Gem Stones of the 

United States

GEOLOGICAL SURVEY BULLETIN 1042-G

A CONTRIBUTION TO ECONOMIC GEOLOGY

GEM STONES OF THE UNITED STATES

By Dorothy M. Schlegel

ABSTRACT

Many semiprecious, but few precious, gem stones have been found in the 

United States. Beauty, durability, and rarity are the most important qualities 

of a precious gem. Gem stones are distinguished by their, physical properties: 

color, crystal form, cleavage, parting, hardness, specific gravity, luster, 

index of refraction, transparency, and dispersion. Gems are named for their 

color, type locality, outstanding physical property, or persons. The most 

popular gem cuts are the cabochon, rose, brilliant, step, and mixed. The 

carat, one-fifth of a gram or 200 milligrams, is the unit of weight measurement. The color of four popular gems may be changed by heat treatment or 

dyeing. Only the ruby, sapphire, spinel, emerald, rutile, and quartz of gem 

quality have been synthesized. The best quality of assembled stones are the 

doublet and triplet. Most gem stones are found in alluvial gravels and igneous 

rocks, especially granite and pegmatite deposits.

INTRODUCTION

Gem stones generally are divided into two categories: precious 

and semiprecious. A precious gem stone has beauty, durability, 

and rarity, whereas a semiprecious gem stone has only one or 

two of these qualities. The diamond, emerald, ruby, and sapphire 

are considered precious gems. Some opal is precious, but most 

varieties are semiprecious.

The beauty of a gem stone is determined by personal taste. In 

ancient times man preferred brightly colored, translucent or 

opaque stones. Today he prefers .evenly tinted, transparent 

stones. The desired hues are blue, rose, green, and true canary 

yellow in the diamond; pigeon-blood red in the ruby; cornflower 

blue in the sapphire; and grass green in the emerald. Most 

diamonds, however, are colorless.

The durability of a gem stone depends upon its hardness and 

lack of ready cleavage. A gem must be sufficiently hard to resist 

abrasion by objects normally found in everyday life and by dust. 

It should also resist the chemicals withwhichitcom.es in contact. 

Cleavability is the tendency of certain gems to split in one direction more readily than in another.

Rarity is one of the most important factors in establishing the 

price of a gem stone. Such gems as the diamond and ruby are 

rare, in addition to being beautiful and durable, and therefore are 

very expensive. Although the deep redpyrope garnet closely resembles the ruby in color, there is no comparison in expense and 

popularity. . .

203
CONTRIBUTIONS TO ECONOMIC GEOLOGY

.The purpose of this report is to give the amateur gemmologist 

some of the important information available on the gem stones of 

the United States. Although the finest precious gems occur in 

foreign countries, a wide variety of semiprecious stones, and a 

few precious gems, have been found in the United States. About 

50 major gems and the geology of their occurrence are described 

in this report. William F. Foshag, U. S. National Museum, has 

kindly reviewed the manuscript and made many valuable suggestions. Dana's "A textbook of mineralogy" is the source of the 

chemical formulas.

PHYSICAL PROPERTIES

Physical properties are important aids in identifying gems. 

They are: color, crystal form, cleavage, parting, hardness, specific gravity, luster, index of refraction, transparency, and dispersion.

Color is the first property noticed in a gem stone. Minerals of 

constant chemical composition usually have definite, characteristic colors. Many minerals, however, have varying chemical 

compositions and therefore a wide range of colors. Impurities, 

such as iron, chromium, and copper, also tint the minerals. Care 

should be taken in using color as a means of gem identification because it is not a constant property in most minerals.

Most gem stones have certain crystal systems that form under 

favorable conditions of temperature and pressure. If the conditions of formation are unfavorable, -an amorphous mass having no 

particular atomic arrangement results. The six crystal systems 

in which gem stones may form are: isometric, hexagonal, tetragonal, orthorhombic, monoclinic, and triclinic.

