mine is about one-third of a mile to the northwest. The mines were 

visited briefly in 1912 and again in August, 1914. In 1912 all the 

mines were idle and in 1914 Champion mine No. 1 had just been 

closed down and prospecting was in progress at the working No. 2. 

No work has been done at the northern working for several years.

At the time of the first visit to Champion mine No. 1 there was a 

pit about 40 feet long, 20 feet wide, and 10 feet deep where old workings had caved in, and large dumps were spread over the nearly flat 

ground around them. The dumps had been pretty thoroughly worked 

over for small sheet and scrap mica that had been thrown away during earlier mining. The later work done by Mr. Bland consisted 

of a shaft more than 130 feet deep, and irregular stopes and tunnels 

where rich streaks of mica were found. The shaft was 80 feet deep
VIRGINIA. 311

 vertically and 50 feet deeper to water, on an incline of about 50° 

west by south. Work had been abandoned a few days prior to the 

examination, and the shaft was filling with water. The approximate 

positions of the stopes with respect to the shaft and incline are shown 

in plan and cross section in figure 89. The stopes are so irregular 

that they would be termed " ground-hog workings " in some mining 

regions, but they served to remove all pay rock with the least labor. 

The mine equipment consisted of a 75-horsepower boiler, an engine 

hoist, a head frame, a track, and a mine car.

The country rock is biotite gneiss, apparently granitic, which 

strikes northwest and dips southwest at a high angle. The pegmatite appears to be a short, thick lenticular chimney or shoot that extends to a depth of more 

than 130 feet. It has been opened for not more 

than 50 feet north and south and its thickness 

is 25 to 30 feet. It consists of various mixtures 

of feldspar, quartz, and mica. It contains both 

potash feldspar (orthoclase or microcline) and 

soda feldspar (albite). The orthoclase incloses

PLAN

some small scales of mica along the cleavage 

planes. Some of the albite occurs in tabular 

crystals as much as one-eighth of an inch thick 

and 2 to 3 inches across, intergrown at different 

angles. The interstices are filled with finergrained feldspathic material containing small 

crystals of black tourmaline. Quartz occurs in 

large opaque masses and crystals and smaller 

smoky-gray, and colorless translucent to clear 

masses and crystals. The mica is not regularly 

distributed through the pegmatite, but occurs 

in pockets and streaks, some of which were 

very rich. Mr. Bland removed about 200,000 

pounds, from which 15,000 pounds of sheet 

mica was trimmed, the rest going for punch 

and scrap. Mr. Bland states that some sheets 12 inches wide could 

be cut from the larger crystals. The mica has a clear brown color 

and splits with a smooth, flat cleavage. The sheet mica is suitable 

for stove windows.

At mine No. 2 the old workings consisted of a shaft about 60 feet 

deep, 200 to 300 feet of drifts and stopes, and several prospect pits. 

The old workings have caved badly or have been filled with muck 

and mud and could not be examined. New work by Mr. Bland 

consisted of two shafts about 60 feet deep and 60 feet apart on a 

line running from northeast to southwest, and tunnels driven from;

CROSS SECTION

looking north

FIGURE 89. Plan and 

section of Champion 

mine No. 1 of Jefferson mines, 2J miles 

N. 20° E. of Amelia, 

Amelia County, Va.
312 MICA DEPOSITS OF THE UNITED STATES.

them, as shown in figure 90. One tunnel was driven from the 

northeast shaft to the old shaft arid abandoned because of caving 

ground. Another tunnel was cut betAveen the tAVO new shafts around 

the east side of the old shaft. This cut into old workings that 

had been partly filled Avith Avashes of muck and mud. An old 

tunnel to the east, noAv filled, is reported to have been driven 200 

feet. The surface arrangement is shown in Plate XXIX, A (p. 301). 

The southwest shaft is in the foreground and the northeast shaft is 

beyond the engine shelter.

The country rock is someAvhat granitic biotite gneiss having a 

northwest strike and southeast dip. The pegmatite cuts the bedding of the gneiss, but the exposures Avere not plentiful enough to 

permit a determination of its strike and dip. Apparently it is 

elongated eastward, but it is at least 60 feet thick and probably 

as much as 75 feet thick from north to south. It contains horses 

PIT PI7 PIT of gneiss. The formations 

^ ^'--^~ \ are thoroughly decomposed

to the depth of the loAvest 

AV or kings, 60 feet. The 

pegmatite varies in grain, 

i; / / ' part of it being rather fine.

.j-i --.__''_^_ ZV-3-rOGT DRIFT DRIVEN i , i't "3. ~-\--^^ii^^-~-~---::::>»ToaA«*E"''£M almost like coarse granite, 

^-:;:;:::;:;:'..'f' and part very coarse, containing masses of Avhite n «.-) ,nn -TFT 

quartz several feet thick..

Mudfiii _ _ _ ^ ,.,, The mica occurs in streaks 1J~"

FIGURE 90. Plan of Champion mine N7 o. 'J oi , 

Jefferson mica mines, 21 miles N. 20° B. of the masses 01 quartz. JLWO

Amelia, Amelia county, va. streaks of mica were encountered. One of these, found in the earlier workings, was reported to be rich; the other, near the north shaft, was rich in 

places, but most of the mica was in small crystals. Much of the 

pegmatite is nearly barren of mica. The best mica obtained during the last work yielded sheets 4 by 6 inches and of the same good 

quality as that from mine No. 1.

Future work would have to be directed toward deeper mining, 

probably 75 feet and lower, to avoid the danger of caving and to 

cut the richer mica streak at a lower level.

At the north working an open cut 30 feet wide and 20 feet deep 

extends eastward 60 feet. The formations are soft and the walls 

have caved in, partly filling portions of the pit. The country rock 

is decomposed gneiss, probably garnetiferous granite gneiss. The 

pegmatite evidently occurs in a large lenticular mass, probably 50 

to 60 feet long and 25 feet thick, for no exposures have been left 

in the north, south, or west walls, and a streak only about 18 inches
VIRGINIA. 313

thick is exposed in the east end of the cut. Colorless to translucent 

and clear smoky quartz had been thrown on the dumps, and some 

small crystals and weathered sheets of mica had been left mixed with 

the waste.

MINES OF VIRGINIA MlCA PRODUCING & MANUFACTURING CO.

Several deposits have been opened by the Virginia Mica Producing & Manufacturing Co. (formerly the Virginia Mica & Mining 

Co.) on the old Pinchbeck property, 3 miles N. 17° E. of Amelia 

Courthouse.. These deposits were idle at the time of the first visit, in 

August, 1914, but one of them was being worked when visited in 

June, 1915. There were two principal mines; the others were only 

prospects. The first large deposit worked is on the east side of a 

plantation road and will be called mine 

No. 1. The second is on the west side of 

the road about 350 feet southwest of it 

and will be called mine No. 2. The position of these workings is shown in figure 91.

Work on mine No. 1 had been stopped 

prior to August, 1914, and at the time of 

visit the last of the sheet mica ftom it was 

being split and trimmed. The workings 

consist of an open cut 30 feet wide and 

25 to 35 feet deep, which extends eastward 

for 80 feet and inclines to the east and 

west, and of a shaft 35 feet deep, run from 

the bottom of the cut. The equipment for 

this work consisted of a boiler, a hoisting 

engine, a derrick, incline tracks, a car, and 

a steam pump.

The country rock is decomposed mica 

gneiss, which strikes variably between 

east and northeast and dips high to the north and northwest. 

The pegmatite cuts the gneiss with an easterly strike and an almost 

vertical dip. It has a maximum thickness of about 20 feet and has 

been followed in the workings for about 150 feet. It is 5 feet thick 

at the east end of the open cut and 10 feet thick at the west end. 

Large masses of quartz were encountered and had to be removed in 

mining. Some of it was shipped. Mica was obtained in fairly large 

quantity, but it contained a large proportion of rough crystals good 

only for scrap. Some clear sheets measuring 8 by 10 inches, suitable 

for stove windows, were cut from the best crystals, but most of the 

sheet mica cut was much smaller. The mica has a clear light applegreen color where it is free from stains produced by weathering, but 

much of it is stained yellowish by limonite washed into the cleavages.

Pegmatite 

>- Strike and dip of gneiss

ioritT) 91. Sketch showing 

position of workings at mines 

of Virginia Mica Producing 

& Manufacturing Co., 3 miles 

N. 17° E. of Amelia, Amelia 

County, Vi\.
314 MICA DEPOSITS OF THE UNITED STATES.

Mine No. 2 was in operation in June, 1915. There was a small 

open cut, a shaft 45 feet deep on the northeast side of the cut, and 

a 25-foot drift run N. 60° E. from the 40-foot level. The country 

rock is much folded biotite gneiss having a general northeast strike 

and northwest dip. The pegmatite also strikes northeast. The tunnel cuts slantwise across the pegmatite, which forks at the northeast 

end. The pegmatite is 3 to 10 feet thick and has been decomposed 

to a depth of nearly 40 feet, below which weathering has affected 

it but little and the potash feldspar is fresh. The pegmatite exposed 

in the workings is rich in crystals of mica, some of which are more 

than 18 inches across. Much of the mica is the A variety, or ruled, 

and some is rather badly stained with limonite from surface weathering. The staining is not so bad as 

that in the mica from mine No. 1, 

but the color and quality are otherwise similar.

The company has a shop and 

trimming house near mine No. 1 

and has experimented with a locally 

made wet grinding machine. At 

the time of visit this had not been 

perfected.

PINCHBECK MINES.

300 FEET

FIGURE 92. Sketch showing position of workings at Pinchbeck 

mica-feldspar mines, 3 miles 

northeast of Amelia, Amelia 

County, Va. See text for explanation of numbers.

Several mines have been worked 

on the Pinchbeck property, about

3 miles northeast of Amelia Courthouse. Most of the workings lie 

within an area of about 600 by 300 

feet, as shown in figure 92. 

At least three veins were opened, one in the large open cut at 1, another in the cut at 2, and a third in the large open cut at 3. It is 

possible that the vein at 2 continues northwest to the pit at 2a, 

and the vein at 3 probably strikes into the workings at ,3a. E. S. 

Bastin M describes the deposit at 1, and some of the following notes 

are taken from his description. The open cut at 1 is nearly 100 feet 

long east and west, 60 feet wide, and 15 to 18 feet deep to water. 

The depth of water in the bottom was not determined but is probably at least 10 feet. A hoisting frame and platform had been 

built over the pit on the north side. The country rock is partly 

weathered dark mica schist and gneiss, containing muscovite and 

biotite. It has been much folded and crumpled but has prevailing

M Quarta and feldspar: U. S. Geol. Survey Mineral Resources, 1910, pt. 2, p. 972, 1911.
V1KG1NIA. 315

northeast strike and northwest dip. The body of pegmatite is about 

35 feet thick at the west end of the cut and one prong of it at the east 

end is 20 feet thick. Smaller streaks fork out into the gneiss near 

the southeast corner of the cut. The minerals are segregated into 

rather large masses. Quartz and feldspar occur in nearly pure 

masses 3 to 4 feet thick. The feldspar is the light cream colored 

potash variety. Some of the quartz is clear and glassy and has 

rough crystal form. A micaceous streak 8 to 12 feet thick lies along 

the north side of the pegmatite. Most of the mica in this streak is 

small and of poor quality, but some good sheet material has been 

obtained.

At 2 a small body of pegmatite 2 to 6 feet thick was opened 

in a cut 30 feet long and 20 feet deep. The schist and gneiss here 

strike N. 50° W. and dip vertically, and the pegmatite cuts them with 

a similar strike and southwest dip. At 2a part of a pegmatite is 

exposed in a shaft. The mica schist on the northeast wall of the 

pegmatite here strikes northwest and dips vertically.

At 3 there is a large open cut, which is filled with water to a 

point within 10 feet of the surface. No exposures of pegmatite were 

seen. The shafts and open cuts at 3a expose a promising-looking 

deposit of pegmatite, in which quartz and feldspar are segregated 

into masses 2 to 3 feet thick. Good mica also occurs in this vein 

and some was removed in mining.