Cleavage is.the tendency of certain gem stones, when struck in 

the proper place, to split in one direction more readily than in 

another and yield plane surfaces. These plane or cleavage, surfaces are parallel to some of the crystal faces of some gem stones. 

For example, diamonds maybe cleaved in four directions parallel 

to the faces of an octahedron. Ready cleavage, however, can be 

a handicap; topaz and kunzite, for example, are difficult to cut 

into faceted gems because of this factor.

Certain minerals form planes of structural weakness if exposed 

to Stress or pressure. These planes are known as parting. 

Twinned crystals and certain minerals that have been subjected 

to the critical pressure are usually affected in this manner.

Hardness is the resistance a gem stone offers to abrasion or 

scratching/ The hardness of a gem stone may be determined by 

scratching it with another mineral or with a knife blade. This may 

mutilate tllQ StOne. A Series of 10 minerals, known as Moh's 

Scale of hardness, has been established to show relative 

of hardness.
GEM STONES OF THE UNITED STATES 205

MOH'S SCALE OP HARDNESS

1. Talc 6. Orthoclase

2. Gypsum 7. Quartz

3. Calcite . 8. Topaz

4. Fluorite 9. Corundum

5. Apatite 10. Diamond

The numbers preceding each mineral indicate only increasing 

degrees of hardness, not actual values. For example, the diamond, rated as 10, is many times harder than corundum, rated 

as 9. Corundum is placed next to diamond only because it is the 

mineral nearest the diamond in hardness. Because much dust is 

composed of silica (quartz, 7 on Moh's scale) particles, a gem 

stone should be harder than quartz.

Some minerals are harder in one direction than another. When 

testing a gem for hardness, the gem stone should be rubbed against 

the test stone, not vice versa. Cut stones can be badly damaged 

by permitting several of different hardness to be carried in contact with one another.

The specific gravity of a mineral is the ratio between its weight 

and the weight of an equal volume of water at 4° C. It is a constantproperty of all minerals of fixed compositior The amateur 

gemmologlst need not determine the specific gravity accurately, 

but he should learn to compare the relative weights of stones.

Luster, the general appearance of a mineral in reflected light, 

is of two types: metallic and nonmetallic. Most gem stones are 

nonmetallic. Terms used to.describe nonmetallic lusters are: 

vitreous or glassy, resinous, pearly, greasy or waxy, silky, and 

adamantine or brilliant. Luster is influenced by the index of refraction, transparency, and dispersion of a gem stone.

When light rays pass from air into a denser medium, they are 

bent or refracted. The velocity of light is diminished in the 

denser medium. The ratio between the velocity of light in air and 

that in the gem stone is known as the index of refraction. If a 

gem is transparent, the maximum amount of light is refracted. 

In translucent or opaque stones only part of the light is refracted. 

Dispersion is the ability of a mineral to separate white light into 

colored rays. Because the degree of refraction for different 

colors of light differs with each mineral, certain minerals have 

a higher dispersion than others. The diamond owes its fiery brilliance to a high index of refraction and high dispersion.

TECHNOLOGY

GEM NAMES

In ancient times gem names were based principally on color. 

The term "ruby" was applied to all red stones: spinel, ruby, 

garnet, and rose tourmaline; the term "sapphire," to lapis lazuli 

and other blue stones; the term "topaz," to all yellow stones; and
206 CONTRIBUTIONS TO ECONOMIC GEOLOGY

the term "emerald, " to chrysocolla and all other green stones 

(Smith, 1949, p. 175). Corundum was referred to as "oriental" 

because the first specimens were brought to Europe from the 

Orient. Modern nomenclature for gems is based on the color, 

type locality, or an outstanding physical property of the gem. 

Several gems, such as uvarovite and kunsite, have been named 

for persons.

GEM CUTS

Most gem stones used in jewelry must be cut to reveal their full 

brilliance. In ancient times a gem stone was treasured for its 

surface coloration rather than its brilliance; therefore, gems were 

merely polished and left in their natural state. 