Much of the sheet mica from the different workings has a clear 

rum color and smooth cleavage and is suitable for stove windows. 

Some of it contains imperfections, such as tangle-sheet structure, 

rulings, and clay stains. As the mining extends deeper the clay 

staining will probably disappear. Feldspar has been shipped from 

the larger workings of the Pinchbeck mines for use in making 

pottery.

PATTEHSON MINE.

The Patterson mine is a little more than 2 miles N. 20° E. of 

Amelia Courthouse. It is an old mine in the bottom of a small 

valley and consists of an open cut 50 feet wide, which extends 80 feet 

eastward and is filled with water. It is evidently deep, and one 

shaft is reported to have been sunk to a depth of 90 feet. Large 

dumps have been piled northeast and southwest of the cut. A small 

open cut has been driven from the south side of the main cut into 

the hillside and exposes the only rock now visible in the workings. 

In this exposure the country rock is biotite gneiss, which strikes 

N. 15° E. and dips east at a high angle. Only a small bed of pegmatite wa$ opened in this cut. Potash feldspar, albite, mica, a little 

garnet, and allanite were observed on the dumps. Only small crystals of mica were left in the dumps, but they are clear brownish-
316 MICA DEPOSITS OF THE UNITE!) STATKS.

colored crystals that have a smooth cleavage and are of a good grade. 

The mine is reported to have been a good producer.

PROSPECTS OF INTERNATIONAL MICA CO.

The International Mica Co., represented by L. J. Bussey arid 

J. A. Crabtree. of Philadelphia, tested two prospects during 1915. 

One of these is about 125 yards northeast of the Patterson mine, just 

described (see fig. 93, A, or a little more than 2 miles N. 20° E. of 

Amelia Courthouse. The other prospect was opened after the 

writer's visit in June, 1915, near the workings of the Virginia Mica 

Producing & Manufacturing Co. The prospect near the Patterson mine was opened several years ago at the side of a small branch 

40 _ " and is reported to have found good 

mica. The last work consists of a 

shaft 40 feet deep about 20 feet northwest of the old work.

The country rock is garnetiferous 

biotite gneiss in which the garnets 

iire of a rose-pink color and have an 

average diameter of 2 millimeters. 

The gneiss has a northwest strike and 

:i variable dip, approximating 40° 

NE. The pegmatite has a northwest 

strike and a dip averaging about 65° 

NE. J t is conformable with the gneiss 

for a few feet and then cuts across its 

bedding by offsets through the next 

few feet. (See fig. 93, B.) The pegmatite presents no unusual features 

in its composition. Only small mica 

Avas seen, but some of good size 

is reported to have been found. 

The mica has a clear brown color and splits with a smooth flat 

cleavage. The International Mica Co. closed its prospects toward 

the end of 1915.

MARSHALL MINES.

Several deposits have been opened on the H. 0. Marshall property, If to 2 miles N. 25°-30° W. of Amelia Courthouse. One of 

these is just northwest of the public road and railroad. It was 

worked by two large pits or medium-sized open cuts, extending N. 

60° W. The pits are about 18 feet deep to water. The country rock 

is weathered biotite gneiss. A quantity of massive quartz and small 

mica was thrown on the dumps and masses of quartz* and mica 

"capping" crop out near the pits. Little could be learned of the 

output of mica from these openings.

JB

FIGURE 93. Mines of the International Mica Co., 2 miles N. 20" 

E. of Amelia, Amelia County, Va. 

A, Sketch, showing location of deposit and Patterson mine; B, ideal 

cross section of pegmatite in shaft 

of International Mica Co.
VIRGINIA. 317

Another deposit was opened 250 yards north of the one on the 

railroad and a third is about 250 yards west of north of the second. 

Small plates of mica of good quality were left on the dumps. Other 

deposits lie about a third of a mile west of north of the one on 

the railroad. Little could be seen of the formations in them and 

only small crystals of mica had been left on the dumps. These 

prospects are reported to have yielded small quantities of valuable 

mica.

BERRY MINE.

The old Berry mine, now owned by Mr. Bicheson, is i|- miles 

N. 35° E. of Amelia Courthouse, on the southeast side of the Southern Railway track. At the time it was visited, in August, 1912, 

there was a pit 35 feet across and 15 feet deep to water, with a 

cribbed shaft 12 feet square in the bottom. This pit has since been 

filled up and leveled off for farm cultivation. The country rock 

in the vicinity is decomposed biotite gneiss, which has slight dips 

in various directions and shows gentle folding. The pegmatite appears to have an east to an east by south strike. The exposures 

were poor and the character of the pegmatite had to be learned 

from material in the dump. The dump contained a little unweathered orthoclase, numerous fragments of bluish-green microcline or 

amazon stone, most of them partly weathered, and small crystals 

of mica. One small crystal of columbite was found. A block of 

brown and yellow stained chalcedonic quartz, 15 inches thick, had 

been left on the dump. It contained crystal-lined cavities but was 

suitable for cutting into a semiprecious stone. The mica is clear 

and is of light-brown color. About 100 yards north of this deposit 

three other pits were opened for mica. These had been filled up and 

little could be seen of the formations.

KEYSTONE MICA CO. MINE.

The Keystone Mica Co. mine is 4| miles N. 80° W. of Amelia 

Courthouse and 4£ miles N. 25° W. of Jetersville. It was worked 

first in 1907 and again in 1914, after a period of idleness. The work 

consists of a shaft 40 feet deep with a small open cut. A shaft house 

and engine house have been erected over the workings. The shaft 

is filled with water to a point within 18 feet of the surface.

The country rock is schistose diorite, which strikes N. 15° W. and 

dips vertically. Two bodies of pegmatite have been worked, one 6 

to 8 feet thick and about conformable with the inclosing gneiss, and 

the other 3 feet thick, probably a branch of the main " vein," but not 

worked at the point of branching. Both pegmatites are reported to 

carry mica in good quantity, but the larger one yielded the largest 

crystals. The mica is clear and has a rather dark greenish-brown
318 MIGA DEPOSITS Otf THE UNITED STATES.

color. It splits smoothly and yields sheets suitable for the glazing 

trade. Mr. F. W. Corson, of Jetersville, the manager, states that the 

crystals are sound and clean as mined and yield about 40 per cent of 

sheet mica suitable for punching and trimming.

SCHLEGEL OR NORFLEET MINE.

The old Schlegel mine, now belonging to Mrs. K. P. Norfleet, is 

1 mile N. 70° W. of Jetersville. The mine was opened between 1880 

and 1885 and the last work was done about 1900. The workings consist of an open cut 18 feet deep and 60 feet long, run northwestward, 

and two shafts. It is reported that one of these shafts is about 100 

feet deep and has drifts and stopes run from it, but both were filled 

with water at the time of the examination, in August, 1912. The 

dumps are large and show considerable work. A mill for grinding 

feldspar was erected at the mine at the time of the last operations.

The country rock is chiefly highly schistose diorite, in which some 

schistose granite is interbedded. At the mine these formations strike 

N. 15° W. and have a vertical or high east dip. The pegmatite is 

large in the main part of the mine but pinches to about 10 feet thick 

in the northwest end of the open cut. It cuts the bedding of the 

inclosing rocks. Fragments of fresh pinkish-gray potash feldspar 

were seen on the dumps. The mica is clear but is darker in color 

than most of that found in Amelia County.

Other outcrops of pegmatite occur in the Norfleet property, one 

of which has been traced more than a quarter of a mile northward. 

The outcrops are 10 to 30 feet wide and contain large crystals of 

feldspar, segregations of quartz, and bunches of " mica capping " or 

crystals of A and wedge mica mixed with quartz or feldspar.

BEDFORD COUNTY. 

AMERICAN ASBESTOS CO.'S MIKE.

Mica was mined several years ago by the American Asbestos Co. 

on property now owned by Frank Mosher and associates, 9 miles 

east by south of Bedford City, Bedford County. The deposit was 

worked by an open cut 40 feet long, and 20 feet in greatest depth, 

and a shaft, now filled with water, reported to be 30 feet deep, in the 

end of the cut. The open cut was driven northwestward into a 

hillside about 30 feet above a creek. A hoist was arranged over the 

shaft, and a tram extends from it to the shop and storehouse, about 

40 feet to the northwest. The position of the workings and shop 

is shown in figure 94.

The country rock is hornblende schist or schistose diorite, badly 

weathered to a reddish-brown earth. The pegmatite is approximately conformable with the inclosing schist, striking N. 30° E.
VIRGINIA. 319

and having a nearly vertical dip. Where exposed in the open cut 

it is nearly 20 feet thick. The east half is highly feldspathic and the 

west half contains more quartz and is richer in mica. The quartz 

occurs in irregular masses and in small sheets or lenses parallel with 

the walls of the pegmatite. 'A horse or sheet of hornblende schist 

1 foot thick is also included in the pegmatite. Opaque reddish garnets are abundant, and some flattened garnet crystals are inclosed between the sheets of mica. Much of the mica has the A structure 

but would yield good sheets from the part between the A lines. 

Crystals of mica 8 or 10 inches across were seen in the shop, where 

several tons of rough mica is stored.

The mine could have been worked to better advantage from a 

lower level on the hillside about 75 feet to the southwest, as indicated

FIGURE 94. rian of the mica mine of the American Asbestos Co., 9 miles east-southeast 

of Bedford City, Bedford County, Va.

in figure 94. A crosscut prospect trench would have located the 

pegmatite at this point, if continuous as indicated in the figure, 

and mining could have been carried on by open work or drift with 

stopes to the northeast.

FRANKLIN COUNTY. 

CHESTNUT MOUNTAIN MINES.

Mica has been mined and prospected at several places in the Chestnut Mountain region, about 12 miles southeast of Eocky Mount, 

Franklin County. The principal work was done by the Chestnut 

Mountain Mica Co., on the east side of the mountain, and consisted 

of an open cut 50 feet long and 5 to 12 feet deep along a steep 

hillside on the outcrop and a shaft connecting with drifts and a 

crosscut tunnel about 20 feet lower at the foot of the hill.
320 MICA DEPOSITS OF THE UNITED STATES.

The country rock is mica and kyanite schist and gneiss. The strike 

of the inclosing schist as measured varied from N. 40° E. to N. 70° E. 

and the dip from 40° to 60° SE. The pegmatite cuts the country 

rock with a strike ranging from N. 80° W. to nearly west and a variable clip of about 60° N. The pegmatite ranges in thickness from 2 

feet in the east end of the cut to more than 8 feet in the west end. 

The feldspar content has been strongly kaolinized, and the inclosing 

schist has been badly decomposed. Mica seemed to be rather plentiful but consisted chiefly of small and ruled crystals, so that the yield 

of sheet mica would not be large. Under favorable conditions of 

transportation it might pay to work the mine for scrap mica alone. 

A rotary screen had been set up to dry-clean the scrap mica from 

dirt and would not need much improvement to meet ordinary requirements. Several tons of scrap mica could be cleaned up from waste 

now lying around the mine.

A small open cut had been made about 200 feet west of the mine 

and about 50 feet, higher up the hill. It may be on the same body 

of pegmatite as the lower working, but the pegmatite at this place 

contains more quartz and a quantity of " mica capping," or quartz 

mixed with small mica crystals. The property was examined in 1913. 

Since that time more work lias been done and some large mica is reported to have been found in openings to the southwest on the hill.

About a quarter of a mile north of the mine a 15-foot shaft or 

pit had been sunk on a pegmatite near the main road to Rocky 

Mount. The pegmatite exposed in this opening was 10 feet thick. 

It was badly decomposed and the inclosed mica had been strongly 

broken and ruled into small sheets. A mica crystal 18 inches across 

was seen, but it was so badly crushed that only small sheets could be 

cut from it. Plates nearly a foot in diameter are reported to have 

been found. The mica is rather plentiful, but most of it is in part 

"specked." Large black tourmaline crystals were found in the 

pegmatite.

About H miles northwest of the main mine there is an old prospect for mica consisting of a shaft about 20 feet deep. The country 

rock here is mica schist, which strikes N. 35° E. and dips 70° SE. 