/ The oldest, type of gem cut in use today is the cabochori or rounded 

ut introduced by the Romans (Smith^l949, p. 141). The cabochon 

Was used for colored stones, such as the emerald, ruby, sapphire, 

and garnet, but is now used only for-sta-rstones, cat's-eyes, opals, 

and generally opaque and imperfect stones.

The art of faceting a gem stone originated in India in the 15th 

century (Smith, 1949, p. 142). The first faceted gems were diamonds that had been haphazardly cut to disguise any flaws or carbon spots. In the early 17th century the rose cut, a symmetrical 

form consisting of a flat base and a faceted top terminating in a 

low point, was invented and used for cutting large diamonds. 

This form was varied in the Dutch rose, Antwerp rose, and rose 

recouped. The brilliant cut, consisting of 56 facets plus the table 

andculet, was invented at the end of the 17th century. It revealed 

the fiery brilliance of a diamond for the first time and is still the 

standard cut for the diamond. Modifications of the brilliant form 

are the jubilee cut (88 facets), English brilliant (30 facets), the 

marquise, and the drop form.

The other faceted forms are the step cut, used for emeralds 

and exceptionally good diamonds, and the mixed cut, a combination step cut and brilliant cut. The purpose of a step cut is to

display the color of a gem rather than its brilliance. The depth

of this cut varies with the depth of color in the stone. A darkcolored stone is lightened by a shallow cut, and a light-colored 

stone is darkened by a deep cut. The mixed cut is used to heighten 

the beauty of irregularly colored stones, such as tourmaline.

UNIT OF WEIGHT

The carat, meaning one-fifth of a gram or 200 milligrams, is 

used as the unit for weighing gem stones. The cost of a gem stone 

is the result of the price per carat multiplied by the weight. The 

price per carat of a precious stone increases with size.

METHODS OF CHANGING COLOR IN GEM STONES

The color of many gem stones may be partly altered or driven 

off completely by the use of heat. The atoms of the coloring agent
GEM STONES OF THE UNITED STATES 207

are thereby permanently rearranged. Heat is used to produce 

some of the tints rarely found in nature. Yellow topaz from Brazil 

can be heated carefully and cooled to produce a permanent pink, 

resembling the rare, natural pink topaz. In a similar manner a 

colored zircon may be heat-treated and thereby become colorless 

or changed to a different color. Other stones that react to heat 

are: violet quartz (amethyst) changing to orange brown, smoky 

quartz to yellow, pale-green beryl to blue, violet corundum to 

rose pink, and yellow corundum to colorless.

Dyeing is another means of changing the natural color of a gem 

stone. This method is most often used in porous stones, such as 

the agate. The unattractive gray and pale shades may be changed 

chemically to bright red, green, and blue shades. The common 

dyeing procedure is to soak the agate in the desired chemical 

(nitric acid for red shades, nitrates and chromium salts for green 

shades, and certain cyanates and sulfates for blue shades). The 

Romans dyed agate by soaking it in honey, removing it from the 

liquid, and heating it; this produced black bands. Today the same 

effect is achieved by first soaking the agate in a sugar solution, 

and then in sulfuric acid to char the sugar.

SYNTHETIC STONES

Ruby, spinel, emerald, sapphire, star sapphire, star ruby, 

rutile, and quartz are gem stones that have been successfully synthesized. A reddish-green stone known as synthetic alexandrite 

is actually synthetic corundum. A stone of simple chemical composition generally is more easily synthesized than one of complex 

composition. Although the diamond has the simplest composition 

of any gem stone (C, or carbon), synthetic gem diamonds have 

never been perfected; on February 15, 1955, the General Electric 

Co. synthesized some very small industrial diamonds. The ruby 

has a simple composition of A12O3, or 2 molecules of aluminum 

and 3 molecules of oxygen. Synthetic gem rubies are made by growing a boule (or pear-shaped mass) composed of A1203. Although the 

boule does not resemble a natural ruby crystal, it possesses most of 

the physical properties of the natural stone. Sometimes the following distinctions can be made between synthetic and natural 

stones: natural stones contain cavities that are never spherical; 

synthetic stones are never perfectly uniform in structure; and the 

growth lines of a stone cut from a boule appear as curved striae 

under the microscope; natural stones sometimes have straight 

growth lines.