The pegmatite is approximately conformable with the inclosing 

rock and is about 2| feet thick near the surface. Hard blocks of 

mica capping 2 feet thick had been removed from the shaft. Only 

small crystals of mica about 2 inches across were left on the dump. 

The pegmatite contains black tourmaline and opaque red garnets.

GOOCHLAND COUNTY. 

IRWIN MINE.

The old Irwin mica mine, now owned by Mr. Fink, is 2| miles N. 45° 

W. of Maidens or 2 miles N. 60° W. of Goochland. It had been idle
VIRGINIA. 321

for about 15 years prior to the time of the examination, in September, 

1912. The workings consist of a pit or open cut 25 feet across and 

20 feet deep and a shaft, reported to be 50 feet deep, in the bottom.

The country rock is biotite gneiss, into which are injected streaks 

and lenses of pegmatite. The mica-bearing pegmatite is only 2 feet 

thick where it is exposed in the side of the pit but was apparently 

much thicker where worked. This tendency to lenticular development is shown by the small bodies of pegmatite inclosed in the gneiss 

near the mine. The " vein " strikes north of east, dips north, and incloses streaks of gneiss. Only small crystals of mica were seen on the 

dumps, but these had a clear light rum color. The mine is reported 

to have yielded tr good quantity of marketable sheet mica.

REED MINE.

The mine of Mrs. E. P. Reed is 1-J miles N. 20° W. of Maidens. 

No work had been done for 12 or 15 years prior to the time of examination, in September, 1916. The workings consist of an open cut 75 

feet long, 25 feet wide, and 20 feet deep, run southeastward, and 

some shaft work now caved in. Little could be seen of the formations. Small plates left on the dump show that mica of good quality, 

having a clear light rum color and flat cleavage, was obtained.

HANOVER COUNTY. 

C. W. SAXTNDERS MINES.

Several prospects and mines have been opened on land now owned 

by C. W. Saunders, 2 or 3 miles south of Hewlett. According to 

T. L. Watson,07 this property was worked first from 1867 to 1870 

by Barr, Johnson & Co., of Erie, Pa., and produced more than 60,000 

pounds of trimmed stove mica. A little more work was done in 1883 

and more in 1907. Four workings were visited in August, 1914, Mr. 

S. A. Butler, of Hewlett, acting as guide. These were called mines 

Nos. 1, 2, 3, and 4. Mines Nos. 1 and 2 are close to each other, No. 1 

being near the south bank of Little River.

Mine No. 1 was worked by an open cut 60 feet long, run northeastward, which was 35 feet deep at its southeast or deepest end. Mr. 

Butler states that this cut now contains 15 to 20 feet of rubbish. The 

large dumps built out on the river bank show that much vein matter 

was removed. The country rock consists of interbedded garnet gneiss 

and granite gneiss.

Mine No. 2 is about 100 feet southeast of No. 1, on the east side 

of a small valley that drains into Little River. It was opened by a 

long trenchlike cut that extends nearly 100 feet southwestward into

117 Mineral production of Virginia in 1908: Virginia Geol. Survey Bull. 1-A, p. 104, 1909.
322 MICA DEPOSITS OF THE UNITED STATES.

the end of a ridge. The northeast half is about 30 feet deep but 

at the time of examination was half filled with water, and the southwest half is about 10 feet deep. A track and car were used to carry 

the waste rock to the main dump in the flat ground across the branch.

The country rock is garnet gneiss, which strikes N. 30° E. and 

has a variable northwest to rolling, nearly flat dip. The pegmatite 

cuts across the gneiss with a strike of N. 70° E. and a vertical dip 

and is about 10 feet thick where the deep work was done and 2 feet 

thick in the southwest end of the cut. Both the garnet gneiss wall 

rock and the pegmatite are fresh and hard. The pegmatite contains translucent to clear quartz, potash feldspar, some of which 

has a moonstone-like chatoyancy, and a few garnets. Rough crystals 

of feldspar 8 to 10 inches thick and a few blocks of graphic intergrowths of feldspar and mica were seen on the dump. The mica 

is of good quality, has a smooth, flat cleavage, is of rather dark 

or smoky rum color, and splits into clear light-colored sheets suitable for stove windows.

Mine No. 3 is about three-quarters of a mile south of Nos. 1 and 2, 

in the northeast side of a spring branch. It was worked by an 

open cut 100 feet long driven east into the hillside. The cut is 18 

feet deep to water at the inner end, but the depth below water could 

not be learned. The workings are overgrown by vegetation and 

show great age. The dumps are large, and the mine is reputed to 

have been a good producer.

Mine No. 4 is about half a mile west of south of Nos. 1 and 2. 

It was opened by a cut TO feet long, which extended eastward across 

the summit of a small ridge, but the work was not carried deep, 

and the results are said to have been indifferent. The rock formations have weathered down to a reddish-brown clay soil, such as 

would be produced by the decomposition of garnet gneiss. Large 

blocks of white quartz had been thrown on the dumps.

Mr. Saunders has some pale-green microcline (amazon stone) 

which is said to have come from these mines, but was probably 

brought from the Rutherfoord mine, near Amelia Courthouse, when 

Mr. Henry Mackay moved machinery and mine supplies from Amelia 

County in 1907. No specimens of amazon stone were observed on the 

dumps or around the mines.

HENRY COUNTY.

0

GENERAL FEATURES.

Mica has been mined and prospected for at several places near 

Ridgeway, in Henry County. Attention was drawn to the deposits 

some years ago by Capt. McCray, of Ridgeway, who opened many of 

them and interested some persons from Pittsburgh, Pa., by whom
VIRGINIA. 323

most of the mining has been done. The writer visited the region 

around Ridge way early in the autumn of 1913, when the descriptions 

given below were prepared.

Ridgeway is in a rather strongly dissected part of the Piedmont 

Plateau. Some of the hills have moderate slopes, but in places the 

valleys have steep walls. The elevation at a United States Geological Survey bench mark near the Norfolk & Western Railway station 

is 834 feet above sea level. Some of the ridges in the vicinity, such 

as that on which the town of Ridgeway is situated, rise at least 100 

feet higher.

The country rock along the mica belt in the region is chiefly diorite, 

more or less schistose and in places cut by fine aplitic granite and 

pegmatite. Streaks of mica schist and garnet "schist and a belt of 

soapstone are inclosed in the diorite country rock near the belt of 

mica. The strike of the formations is in general northeast, ranging 

from N. 20° E. to N. 60° E. The dip of the bedding is generally 

high to the west or nearly vertical, but a few exceptions were noted.

RIDGEWAY MICA CO.'S MINE.

The Ridgeway Mica Co., of Ridgeway, is an outgrowth of the 

former Pittsburgh Mica Co. The new company was formed by 

P. Lippert, of Pittsburgh, Pa., and associates after a period of idleness that followed rather extensive operations by the Pittsburgh 

Mica Co. The Ridgeway Mica Co. owns a large area of land around 

Ridgeway on which both mica and feldspar have been mined or 

prospected for. In 1913 the principal mine, about a quarter of a mile 

northwest of the railway station, was operated for mica, and 

prospecting was carried on at some of the other deposits.

The mine has been worked by open cuts, shafts, and stopes for 

about 160 feet in a line running N". 25° E. to a depth of about 120 

feet, as shown in the generalized sections in figure 95. The. workings 

are irregular in shape, corresponding to irregularities in the vein. 

Mining has been carried on from different openings, beginning with 

the cut at the north end and working southward and deeper to the 

present shaft and down stope from its bottom. Large stopes have 

been made, which elbow out in places where there were bulges in 

the vein.

The country rock is schistose diorite, which strikes about N. 25° E. 

and dips west at a high angle. The dip and strike vary locally, 

especially around the irregularities of the pegmatite. In places the 

wall rock has been metamorphosed to quartz-biotite schist by contact 

with the pegmatite. The pegmatite as a whole is approximately 

conformable with the inclosing schistose diorite. It does not all lie 

between two plane parallel walls, but elbows out to the west by a
324 MICA DEPOSITS OF THE UNITED STATES.

series of bulges, so that the average dip is about 75° W. Notes on 

the pegmatite at the different places numbered in figure 95 are given 

below:

1. Pegmatite 6 feet thick; contains fine mica, some in crystals weighing 

several hundred pounds.

2. Pegmatite 4 feet thick, becoming thicker above; contains good mica.

3. Pegmatite 1 foot thick.

4. Pegmatite 30 feet thick; yielded much mica. 

5 and 6. Bulges in pegmatite. Schist roof over 5. 

7. Pegmatite 30 feet thick, pinching to 4 feet at 8.

25 50 too Feet

Tunnel A

N.25°east

Old shaft 46'ft 

rilled up { $

FIGURE 95. 1'lan and sections of Ridgeway Mica Co.'s mine at Ridgeway, Heury County, 

Va. A, Plan; B, longitudinal section looking S. 65" E.; C, cross section looking N. 25° 

E. See text for explanation of numbers.

Mining has revealed a pay shoot of mica pitching about 35°-40° S. 

25° W. in the body of the pegmatite. On the surface the pegmatite 

was traced about 250 feet S. 25° W. by prospect pits in which a little 

mica was found. Two pits 15 feet deep, about 400 feet south of the 

mine, opened mica-bearing pegmatite, but it is possible that these 

were not on the same vein.

The pegmatite consists of a fairly even mixture of feldspar, 

quartz, and mica. The feldspar is white albite and rarely occurs 

in crystals more than a foot thick. The quartz is the light smokygray variety and occurs chiefly in irregular masses, few of which
VIRGINIA. 325

are more than 2 feet thick. The largest crystals of mica are more 

than 2 feet in diameter, but many of them have the A structure 

strongly developed. A part of a mica crystal measuring 18 by 20 

inches and weighing about 42 pounds was presented to the United 

States National Museum by the Ridgeway Mica Co. This specimen 

has the A structure strongly developed on one side but has perfect 

cleavage over the full width of the crystal on the other side. Such 

a crystal would yield good sheet mica between the A lines. Crystals 

that would yield plates 12 by 20 inches were obtained during the 

summer of 1913. The mica has a light-smoky or brownish-green 

color and is classed as No. 1.

At the time of the visit 10 men were employed at the mine, 5 

below ground and 5 above, including two expert mica trimmers 

from Mitchell County, N. C. The interior of the trimming house 

is shown in Plate XXIX, B (p. 301). The clear flat sheets of mica 

on the bench come from the same crystals as the A mica, being split 

by the cutter in the foreground. The equipment includes a storage 

and trimming house, a boiler house, an engine and shaft house, a 

hoisting engine with bucket hoist, a steam drill, and a mine car. 

The Pittsburgh Mica Co. had a grinding mill near the site of the 

present trimming house, but this mill was burned down several 

years ago, and the scrap mica is now Shipped to mills in other 

places.

Another mica deposit was worked by the Pittsburgh Mica Co. 

about 250 feet S. 25° E. of the main mine. The workings were 

fairly large but are now rather inaccessible. The body of pegmatite 

was at least 30 feet thick in one part and was approximately conformable with the schistose diorite country rock. The feldspar of 

the pegmatite was considerably decomposed. The country rock 

was metamorphosed to biotite schist along the contact with the pegmatite. This mine is reported to have yielded good mica.

Several other mica prospects and mines have been opened on both 

sides of the road along the ridge northeast of the principal mine, 

on land belonging to the company. Most of these were discovered 

by Captain McCray. The deposits will be described in the order 

of their location northeastward from the main mine.

Good mica was found in sonie pits a few hundred yards north of 

the mine on the west side of the ridge.

Across the road and about 100 yards north of east of the mine two 

test pits had been made for feldspar in a semidecomposed pegmatite. 

Fairly fresh potash feldspar had been found at a depth of several 

feet. About 600 yards northeast another opening had been made 

for feldspar on semidecomposed pegmatite.

111375 23 22
326 MICA DEPOSITS OF THE UNITED STATES.

Two-thirds of a mile northeast of the mine a pit had been opened 

on mica-bearing pegmatite southeast of the road. Only small 

crystals of mica had been left around the prospect, and the sheets 

had a greenish cast. About 200 yards north of this prospect, on the 

northwest side of the road, a shaft had been sunk 27 feet on a promising vein, and good mica is reported to have been found. About 

60 feet southwest a mass of pegmatite, inclosing a 2-foot vein of 

quartz, crops out in a plantation road. Mica in sheets as much as 4 

inches across occurs in the decomposed feldspar along the southeast 

side of the streak of quartz.

About 1 mile northeast of the main mine and 100 yards northwest 

of the road a trenchlike open cut runs for 60 feet N. 60° E., and a 

25-foot shaft had been made on a body of mica-bearing pegmatite. 

This work was done by Captain McCray several years ago and is 

said to have yielded about $1,500 worth of mica. The pegmatite 

body is 6 feet thick in the end of the cut and is inclosed in schistose 

diorite. The feldspar of this pegmatite is chiefly albite. About a 

quarter of a mile to the northeast, 150 yards northwest of the road, 

Captain McCray sank another shaft about 30 feet deep on a promising deposit of mica.

About a quarter of a mile southeast of the prospect last mentioned, 

or 1£ miles northeast of the main mine, several shafts with short 

drifts had been made. These shafts were from 18 to 30 feet deep and 

cut decomposed pegmatite in schistose diorite. Some small crystals 

of mica having fine, smooth cleavage were found. This mica is 

somewhat specked and part of it may be classed as No. 2 stove and 

part as good electric mica.

Captain McCray has opened several other prospects in this region, 

in some of which he reports fairly promising mica veins.

The Ridgeway Mica Co. owns a feldspar quarry, from which several carloads of feldspar have been shipped, and other mica prospects 

on the same property about 2 miles south of Ridgeway.

KNIGHT PEOSPECT.

Several mica prospects, none more than 12 feet deep, have been 

opened on land now owned by H. A. Knight, 250 yards east of the 

railway station. These prospects are several years old. They fall 

within an area about 150 feet long measured N. 25° E. and 100 feet 

wide. The country rock is diorite cut by aplite and inclosing several 

bodies of pegmatite. In the last prospect opened the pegmatite was 

12 feet thick at the surface and 6 feet thick at a depth of 7 feet. The 

southeast wall of the pegmatite strikes N. 25° E. and has a vertical 

dip, and the northwest wall dips about 45° SE. Rough crystals of 

clear mica 6 or 8 inches across were found during prospecting.
VIRGINIA. 327

HENRY AND PITTSYLVANIA COUNTIES. 

GENERAL FEATURES.

Mica has been prospected and mined on a small scale at several 

places in the vicinity of Axton, Va., near the border of Henry and 

Pittsylvania counties. This region forms a part of the dissected 

Piedmont Plateau of Virginia and is similar in aspect to the Ridgeway country, already described. The elevations range from TOO feet 

above sea level in the valleys to more than 900 feet on the ridges.

The country rock of the Axton region consists of mica and garnet 

schist and gneiss and included beds of hornblende schist, all cut by 

granite and pegmatite. The strikes of the schists and gneisses 

measured were chiefly betAveen north and N. 30° E., but wide 

variations from these directions were noted. The dips are diverse.

TURNER MINE.

The C. S. Turner mine is on the summit of a hill about one-third 

of a mile N. 70° E. of Axton. It has been opened for about 100 

yards N. 25° E. by several shafts and pits^and by a trench at the 

southwest end. One shaft is reported to have been 40 feet deep. 

The pits ranged in depth from a few feet to 15 feet. The country 

rock is decomposed mica schist, cut by granite. The schist has an 

average strike of about N. 25° E. and a high dip to the east. The 

pegmatite occurs in overlapping lenslike masses, which are nearly 

conformable with the inclosing schist. Most of the mica is clear 

and rather dark green in sheets more than a sixteenth of an inch 

thick. Some of it is a little specked. A quantity of wedge and A 

mica crystals are obtained along with the good mica. Mr. Turner 

states that about 10,000 pounds of mica was removed from the trench 

and yielded about 500 pounds of sheet mica and 9,500 pounds of 

scrap. The largest mica would have cut into sheets measuring 6 by 8 

inches, but was sold for $2.50 a pound in the rough.

HARSTON MINE.

The David W. Harston mine is about 3^ miles north of Axton, 

near the foot of a hill having a slope of about 15° WSW. The 

workings consist of a shaft about 20 feet deep, a tunnel extending 35 

feet irregularly N. 60° E. from the shaft, and two small tunnels or 

gouges each about 6 feet across on the north and south sides of the 

shaft at about the same level as the main tunnel. A prospect pit had 

also been made about 30 feet north of the shaft. The position of the 

workings is shown in figure 96.

The country rock is mica schist cut by granite and pegmatite, 

partly decomposed to the depth of the workings. The schist near 

the mine strikes N. 60° E. and dips 35° SE. The body of pegmatite
328 MICA DEPOSITS OF THE UNITED STATES.

is very irregular in shape. The workings expose a mass of about 15 

feet thick in the bottom of the shaft with two branches forking out 

from it, one about parallel with the schistosity of the inclosing rock 

and the other cutting across it. These relations are shown in the 

cross section in figure 96. One arm of the pegmatite was opened 

by the prospect pit and the other was followed down by the shaft. 

Mica occurs in irregular-shaped bunches or pockets in the pegmatite, 

ranging from a few inches to more than 3 feet across, but a few 

crystals are scattered through the mass of the rock. Mica was rather 

plentiful in the 2-foot streak of pegmatite exposed in the shaft. The 

largest output was obtained from the tunnel. The minerals associated with the mica are partly decomposed potash feldspar, gray

smoky quartz,

Shaft

FIGURE 96. Plan and section of Harston mica mine, 3i miles 

north of Axton,. Henry County, Va. A, Plan ; B, cross section 

showing workings and geology.

and a little 

black tourmaline. One crystal of beryl 2 

inches in diameter was observed on the 

dump.

It is reported 

that about 11,000 

pounds of mica 

was shipped 

from this mine, 

from which possibly 2,000 pounds of sheet mica could have been obtained. The 

largest crystal weighed several hundred pounds. The mica is brownish green and rather heavily specked. Some of the crystals have been 

badly cracked and would yield only small plates, but others have a 

good smooth cleavage in large sheets.

About 250 feet S. 70° W. of the mine a mass of decomposed pegmatite 25 feet wide crops out in a road. Sheets of mica 3 inches 

in diameter were split from crystals found loose in the soil here. 

About 150 yards S. 80° W. a quantity of small sheet mica was plowed 

up in the light sandy soil of a cultivated field.

WILLIS MINE.

A mica deposit has been prospected on the land of L. C. Willis, 3 

miles north of Axton, by an 18-foot shaft, a short tunnel, and three" 

pits in a northeast direction. The workings fall within an area 75 

feet long and §0 feet wide. The country rock is mica and garnet 

schist. The pegmatite contains potash feldspar, which is partly de-
VIRGINIA. 329

composed; also a large streak of white quartz ranging in thickness 

from 2 feet in the shaft to about 6 feet a hundred feet to the southwest.

Only small mica was seen around the prospect, but larger and better 

material is said to have been carried away. Some of the small pieces 

examined have good cleavage, but larger rough sheets several inches 

across were less perfect. The mica has a dark-green color in thick 

sheets and some is a little specked. A specimen of sharply folded 

or crumpled mica was found at this prospect.

HOLLAND MINE.

Mica was mined or prospected at two places on the land of D. S. 

Holland, 2 miles north of Axton. Only one of these was examined. 

The workings consisted of a small open cut and a shaft 20 feet deep, 

filled with water. The country rock is schistose diorite and interbedded mica schist. The pegmatite is irregular in composition and 

grades into granitic pegmatite or coarse granite. Only small mica 

was seen at the mine, but about 2,000 pounds of better quality has 

been stored away. This mica is clear but rather dark green in thick 

sheets. Rectangular plates measuring 4 by 5 inches were seen at 

Mr. Holland's house.

PITTSYLVANIA COUNTY. 

GEORGE EASLY MINE.

A mica deposit was worked on the land of George Easly, 5 miles 

south by west of Chatham, first between 1900 and 1905 and again 

about 1910. The workings consist of a shaft about 40 feet deep and 

two open cuts connected with each other and with the shaft by a 60- 

foot tunnel and other underground work. When visited the mine 

openings were badly in need of repair.

The country rock is garnetiferous mica schist and gneiss, much 

folded and crinkled around the mica workings. The schist and 

gneiss have a general northeast to north by east strike and a variable 

southeasterly dip in the neighboring region. The body of pegmatite 

is approximately conformable with the main bedding of the inclosing rock, having an east of north strike and a southeast dip, but it 

cuts some of the smaller features of the structure. The pegmatite is 

not fully exposed, but it is more than 8 feet thick. It is about a 

normal granitic pegmatite, but contains no large segregations of massive quartz. The feldspar has partly kaolinized. Mica occurs in 

bunches of small wedge and A crystals or "capping" and in flat 

crystals of fair size with good cleavage. Partly clay-stained sheets 

of mica, 8 inches in diameter, with slight A structure, were seen
330 MICA DEPOSITS OF THE UNITED STATES.

around the workings. Three or four tons of scrap and mica suitable 

for small sheets and punching were left on the dumps and in an old 

shop at the mine. The mica has a clear, light apple-green color and 

good, smooth cleavage, but part of it is slightly specked.

WASHINGTON.

A mica deposit was discovered in 1897,98 near Chelan Falls, Wash., 

but it was not successfully developed. Eecently a deposit of micaceous material has been developed near Leavenworth, Chelan County, 

by the North American Ore Co. This is apparently a disintegrated 

mica schist and has been used chiefly in foundries for facing work.

WYOMING. 

GENERAL FEATURES.

Mica has been found in at least two places in. Wyoming, and 

other regions of pre-Cambrian rocks favorable to its occurrence 

are known. Prospects have been opened in the Hartville uplift, 

3 to 5 miles northeast of Ironton, in Laramie County, and in the 

Medicine Bow Range, in Albany County. Other areas of preCambrian rocks occur in the Front Range, in the Big Horn Mountains, in the Wind River Range, and near the northeast and the 

southwest corners of Yellowstone National Park. F. W. Clarke" 

mentions the occurrence of mica in the Wind River country.

ALBANY COUNTY.

In 1911 a mica prospect was opened by L. Learn in the Medicine 

Bow National Forest about 12 miles west of Fox Park, a station 

on the Colorado & Southern Railway, in Albany County. It is 

about 8,000 feet above sea-level. A quantity of mica was removed 

from a pit about 12 feet deep, sunk on a well-defined ledge of pegmatite. A sample of the mica sent to the Geological Survey was 

of fair quality.

A photograph was published by G. H. Lewis 10° showing a quantity 

of mica piled around a prospect in Albany County. This mica was 

obtained from a 20-foot shaft in a vein 9 to 20 feet thick. No 

name or location is given on the photograph, but the prospect is 

probably in the region mentioned above, and may be the same prospect.

M Colles, G. W., Mica and the mica industry: Franklin Inst. Jour., p. 48, 1006. 

90 U. S. Geol. Survey Mineral Resources, 1883 and 1884, pp. 906-912, 1885. 

100 Mill, and Bug. World, vol. 36, p. 289, 1912. .
WYOMING. 331 

LAKAMIE COUNTY.

The deposits in Laramie County were examined in 1906 by Sydney 

H. Ball,101 whose description is given below. They are in the rugged 

hills of the Hartville uplift, among which Haystack Peak is the 

most prominent and consist of pegmatite cutting the pre-Cambrian 

schists. These schists, which form the uppermost member of the 

older sedimentary series are closely folded and intensely metamorphosed near the granite of the Haystack Hills. The mica-bearing 

area lies east of Whalen Canyon and west of Cottonwood Canyon, 

and its north and south boundaries are respectively McCanns Pass 

and an east-west line passing through Haystack Peak. The possibly productive area includes all or parts of sees. 25, 26, 27, 34, 35, 

and 36, T. 28 N., R. 65 W., and sees. 1, 2, and 3, T. 27 N., R. 65 W.

The first mica claim, named the Savage, was located by Joseph L. 