IMITATION AND ASSEMBLED STONES

Gems made of glass are known as imitation stones. Unlike synthetic gems, imitation stones resemble true-gems only in color. 

Cheap imitations are made from bottle glass or lead glass; more 

exact imitations are made from special glass or paste. "Reconstructed gems" are prepared from inferior gem material. Two 

of the more exact "assembled stones" are the doublet and triplet.

41Z673 O - 57 - Z
20° CONTRIBUTIONS TO ECONOMIC GEOLOGY

The doublet consists of two different substances cemented together. 

The top of the stone may be quartz and the bottom, glass; or the 

top may be genuine sapphire, deficient in color, and the bottom, 

paste of bright blue to compensate for the pale color of the sapphire. The triplet is an assembled stone in which the top and 

bottom are rock crystal cemented with colored canada balsam. 

The doublet and triplet are easily detected by immersing them in 

an oil and thereby seeing the separate layers or by dissolving the 

canada balsam in boiling water, causing the pieces to separate, 

but ruining .the stone.

GEOLOGIC -OCCURRENCE

Gem stones are found principally in igneous rocks and alluvial 

gravels, but also in sedimentary and metamorphic rocks. The 

finest gems are cut from large, perfect stones with even color 

distribution. Igneous rocks, such as granite, are formed deep in 

the earth's interior and some contain rifts and cavities where gem 

stones have formed under the proper conditions. In some places, 

molten masses of igneous rocks are forced into cracks of other 

rocks, forming veins or dikes. Some pegmatite dikes contain a 

variety of gem stones, such as tourmaline, beryl (emerald, aquamarine), spodumene (kunzite, hiddenite), zircon, and gem varieties of feldspar, topaz, and quartz. Gem stones maybe weathered 

out from their matrix, washed away in streams, and eventually 

deposited as alluvial gravels. Opal and agate are formed from 

aqueous solutions. Diamonds are found inkimberlite, a rare volcanic rock.

PRECIOUS GEMS

DIAMOND 

Physical properties: c

Color: Usually colorless, pale yellow or pale brown; also gray

and black, rarely green, blue, or pink. 

Crystal form: Isometric (cubic, .octahedron). 

Cleavage: Perfect, parallel to octahedron faces. 

Hardness: 10.

Specific gravity: 3:516-3.525. 

Luster: Adamantine, also greasy.

The diamond has many unusual qualities: extreme hardness, 

high index of. refraction, strong color dispersion, and fiery brilliance. Composed of pure carbon, it has the simplest composition 

of all gems.

In the United States, more than 50,000 diamonds have been 

found in kimberlite near Murfreesboro, Ark. Kimberlite is a 

dark, greenish-black igneous rock of the peridotite family. It is 

composed Of partly altered olivine phenocrysts in a dense ground 

mass. The kimberlite in Arkansas occurs in four small areas 

the largest of which appears to be a volcanic neck. The kimberlite includes breccia and tuff and weathers to a soft, friable, 

yellowish or greenish mass and black soil in which most of the 

diamonds have been found.
GEM STONES OF THE UNITED STATES 209

Elsewhere in the United States, diamonds have been reported in 

four regions: the Pacific Coast, Great Lakes, central Kentuckyeastern Tennessee, and the Atlantic Coast-Piedmont. The Pacific 

Coast diamonds are found in sand and gravel of riverbeds and 

streambeds, principally derived from rocks of the Sierra Nevada. 