Stein in 1881. Other prospects were soon taken up, and work has 

been done on some of them to the present day, but with an unimportant exception no muscovite has been shipped. At present four 

prospects appear promising.

Muscovite in commercial quantities is confined to dikes of pegmatite, which cut the schists. These dikes were intruded after the 

schist became fissile and in consequence trend in the main parallel to 

the schistosity, although in places they cut across it. The dikes vary 

from thin stringers to irregular intrusive masses a quarter of a mile 

wide. In many places their width is constant, but here and there 

it chaanges markedly within a short distance. The pegmatite is 

composed of the following minerals, named in the order of their 

abundance: Feldspar (orthoclase, microcline, and albite), quartz, 

muscovite (white mica), black tourmaline, beryl, brown garnet, and 

biotite. It is in general coarsely granular, the mineral bodies ranging in diameter from a quarter of an inch or less to 2 feet or more. 

Such extreme variations are rarely seen in a single dike, although 

considerable changes in the sizes of grains take place within comparatively short distances. The distribution of the minerals in the 

pegmatite is, as a rule, fairly even, although locally muscovite in 

particular occurs in bunches of books. Liquids and gases originating 

from the pegmatitic magma have considerably metamorphosed bands 

of schist on either side of the dikes.

The principal mica prospects of the Hartville uplift are the Crystal 

Palace, the Savage, the New York, and the Minnie.

The Crystal Palace claim, owned by Lauck & Stein, is on the south 

side of a steep valley in the center of the NE. £ sec. 34, T. 28 N., 

R. 65 W. An open cut 60 feet long has been made on a pegmatite

"» Mica in the Hartvillc uplift, Wyo.: U. S. Geol Survey Bull. 315, pp. 423-425, 1907.
332 MICA DEPOSITS OF THE UNITED STATES.

dike 6 feet wide at its floor and from 15 to 18 feet wide at its top. 

At the southwest end of the cut the pegmatite is covered by talus, 

but it is exposed for a long distance along its strike, which is 

N. 60° E. It is a coarsely crystalline aggregate of feldspar, white 

quartz, muscovite, tourmaline, brown garnet, and a little beryl. The 

black tourmaline is not prominent and is largely confined to the 

edges. Quartz was the last mineral of the pegmatite to solidify, 

and a portion of it was still held in solution by the magmatic waters 

after the pegmatite had consolidated, as it also occurs in indistinct 

veins which cut the pegmatite. The distribution of the muscovite 

is bunchy, and in consequence an estimation of the quantity of muscovite in the walls of the open cut is difficult, although it probably 

forms from 10 to ^.5 per cent of the pegmatite. The muscovite tends 

to form hexagonal plates, some of which are 2 feet across and 3 or 4 

inches thick. It is a good-grade " water " mica, although rulings 

are common, and in some of it plates of feldspar and quartz lie 

between the mica leaves. To the northeast across the gulch the pegmatite contains a greater proportion of tourmaline and beryl, and 

though muscovite is equally abundant, the plates are much smaller. 

At present there is 2 or 3 tons of mica on the dump. Some, of this 

is high-grade material which could be used for sheets.

The Savage claim, also the property of Lauck & Stein, is near 

the center of the S. £ sec. 26, T. 28 N., E. 65 W. An open cut is 

here located on a pegmatite dike 10 feet wide, which courses N. 65° E. 

About 200 feet farther southwest the dike either pinches out or 

plunges beneath the surface, and to the northeast it becomes narrower and the muscovite plates become smaller. The composition 

of this pegmatite is similar to that at the Crystal Palace claim, 

although bluish-green beryl is more abundant. In many places thin 

distorted crystals of tourmaline lie between the muscovite leaves. 

Muscovite in plates, some of them 12 inches in diameter,'forms 10 to 

15 per cent of the pegmatite. From this prospect sheets of mica 11 

by 13 inches and free from flaws have been obtained.

The New York claim is in the northeast corner of sec. 25, T. 28 N., 

E. 65 W., and is owned by Mr. Frederick. At the open cut the 

pegmatite dike is from 6 to 10 feet wide; it narrows to 5 feet 350 

feet to the west, but widens to 50 feet 500 feet farther west. The 

pegmatite varies considerably in the size of its constituent minerals. 

Muscovite occurs in plates as much as 20 inches in diameter, although 

the largest plates are commonly ruled. The larger flawless plates 

are from 6 to 8 inches in diameter.

The Minnie claim, southwest of the center of sec. 35, T. 28 N., 

E. 65 W., is also owned by Mr. Frederick. The largest sheets obtainable on this claim are 8 inches in diameter.
WYOMING. 333

Plates of mica 10 inches across were seen in a pegmatite dike in 

the north center of sec. 35, T. 28 N., R. 65 W. This dike is characterized by beryl crystals 4 feet long. Plates of muscovite 8 inches in 

diameter occur in a pegmatite dike in the center of the SE. £ sec. 35.

The pegmatite dikes in which large sheets of mica occur range in 

width from 5 to 18 feet and carry from 10 to 15 per cent of muscovite. 

It is probable that at least in the four prospects described, muscovite 

is present in commercial quantities. There is a marked variation in 

the width of the dikes along both the strike and the dip, and the size 

of the mica plates is by no means uniform in different portions of the 

same dike. The mica is clear and of good quality, although varying 

quantities of it are ruled, and feldspar, quartz, and tourmaline occur 

between the leaves of some of the books.

Mica mines in the Western States are operated at a considerable 

disadvantage on account of the high freight rates to the eastern 

market, which also prohibit the utilization of .feldspar and quartz, 

common by-products of mica mines, in the manufacture of pottery. 

These Wyoming prospects would furnish a considerable percentage 

of sheet mica for the glazing trade. Smaller plates could be used in 

making composite sheets of mica called mica board or micanite, and 

the waste mica could be shipped for grinding. The Crystal Palace 

and Savage claims can readily be reached by road, and the mica can 

be hauled to Ironton, Wyo., on the Chicago, Burlington & Quincy 

Railroad, for $1.25 a ton. The cost of transportation from the New 

York and Minnie claims would be somewhat greater. It is probable 

that under careful management mica of excellent quality could be 

produced in the Haystack Hills at a small profit.

INDEX.

A. Page. 

 A mica, aggregates of, with "wedge" mica,

plate showing.................. 18

crystal of, plate showing................. 18

cleavage plate of, plate showing.......... 18

formation of.../........,................ 16

" Abbs Creek ^'ine, N. C., description of...... 213

Adams mine, N. C., description of......... 201-203

Alabama, mines and prospects in............. 28-46

Alexandria, N. H., mines near.............. 149-151

Aley mine, N. C., description of............. 275

Alfred mine, N. C., description of.......... 179-180

Alger mine, N. H., description of............ 145

Amelia, Va., mines in the vicinity of........ 308-318

American Asbestos Co.'s mine, Va., description of......................... 318-319

American Mica mine, N. Mex., description of......................... 161-162

Anderson, Lovi, mine, Idaho, description of.. 89 

Anderson, S. C., prospect north of.......... 285-286

Andrews quarry, Conn., description of........ 69

Arizona, occurrence of mica in................ 46-47

Ashc, Bob, mine, N. C., description of........ 203

Auburn, Me., deposits near .................. 94

Avon, Idaho, deposits near................... 86-93

Axton, Vo., mines near.................... 327-329

B.

Bailey, L. J., kaolin and mica mine, N. C.,

description of.................... 228

Bailey Mountains, mine, N. C., description of. 276 

Baird mine, N. C., description of........... 224-225

Baird, Freeman, mine, N. C., description of... 219 

Bakersville, N. C., mines near.............. 245-249

Balsam Gap, N. C., mine near.............. 184-186

Bandana, N. C., mine near................... 250

Barnard, N. L.,mines, N. C., description of. 237-238 

Barnes, S. C., prospects near.............. 283-284

Bascommine, N. C., description of........... 244

Batchellerville quarry, N. Y., description of.. 166 

Baxter, Frank, mine, N. C., description of.... 221

Baxter, Thomas, m inc,N. C., description of 220-221 

Beam Mill, N. C., prospects near............ 189-190

Bear Pen mine, N. C., description of.......... 239

Bearwallow Fork mine, N. C., description of.. 213 

Bcasley mine No. \, N. C., description of.... 231-232

No. 2, N. C., description of.............. 232

Beaver Creek, N. C., mines near........... 173-176

Beck mine, Ga., description of................ 85-86

Bedford City, Va., mine southeast of....... 318-319

Bee Tree Fork mine, N. C., description of... 265-266 

Beech Hill mica mine, Maine, description of. 99-100 

Beldon mine, east of Canaan, N. H., description of......................... 136-137

view across open cut of, plate showing.... 109

Belden mine, near West Rumnoy, N. H,

description of.................. 121-122

Page.

Bennett prospect, Maine, description of....... 95

Bennctt, David, prospect, Ga., description of. 75 

Berry mica and kaolin mine, N. C., description of........................... 229

Berry mine, Va., description of.............. 317

Berry's, Mrs. I. T., mine, Ala., description of. 44 

Beryl, largest crystals of, where found....... 145

Bess mine, N. C., description of.............. 223

Beta, N. C., prospects near................ 199,201

Bibliography................................ 1-3

Big Flint mine, N. C., description of......... 197

Big Jumbo mine, N. C., description of..... 266-267

Big mine, Ga., description of................ 83

Big Ridge mine, N. C., description of........ 194

Bigger Mine, Colo., description of............ 57-58

Biotite, occurrence of........................ 7

properties of............................. 11,14

sheet of, inclosing a rhombic crystal of

muscovite, plate showing........ 19

Black Hills, S. Dak., geology of............ 289-292

Black Mountain, N. C., mines on or near.. 209-210 

Black Mountain station, N. C., mines near. 186-188 

Black Mountain mica mine, Maine, description of........................... 98-99

Blaine, C. T., mine, N. C., description of.... 226

Blalock mine, N. C., description of.......... 258

Blanton prospects, N. C., locations of...... 191,192

"Book" of mica, use of term................. 15

Boono, N. C., mines near.................... 270

Boonford, N. C., mines near........... 250,275-276

Bowers mine, N. C., description of........... 204

Boyd, C, H., prospects, Ala., description of.. 37 

Boyd Knob mica and kaolin mine, N. C,,

description of.................... 231

Bradley butt, N. C., description of......... 231-232

Brandy wine Summit, Pa., deposit near...... 281

Brooks prospect, N. H., description of....... 118

Brown, Albert, prospect, N. C.,.description

of.............................. 2L9-220

Brown's Coward Mountain prospect, N. C.,

description of.................... 211

Brown's, Mrs. Susan, prospect, N. C,, description of...................... 219

Brown Mountain, N. C., prospects on....... 265

Brushy Mountain mine, N. C., description of. 187 

Bryson mica and kaolin mine, N. C., description of........................... 232

Bryson, C. D., mine, N. C., description of... 207 

Bryson, Neal, mine, N. C., description of.... 233

Bryson, P. N., prospect, N, C., description of. 215 

Buchannan mine, N. C., description of...... 249

Buckhorn mine, Colo., description of........ 59-60

Buckley mine, N. H., description of......... 147

Burkmont prospect, N. C., description of.... 188

Burnett, W. H., mine, N. C., description of. 187

335
336 INDEX.

Page.

Burningtown mine, N. C., description of... 238-239 

Burnsville, N. C.,minenear................. 279

Burtonsville, Md., prospect near............. 104

Burwell, Ga., deposits northwest of......... 71

Buzzard Roost Knob prospect, N. C.; description of........................... 188

C.

Cabaniss, Tom, mines, N. C., description of.. 192 

Cabe mine, N. C., description of............. 228

California, prospectsin...................... 47-49

Camp Mountain mica and kaolin mine, N. C.,

description of.................... 220

Campbell mine, Ala., description of.......... 36

Campbell mine, N. C., description of....... 230-231

Canaan, Conn., prospect in.................. 65

Canaan, N. H., mines near................ 133-138

Canada Township, N. C., mines and prospects

in......................... 216,219,220

Cany Fork, N. C., mines near mouth of.... 213-214

" Capping" of mica, plate showing........... 18

Carolina Mineral Co.'s mines, N. C., description of......................... 252-254

views toward, plates showing............ 260

Carpenter, Calvin, mine, N. C., description

of............................. 189-190

Carpenter, Mauney, prospect, location of.... 193

Casar mine, N. C., description of............. 191

Cathance, Me., deposit near................. 101

Cattail Branch mine, N. C., description of... 277 

Cedar Cliff mine, N. C., description of....... 210

Celo, N. C., mines near................ 276,277,279

Center StrafTord, N. H., mine near........ 156-158

Chalk Hill mine, N. C., description of....... 238

Chalk Mountain mine, N. C., description

of............................. 257-258

Chambers, A. A., analysis by................ 47

Champion mines, Va., description of....... 310-313

Champion No. 2 mine, Va., surface 'equipment of, plate showing.......... 301

Chapman mine, Ga., description of.......... 75

Charlies Ridge mine, N. C., description of... 182-183 

Chastine Creek mine, N. C., description of. 212-213 

Chatham, Va., mine southwest of.......... 329-330

Cherry Mountains, N. C., prospect on....... 263

Chester Heights, Pa., deposits near........ 280-281

Chestnut Mountain mines, Va., description

of...:.......................... 319-320

Chestnut Ridge mine, N. C., description of.... 266

Chink Knob prospect, N. C., description of. 216-217 

Clarissa mine, N. C., description of........ 245-247

Cleavage of the micas........................ 14

Climax mine, S. Dak., description of........ 301

Cloudland mine, N. C., description of...... 247-24R

Glower, T. R., prospect, Ala., description of.. 45-46 

Cockeysville, Md., deposit near.............. 102

Cole, M. M., prospects, Qa., description of... 73 

Color in mica................................ 14,17

Colorado, mines and prospects in............ 49-62

Columbian Gem Mining Co., prospect of,

N. H.......................... 152-153

Connally mine, N. C., description of....... 186-187

Connecticut, mines and quarries in.......... 62-70

Cook, Ethan, mine, N. C., description of..... 196

Cook, W. J.. mine, Ga. descriotion of........ 74-75

Page.

Corundum Hill mica mine, N. C., description of........................... 227

Council, Idah o, deposit southeast of.......... 93

Coward Mountain, N. C., mines on......... 210-211

Cowee Mountains, N. C., mines along........ 227

Cox & Davies mine, N. C., description of.... 203

Craft, J. W., prospect, Ga., description of.... 77

Craig prospect, N. H., description of......... 129

Cribben mine, N. Mox., description of..... 159^161

Crown mine, S. Dak., description of....... 297-299

end of small dike of pegmatite at, plate

showing......................... 300

Crystal Palace claim, Wyo., description of. 331-332 

Crystallography of the micas.:............... 11-14

Cullowhee, N. C., mines near.............. 203-205

Curley mine, Ala., description of............. 34

Custer, S. Dak., mines in the vicinity of... 292-302

D.

Davidson, R. M., mine, N. C., description of 187 

Davis mine, N. H., description of.......... 109-110

Davis, Charles, mine, N. H., description of. 129-130 

Davis, E. D., prospect, description of........ 201

Daybook, N. C., mines near.............. 277-278

Deake mine, N. C., description of............ 256

Deal, I. A., prospect, N. C. description of... 244 

Dean, E. W., prospect, Ga., description of... 83 

Deerlick Gap mine, N. C., description of..... 227

Do Lay prospect, Ga., description of......... 72

De Mott mine, N. H., description of......... 146

Denver Mining and Manufacturing Co., operations by......................... 50

DiUinger, John, mines, N. C., description of.. 223 

Distribution of mica in the United States.... 4

Dobbins mine, N. C., description of.......... 269

Dobson mine, N. C., description of........ 243-244

Dorchester, N. H., mine in................ 133-134

Doublehead mine, N. C., description of...... 179

Duncan mine, N. C., description of.......... 176

Dyer, B. E., prospect, Ga., description of.... 83

 E. 

Earth Products Co., mines of, Md........... 104

Easly, George, mine, Va., description of... 329-330 

EastAlstead, N. H., mines and prospects

near........................... 107-109

East Glastonbury quarry, Conn., description

of................................ 70

East Laport mine, N. C., description of...... 213

Eastman prospects, N. H., description of.. 127-128 

Edgar Bros, kaolin and mica mine, N. C., description of.................... 255-256

Electric mica, grade of....................... 26

Electrical apparatus, use of mica in...... 19,22,24

Elk Crossroads, N. C., mines near..... 176-177,269

Ellis, E. R., mine, N. C., description of...... 191

Elmore mine, N. C., description of........... 228

English, Milton, mine, N. C., description of. 180-181 

Evans mine, N. C., description of......... 240-241

Evans, B. W., prospect, Ga., description of.. 77

F. 

Fallston, N. C., mines near.V...... 189,193,221-222

Feldspar, occurrence of, in pegmatite........ 6

Ferguson, Judge, mine, N. C., description

of.-........................... 205-208
INDEX. 337

Page. 

Firestone mine, S. Dak., description of...... 300

face of open cut in, plate showing........ 300

" Fishbone" mica, crystals of, plates showing. 18 

cleavage plates of, plate showing......... 18

features and use of...................... 16

Fisher's feldspar quarry, Maine, description

of............................. 100-101

Flat Rock mine, N. C., description of...... 250-251

Fletcher mine, N. H., description of....... 125-127

Forest, Richard, prospect, N. C., description

of............................... 265

FoSs mine, N. H., description of........... 156-158

Foster mine, N. C., description of........... 173

Foster, Arney, mine, N. C., description of... 270 

Foster, William, prospect, Ala., description

of............................... 39

Fox mine, N. C., description of.............. 228

Fox Park, Wyo., prospect west of........... 330

Frady Creek mine, N. C., description of... 212-213 

Franklin, N. C., mines near.............. 224-226,

227-231,232-238,243-244 

Eraser & English prospect, N. C., description of........................... 190

French mine, N. H., description of........ 113-114

view across open cut of, plate showing...' 108 

Frotwell prospects, S. C., description of.... 283-284

G.

Caddis -mine, -Ga., description of............. 80

Gage mine, N. H., description of.... '........ 146

Gaillard mine, S. C., description of........ 282-283

Galesburg mine, S. Dak., description of.... 301-302

Galloway, A. E., mine, N. C., description of.. 220 

Garnets, flattened, in sheet of mica, plate

showing......................... 19

occurrence of, in mica................... 18

Geering, Philip, prospect, S. Dak., description of........................... 302

tourmaline in pegmatite exposed at, plate

showing......................... 300

Gem minerals, occurrence of................. 56,

63-69,77,80,94,95,97,113,125,130, 

152-154,158,171,176,177,188,215, 

216, 278, 279, 285,308-310,317,322 

General Electric Co.'s mine, N. H., description of........................ 118-121

fork in the pegmatite at, plate showing.. 108 

Georgia, mica deposits of, map showing location of.......................... 72

mines and prospects in.................. 70-86

Gibbs Lubricating Co.'s prospects, Ala.,

description of................... 42-43

Gibbs mine, N. C., description of.......... 273-274

Gilkey, N. C., prospects near................ 263

Gillette, M. P., quarry, Conn., description of. 67-69 

Gilmore mine, Md., description of......... 104-105

Gilsum, N. H., mines near................ 109-116

Glass mine, N. C., location of................ 187

Glenn's, D. M., mine, N. C., description of... 279 

Globe mica mine, N. Hex., description of.. 162-163 

Globe mine, N. H., description of........... 156

Gold, W. F., mine, N. C., description of..... 193

Gooch, Matt, .mine, Ga., description of....... 82

Goodman mine, N. C., description of........ 176

"Gophering," meaning of................... 20

Grades of mica.............................. 26

Page. 

Grady mine, Colo., description of............ 61-62

solid mica exposed at, plate showing..... 62

Grafton, N. H., mines in or near... 138-149,151-154 

Graf ton Mica Works, N. H., mine of....... 138-139

Graham mine, Ga., description of............ 80

"Granite, graphic," nature and occurrence of. 7

graphic, plateshowing................... 18

pegmatitic, outcrops of, in the Black

Hills, S. Dak., plate showing.... 261 

Granite StateMicaCo. 'smine, description of. 108-109

view across open cut of, plate showing... 108 

GrcatNorthernmine,S.Dak.,descriptlonof. 299-300 

Great Southern Mica Co.'s mines, Ala....... 30-33

Green, C. C., prospect, N. C., description of.. 270 

Green, Gibbs M., mine, N. C., description of. 250 

Green, Locke, mine, N. C., location of....... 269

Green, S. J., mine, N. C., description of.... 190-191

Green Mountain, N. C., mine near......... 276-277

Green Vein mine. Ga., description of........ 81-82

Greenville, S. C., mine southeast of........ 286-288

Gregory mine, N. C., description of........ 203-204

Grimshawe^ Thomas, mine, N. C., description

of............................... 216

Grinding of mica, processes of............... 22-23

Ground mica, uses of...................... 19,24-26

" Groundhogging," meaning of.............. 20

Gustavino mine, N. C., description of...... 187-188

H.

Haddam Neck quarry, Conn., description of. 67-69 

Haile mine, N. H., description of............ 147

Hailey, J. A., prospect, Ga., description of... 77 

"Hair-lined" mica, use of name............. 15,16

Halberg, Joseph, quarries, Conn., description

of............................... 69

Hall mine, N. C., description of............ 233-234

Hambrick, E. C., mine, N. C., description of. 191 

Hamilton mine, N. C., description of...... 173-174

Harris Clay Co.'s mines N.C.,descriptionof. 254-255

Harris workings of, view showing........ 260

Harris mine, N. C., description of............ 176

Harston, David W., mine, Va., description

of............................. 327-328

Hartford mine, N. H., description of....... 130-133

Hartwell, Ga., prospects near................ 77-78

Hauser mine, N. C., description of......... 271-273

Hawk mine, N. C., description of............ 245

Hawkins, Joe, mine, N. C., description of.... 263

Haystack Peak, Wyo., prospects near..... 331-333

Haywood Gap, N. C., mine near............ 196

Heaton, J. S., prospects, Ga., description of.. 77 

Heavner, D. C., mine, N. C., description of. 223-224 

Hendricks, N. C., mine near................. 271

Henry, Jacob W., mine, N. C., description of. 226 

Henry, N. C., mines near.................. 188,223

Hensley mine, N. C., description of........ 276-277

Herbert prospects, N. H.: description of..... 122

"Herringbone" mica. See " Fishbone " mica. 

Hewlett, Va., mines south of............... 321-322

Hibbs mine, Maine, description of........... 95-96

Hickory, N. C., prospect southwest of........ 188

Hicks Pond prospect, Maine, description of. 95 

Hieroglyphic mica, plate showing........... 19

use of name.............................. 18

Higdon mine, N. C., description of......... 230-231
338 INDEX.

Page. 

Higdonville, N. C., mine near................ 226

highlands, N. C., mines near................ 244

Hill, Joe, mine, N. H., description of....... 154,155

Hillhouse, J. D., mine, Ga., description of.... 73

Hodges, W. L., prospect, Ga., description of.. 77 

Holbrook mine, N. C., description of......... 225

Holden mine, N. H., description of........... 129

Hole mine, N. C., description of............ 263-265'

Holland mine, Va., description of............ 329

Hollofleld, Md., deposit near................. 102

Holmes, C. L., prospect, Ala., description of.. 38 

Holmes, J. A., cited............ 49,160,161,246-247

Hooper, Leon, mine, N. C., description of.. 209-210 

Hope, George M., mine, Ga., description of... 76-77 

Horses, occurrence of, in pegmatite........... 6

"Horsetail" mica, use of name............... 16

Houser, Plato, mines, N. C., description of. 222-223 

Howe, Lewis W., quarry, Conn., description

of................................ 70

Hoyt Hill mine, N. H., description of...... 137-138

Hull, M. M., mine, N. C., description of...... 223

I. 

Idaho, mines and prospects in............... 86-93

timber in mica region of................. 93

Imports of mica............................. 28

India Mica Co.'s mine, N. H., description of. 133-134 

Indian Town mine, N. C., description of...... 191

Inez, N. C., prospects near................... 268

International Mica Co.'s prospects, Va., description of...................... 316

lotla Bridge kaolin and mica mine, N. C.,

description of.................. 234-236

lotla mine, N. C., description of.............. 237

Irwin mine, Va., description of............. 320-321

Isinglass Hill mine, N. C., description of.... 261-263

Isinglass Mountain, N. H., deposits on or

near........................... 138-144

Island Ford mine, N. C., description of....... 214

Island mine, N. H., description of.......... 111-113

Iva, S. C., mines west of................... 284-285

J. 

Jacobs mine, N. C., description of.......... 236-237

Jasper, Ga., prospects near................... 84

Jefferson, N. C., mines near................ 172-173

Jefferson mines, Va., description of......... 310-313

Johns Creek, mines near junction of, with

Cany Fork, N. C.............. 211-212

Johnson mine, N. C., description of......... 181-182

Johnston mine, N. C., description of.......... 226

Justice mine, N. C., description of........... 183

Kaolin, from Isinglass Hill mine, N. C., analysis of... ........................ 262

See also descriptions of mines, especially in

North Carolina.

Kasson Mica Co.'s mine, Pa., description of. 279-280 

Kasson Mining Co.'s mine, N. C., description

of............................... 225

Keene Mica Products Co.'s mine, N. H., description of.................... 114-115

enrichment of mica in pegmatite in, plate

showing......................... 108

view from north side of open cut of, plate

showing......................... 108

Kell mine, Ga., description of................ 86-

Keller's, Mrs., mine, N. C., description of.... 20*

Kensington, Md., mine near............... 104-105

Keyes mine, N. H., description of......... 134-135

Keystone Mica Co.'s mine, Va., description

of.............................. 317-318

Kilton, M. M., mine, N. H., description of.. 143-144 

view in open cut of, plate'showing....... 108

Kilton, M. M., Eureka mine of, N. H., description of....................... 144

Kings Mountain, N. C., prospects near..... 193-194

Kinkel quarry, N. Y., description of......... 166

Knight prospect, Va., description of......... 326

Knob mine, N. C., description of.......... 260-261

Knoff mine, Ala., description of............. 36

Knutt mine, Ala., description of............. 3S-3&

La Grange, Ga., deposits near............... 86>

Ladder Canyon, Colo., deposit in............ 61-62:

LaMn prospect, N. H., description of...... 107-108

Landers & Ayres prospect, Ala., description

of................................ 37

Lattimore, N. C., prospect east of............ 193-

Laurel, Md., prospects northwest of....... 102-103

Lazulite, unusual'occurrence of.............. 130-

Learn prospect, Wyo., description of........ 330

Ledford mine, N. C., description of.......... 227'

Lee, Eph, mine, Ga., description of.......... 81

Lee, Henry, mine, Ga., description of........ 81

Leichtle, Moritz, acknowledgment to........ 159

Leroy prospects, S. C., description of........ 288

Letterman mines, N. C., description of.... 277-278

Linney, F. A., mine, N, C., description of.... 270

Little Jumbo mine, N. C., description of..... 267

Little Phoenix mine, N. C., description of.. 172-173 

Long, John, mines No. 1 and No. 2, N. C... 206-207 

Long Mountain mine, Ga., description of.... 82

LostBonanza mine, S. Dak., description of. 300-301 

Lovedahl, A. L., prospect, N. C., description

of................................ 212

Luella mine, Idaho, description of........... 93

Lyle Cut, N. C., description of............. 240-241

Lyle Knob mine, N. C., description of....... 230

M. & G. Co.'s mine, Ala., description of...... 40-41

McChone, Z. T., mines; N. C., description of.. 258 

McConnell prospect, S. C., description of... 285-286- 

McCoury prospect, N. C., description of...... 184

McCracken mine, Ga., description of......... SS'

McCray prospects, Ala., description of....... 44-45

McDoiiogh, Md., deposit near................ 102

McGinnis arid Whicher & PUlsbury prospect,

N. H., description of............. 123

Mcliidoe, Hugh, mines, Ala., description of.. 33 

Mclnnish, N. M., prospects, Ala., description

of................................ 39

McKiimey mine, N. C., description of..... 183-184

McNamara mine, Ala., location of........... 41

Magnetite, mica specked with, occurrence of. 17-18 

mica "specked" with, plate showing.... 18

Maidens, Va., mines northwest of.......... 320-321

Maine, mines and prospects in.............. 94-101

Marshall mines, Va., description of........ 316-317

Maryland, mines and prospects in......... 101-105
INDEX. 339

Page. 

Maryland Mica Co., mining by............ 102-103

Massachusetts, deposits in................... 105

Masters mine, Ga., description of............ 80

Mauney, M. M., mine, N. C., description of.. 190 

May, J. Warren, mine, Ala., description of.. 42 

Maybe mine, Idaho, description of........... 92-93

Meadows mine, N. C., description of....... 177-179

view toward, plate showing.............. 171

Media, Pa., mine west of.................. 279-280

Melvin Hill, N. H. See Springfield Mountain, N. H. 

Metamorphism, rocks resulting from......... 4-5

"Mica capping," use of term................. 7-8

Mica City, N. C., mines near............... 231-232

Mica Hill, Colo., deposits in................. 55-56

Mica Products Co.'s mine, N. H., description

of................................ 130

Micanite region, Colo., mines in.............. 51-55

Micaville, N. C., mine near.................. 275

Middle Old Field prospect, N. C., description

of.............................. 196-197

Mill Knob mines, N. C., description of..... 228-229

Miller mines, Ala., description of............ 35

Miller prospect, N. C., description of......... 184

Mills quarry, Maine, description of........... 97

Mineralogy of mica.......................... 11-18

Minerals found in pegmatite................. 8

Mines, descriptions of....................... 28-333

Mining of mica, disadvantages of, in the

Western States.................. 333

history of................................ 19-20

methods of.............................. 20-21

Minnie claim, Wyo., description of.......... 332

Monarch mine, N. H., description of......... 150

Montana, deposits in........................ 105

Montreat, N. C., prospects near.............. 188

Montvale, N. C., mines near............... 266-268

Moore mine, N. C., description of............ 226

Mora, N. Mex., deposits near.............. 158-159

Morganton, N. C., prospects near............ 188

Morning Star claim, Idaho, description of.... 92

Morning Star mine, N. C., description of..... 267

Morris, T. E., prospect, Ga., description of... 78 

Motes, J. B., prospects, Ala., description of.. 39-40 

Mount Alamo Mining Co., operations of...... 48-49

Mount Apatite, Maine, deposits in........... 94

Mount Ararat feldspar quarries, Maine, description of..................... 100

Mount Mica, Maine, deposit in............... 97-98

Mud mine, N. H., description of............. 149

Murphy, Ben, mine, Md., description of..... 104

Murphy prospects, N. H., description of... 155-156 

Muscovite, occurrence of..................... 7

properties of............................. 11,14

rhombic crystal of, inclosed in biotite,

plate showing................... 19

Muscovite mine, Idaho, description of....... 89-92

N. 

Neddie Knob, N. C., prospects on........... 219

Nelson, Ga., prospects near.................. 83-84

Nevada, deposits in....................... 105-106

New Balsam Gap mine, N. C., description of......................... 184-186

New Hampshire, mines and prospects in... 106-158 

mines and prospects in, map showing.... 108

-JJew Haven Mica Co., mine of, N. H....... 149-150

Page. 

New Jersey, prospect in..................... 158

New Mexico, deposits end prospects in.... 158-165

New York, deposits in.................... 165-166

New York claim, Wyo., description of...... 332

Now York mine, S. Dak., crystals of mica at,

plate showing................... 294

description of.......................... 292-295

view, along pegmatitic outcrop at, plate

showing......................... 300

view toward, plate showing............. 261

Newdale, N. C., mines near................ 273-275

Nicholson, Andy, mine, description of....... 211

Nickelson, W. J., mine, description of..... 267-268

Nims mine, N. H., description of........... 116-117

Norfleet mine, Va., description of............ 318

North Carolina, distribution of mica in..... 168-170

history of mica mining in.......... 167-168,172

minerals associated with pegmatite in. 170-171 

mines and prospects in................ 172-279

mode of occurrence of mica in........... 170

production of mica in.................. 171-172

western, map showing location of mines

and prospects in................. 170

North Groton, N. H., mines near, description

of............................. 124-133

North Hardin mine, N. C:, description of.. 174-175 

view in stope of, plate showing.......... 170

0. 

Ocala, N.C., mines near................... 215-216

Occurrence of mica, mode of...... 4,7,14-15,18,170

Ocher Hill mine, N. C., description of....... 199

Ojo Caliente, N. Mex., prospects near...... 163-164

Old Dean Mica mine, Ga., description of.... 72-73

Old Mike mine, S. Dak., description of..... 299-300

Old Scott mine, Ga., description of.......... 82

Orange, N. H., mines in and near..... 134-135,138

Oswegatchie, N. Y., prospect near......... 165-166

P. 

Painter mine, N. C., description of........ 199-200

Palermo mine, N. H., description of....... 130-133

view down into the stopcs of, plate

showing......................... 108

Panther Knob, N. C., mines near.......... 203-205

Parham, Earl," prospect, Ga., description of. 78 

Parkson & Kitchen's prospect, Colo., description of...................... 60-61

Parlct prospect, Md., description of.......... 103

Parson mine, N. H., description of.......... 108

Patten mine, N. H., description of........ 150-151

Pattcrson mine, Va., description of........ 315-316

Peacock prospect, N. Mex., description of... 163 

Pegmatite, con stituents of................... 6

contact of, with gneiss at Fircstonc mica

mine, plate showing.............. 300

end of small dike of, plate showing...... 300

fine-grained contact of, plate showing.... 171

" genesis of................................ 8-11

inclosed in mica gneiss, open cut in, plate

showing......................... 62

irregularities in bodies of................ . 5-6

mica crystals in and blasted loose from,

plate showing................... 300

minerals found in........................ 8

occurrence of............................ 4,5-8

size of deposit of, workable for mica..... 6
340 INDEX.

Page. 

Pendleton, S. C., prospect southeast of...... 286

Penland, N. C., mines near........ 250-251,252-256

Pennsylvania, mines and prospects in..... 279-281

Percussion figures, mode of obtaining and form

of............................... 12-14

on cleavage sheet from mica crystal, plate

1 showing......................... 18

Petaca, N. Mex., prospects near............. 164

Petty, M. J., prospect, Ga., description of... 83 

Phillips mine, Ala., description of........... 34-35

Phlogopite, properties of.................... 11,14

Pinchbeck mines, Va., description of...... 314-315

Piney Mountain mine, N. C., description

of.............................-197-198

Pingree prospect, Maine, description of...... 95

Pinhook Gap mine, N. C., description of.. 218-219 

Pitner Mica Co., operations by..... 78-80,81,82-83

Playter mica and beryl mine, N. H., de- ,

scription of.................... 153-154

plate showing........................... 108

Plott Balsam Mountain, prospect on...... 195-196

Plumtree, N. C., mines near............... 177-184

Plumtree mine, N. C., description of......... 181

Poll mil mine, N. C., description of....... 274-275

Poll Miller mine, N. C., description of..... 238-239

Powdermill Creek mine, N. C., description

of............................. 183-184

Preparation of mica for the market.......... 21-23

shops for, .plates showing.............. 170,301

Presley, L. C., mine, N. C., description of.. 204-205 

Pressure figures, directions of rays of, compared with directions of ruling 

planes........................... 15

mode of obtaining and form of........... 12-14

Price, J. B., mine, N. C, description of.... 211-212

Price prospects, N. H., description of........ 117

Pritchard prospect, N. C., location of........ 184

Production of mica.......................... 26-27

Properties, physical, of the micas............ 14-18

Putman, Sam, mine, N. C., description

of.......................... 191-192,193

Pyatt mine, N. C., description of............ 183

QQuartz, occurrence of, in pegmatite.......... 6-7

Queen, Lewis, mine, N. C., description of.... 212

Quizzenbeny mine, N. C., description of.. 227-228

R.

Baby-Sweet mine, N. C., description of...... 237

Randall mine, N. C., description of.......... 249

Randolph Mica Co., mines of, Ala........... 38-39

Ray mine, N. C., description of.............. 279

Reece, James, mine, N. C., description of.... 219

Reece, J. F., mica and beryl on land of...... 188

Reece, Mark, mine, N. C., description of..... 198

Reed mine, N. C., description of............. 266

Reed mine, Va., description of.............. 321

Reepsville, N. C., mines southwest of..... 223-224

Reynolds beryl and mica mine, N. H., description of.................... 151-152

Rhoda mine, N. H., description of......... 110-111

mica crystals in a face of pegmatite in,

plate showing................... 108

view across main open cut of, plate showing.............................. 108

Page. 

Ribera, N. Mex., prospects near........... 164-165

Ribbon mica. See Ruled mica.

Rice mica and beryl mine, N. C., description

of.............................. 214-215

Rice, Jake, mine, N. C., description of....... 215

Rich, J., mine, N. H., description of......... 151

Rich Mountain, N. C., mines near......... 212-213

Richland Balsam Mountain, mines near..... 195

Ridgeway, Va., mines near................ 322-326

Ridgeway Mica Co.'s mine, Va., description

of.............................. 323-326

interior of mica-trimming house at, plate

showing......................... 301

Rioville, Nov., deposits east of............ 105-106

Roaring Brook quarry, Conn., description of. 69-70 

Roaring Creek, N. C., prospects near........ 184

Roaring Fork mine, N. C., description of.... 243

Rochester, J. H., mine, N. C., description of. 216 

Rock mine, N. C., description of.......... 208-209

Rocky Mount, Va., mines southeast of.... 319-320

Roda kaolin and mica mine, N. C., description of......................... 213-214

Roebling,., George, mine, Conn., description

of................................ 63-65

Rowe mine, Colo., description of............ 55

Royal Gorge region, Colo., prospects in...... 55-50

Royster, J. H., mine, N. C., description of... 193 

Ruby City mine, N. C., description of....... 198

Ruggles mine, N. H., description of....... 139-143

Ruggles New Hill mine, N. H., description of 139 

Ruled mica, mode of formation of............ 15-16

plate showing........................... 18

Ruthertbord mine, Va., description of..... 308-310

Rutherfordton, N. C., mines near........... 26-263

S.

Sain mine, Ga., description of............... 79

St. Louis mine, S. Dak., description of....... 301

San Miguel Mica Co., claims of, N. Mex... 164-165 

Sanborn mine, N. H., contact between pegmatite and overlying gneiss at, 

plate showing................... 109

description of.......................... 135-136

Sanders, Doc., kaolin mine, N. C., description

of................................ 229

Sandy Ridge, N.C., mines near........... 263,265

Sapphire, N. C., mine near................ 214-215

Saunders, C. W., mines, Va., description of 321-322 

Saunders Hill prospects, N. H., description

of............................... 123-124

Savage claim, Wyo., description of........ 331,332

Scaggsville, Md., deposits near............. 102-104

Schlegel mine, Va., description of............ 318

Seneca, S. C., prospects northeast of......... 288

Sericiteschist,analyses of................... 47,84

Sheep mountain, N. C., prospect on......... 210

Sheep mountain mine., N. C., description of. 209 

Shelby, N. C., mines west and northwest of 190-193 

Sherard mine, S. C., description of........... 285

Shining Rock mountain, N. C., prospects

near........................... 196-197

Shiny mine, N. C., description of............ 195

Sink Hole mine, N. C., description of........ 250

Smith, C.D.,cited........................ 224-225

Smith, T.W., analysis by................... 262

Smith mine, N. C., description of.......... 224-225
INDEX. 341

Sol Creek, N. C., mine below mouth of....... 214

Solid mica, blasted loose from pegmatite,

plate showing................... 63

consisting of wedge and A mica, plate

showing......................... 18

exposed at Grady mine, Mesa County,

Colo., plate showing............. 62

use of term.............................. 7,8

Sources of information on mica deposits...... 1

Sourwood Gap prospect, N. C., description of 224 

South Carolina, mines and prospects in.... 281-288

South Dakota, mines and prospects in..... 289-302

South Hardinmine, N. C., description of.. 175-176 

Southford quarry, Conn., description of...... 70

" Specked" mica, meaning of................ 17-18

plates showing........................... 18

Spence prospect, N. C., location of........... 205

Splitting of mica, process of............... 15,21-22

Springfield, N. H., mines in or near........ 153-156

Springfield Mountain, N. H., mines on.... 151-154

Spruce Pine, N. C., mines near........ 254,256-261

Spruce Ridge mine, N. C., description of..... 195

Stalcup, Ruth, mine, N. C., description of... 239 

Stamey, Joe, mines, N. C., description of.... 222

Standard mine, N. H., description of...... 136-137

view across open cut of, plate showing... 109 

Starr, S. C., mines west of............. 282-283,284

Steele mica mine, N. C., description of....... 265

Stinson prospect, N. H., description of....... 129

Stony Fork, N. C., mines near............. 269-270

Stove mica, grade of......................... 26

Strickland, F. E., quarry, Conn., description

of................................ 65-67

Sugarloaf Mountain, N. C., prospects on and

near................... 197-199,208-209

Sullivan, N. H., mines near................ 116-118

Summit Mica Mining Co., N. H., prospect of. 138 

Sunshine claim, Idaho, description of........ 92

Survey prospect, N. C., description of........ 261

Swannanoa, N. C., mines near............... 187

Sylva, N.C., mines east of................. 199-201

T.

Tallapoosa Mica Co., mines of, Ala........... 43

Tallow Face mine, N. C., description of...... 267

"Tangle-sheet" mica, meaning of............ 61

Tariff on mica, changes in................... 19-20

Tarkington mine, N. C., description of....... 173

Taylor, Louis, prospect, Ala., description of.. 44 

Temple, Ga., deposit north of................ 71

Tennessee Bald, N. C., mine southeast of.... 266

Terry prospect, S. C., description of.......... 285

Texas, deposits in......................... 302-306

Texas Creek region, Colo., prospect in........ 56

Texas Mica Co.'s mine. Tex., description of. 303-306 

"Thin splittings," process of making........ 22

Thomas, John H., prospect, Ala., description

of................................ 30

Thomas mine, Colo., description of.......... 58-59

Thomason mine, Ga., description of......... 82

Thomaston, Ga., deposits near............... 86

Thompson, W. A.., mines, N. C., description

Of.............................. 221-222

Thompson, W. H., mine, N. C., description of.. 189 

Thorn Mountain mines, N. C., description

Of.............................. 241-243

Three Forks, N. C., mine near............... 196

111375 23 23

ToUey, F. M., mine, N. C., description of.... 257

Tourmaline, exposed at Philip Geering's

mica prospect, plate showing.... 300

Trimming shop of Ridgeway Mica Co., plate

showing......................... 301

of Walnut Knob mica mine, plate showing........................:..... 170

Triplctt, Joel, mine, N. C., description of.... 271

Tripp No. 1 and No. 2 mines, k. H., description of......................... 110-111

TuggMountain, N. H., mines on.......... 134-137

Tulip, N. C., mine near.................... 263-265

Tung ash, mining and preparation of........ 50

nature and use of........................ 25-26

Tunnel mine, Ga., description of............. 85

Turkey's Nest mine, N. C., description of.... 241

Turner mine, Va., description of............ 327

Turner prospect, Ga., description of......... 83

Tustin kaolin and mica mines, N. C., description of................ ........ 200-201

U.

Union Mills, N. C., prospects near........... 263

Union mine, N. H., description of........... 128

United Mica Co.'s mine, N. H., description

of.............................. 147-148

Uranium, occurrence of.. 60-61,251,256,260,261,279 

United States Mica Co., mines of, near Micanite, Colo...................... 51-55

Uses of mica................................. 23-26

Utah, prospect in............................ 306

Valencia mine, N. H....................... 124-125

Van Horn, Tex., mine southwest of........ 303^306

Vance mine, N. C., description of.......... 179-180

Vance, Matilda, mine, N. C., description of... 183 

Varieties of mica............................. 11

Vermont, deposit in......................... 307

Virginia, mines and prospects in........... 307-330

Virginia Mica Producing and Manufacturing

Co.'s mines, description of..... 313-314

W. 

Wake Forest, N. C., prospect southwest of.... 268

Walker, J. W., prospects, Ga., description of. 83 

Walker, Wash, mine, Ga., description of..... 83

Walnut Knob mine, N. C., description of.. 176-177 

mica-trimming shop of, plate showing.... 170

Ward Gap mine, Ga., description of......... 81

Ward mine, Ga., description- of.............. 80

Ware, Nelson, mine, Ala., description of..... 43

Warner, B. H., mine, Md., description of... 104-105 

Washburn, Maynard, mine, N. C., description

of................................ 192

Washington, depositsin...................... 330

Watson, D. L., mine, N. C., description of.. 215-216 

Watts, A. S., cited........................... 22-23

Wayah Bald mine, N. C., description of.... 239-240

Wayehutta kaolin and mica mine, N. C.,

description of.................. 207-208

Waynesville, N. C., mines south of........ 194,195

Webster, N. C., mines and prospects near.... 201-

203,206 

"Wedge" mica, aggregate of, with A mica,

plates showing.................,«. 18 

origin of and use of name................ 16-17
342 INDEX.

Welbom prospect, S. C., description of...... 286

Welch, Arthur, mine, N. C., description of. 269-270 

Welch mine, N. C., description of.......... 233-234

Wells, I. T., prospect, N. C., description of.. 195-196 

Wentworth, N. H., mines in and near..... 122-124

Wesner Bald, N. C., mine south of........... 197

West Brothers mine, N. C., description of.... 233

West Rumney, N. H., mines near......... 118-122

Westall mine, N. C., description of........... 257

Westinghouse Co., mines of, in South Dakota........................... 292-299

Westphalen, B. B., cited.................... 247

Wests Mill, N. C., mine near................. 233

Wharton mine, S. C., description of........ 284-285

Wheat mine, N. H., description of........... 121

Wheeler, J. B., prospect, Ga., description of.. 73-74 

Whicher & Pillsbury prospect, N. H., description of.................... 122-123

White, George, prospect, description of...... 201

White, Jehial, mine, N. H., description of.. 115-116 

White mine, N. C., description of............ 276

White Spar mine, S. Dak., description of.. 295-297

engine and shaft house of, plate showing. 300

Whiteside Mountain, N. C., mine near....... 216

Wiarda quarry, Conn., description of........ 70

Wild Meadows mine, N. H., description of. 148-149 

Wild Rose claim, Colo., description of....... 56

Willes's, G. D., feldspar quarry, .Maine,

description of................... 101

Willetts, N. C., mine south of.............. 207-208

Williams Mine, Ga., description of........... 79-80

78

Williamson, J. B., prospects, Ga., description 

of................................

Willimon mine, S. C., description of.....

view toward workings of, plate showing.. 260 

Willis, Bill, mine, N. C., description of.... 256-257

Willis mine, Va., description of............ 328-329

Wilson, I. K., prospect, N. C., description of. 221 

Winding Stair mine, N. C., description of.... 243

Winecofl mine, N. C., description of....... 236-237

Wiseman, W. W., mine, N. C., description

of.............................. 258-260

view across deep open stope of, plate

showing.......................... 260

Wolf Mountain, N. C., mines on............ 220

Wolf Pen Gap Trail prospect, N. C., description of........................... 209

Wood, Jim, mine, N. C., description of.... 217-218

Woodland, Ga., prospects near.............. 86

Woods, Hamp, prospect, N. C., description

Of................................ 210

Wyatt mine, N. C., description of........... 189

Wyoming, deposits and prospects in....... 330-333

Wyoming lode, S. Dak., description of....... 302

Y.

YadMnville, N. C., mine east of........... 271-273

Yarborough, Smith & Neighbor prospect,

Ala., description of.............. 46

York prospect, Maine, description of......... 98

Young, A. W., mine, N. C., description of... 244 

Young mine, N. C., description of......... 275-276

o