Specific localities in California where diamonds have been found 

are: Smith River, Del Norte County; Trinity River, Trinity County; 

Spanish Creek and Gopher Hill, Plumas County; Placerville and 

Webber Hill, El Dorado County; Cherokee Flats, Yankee Hill,and 

Oroville, Butte County; French Corral, Nevada County; Indian 

Gulch and Volcano, Amador County; and Alpine Creek, Tulare 

County. Other western localities are: Diamond Basin, Ada 

County, Idaho; Curry County, Oreg.; and Nelson Hill, near Glacier 

County, Mont. The Great Lakes diamond region is essentially 

the terminal moraine of the last ice sheet. Diamonds have been 

found in Wisconsin at Plum Creek, Pierce County; Oregon, Dane 

County; Kohlsville, Washington County; Saukville, Ozaukee County; 

Eagle, Waukesha County; and Burlington, Racine County. Other 

localities in the Great Lakes region are Dowagiac, Cass County, 

Mich.; Lick Creek, Brown County, Ind.; and Milford, Clermont 

County, Ohio. Diamonds have been found in Kentucky at Cabin 

Fork Creek, Russell County, and in Tennessee at Clinch River, 

near Union Crossroads, Roane County; Luttrell, Flat Creek, Union 

County; and Koko Creek, Tellico River, Monroe County. In the 

Atlantic Coast-Piedmont region many diamonds have been found 

in sand and gravel deposits derived from nearby crystalline rocks. 

Specific localities in North Carolina are Brindletown Creek Ford, 

Burke County; the J. B. Twitty gold placer mine, Rutherford County; 

Cottage Home, Lincoln County; Todds Branch, Mecklenburg County; 

Muddy Creek, Dysortville, and near Dysortville, McDowell County; 

Kings Mountain, Cleveland County; and Portis gold mine, Franklin 

County. In South Carolina diamonds have been found in Spartanburg 

County; in Virginia, at Manchester, Chesterfield County; in Georgia, at Gainesville in Hall County, Horshawmine in Acooche Valley, 

and Morrow Station in Clayton County; in Alabama, in Lee and 

Shelby Counties; and in West Virginia, at Peterstown. Diamonds 

have also been found in Huntsville, Tex.

BERYL (EMERALD) . Be3Al2 (SiO3)6 

Physical properties:

Color: Grass green.

Crystal form: Hexagonal.

Cleavage: Indistinct, parallel to basal face.

Hardness: 7.5.

Specific gravity: 2. 63-2.80.

Luster: Vitreous.

Emerald is the only precious variety of beryl. Its grass-green 

color has been attributed to the presence of chromic oxide. 

Emerald crystallizes in a six-sided prism terminated by a basal 

face at right angles to the prism edge. It is faintly dichroic,
210 CONTRIBUTIONS TO ECONOMIC GEOLOGY

showing a deeper color in one direction than another. The hardness of emerald is a little less than that of the other varieties of 

beryl. All varieties of beryl are brittle and therefore easily fractured. Most emeralds are badly flawed and no large, unfLawed 

stone is known. Emeralds are usually step cut, but some are 

brilliant cut. A flawless stone of good quality and larger than 

6 carats would have a much higher value than a diamond of equal 

size.

Emeralds occur in granitic rocks; such as silicic pegmatite, 

in high-temperature calcite veins, in crystalline schist, and in 

altered marble.

In North Carolina, emeralds have been found at the Emeraldhiddenite mine, Alexander County; Turner mine, Cleveland County; 

and the Emerald matrix mine, Crabtree Mountain, Mitchell County. 

None of these mines is active. At the Emerald-hiddenite mine 

emerald crystals of gem quality, associated with rutile crystals, 

black tourmaline, feldspar, quartz, hiddenite (blue-green gem 

variety of spodumene), and aquamarine, occurred in schleiren in 

gneiss. Only a few pegmatites are gem bearing. At the Turner 

mine, about a dozen emerald crystals of good grass-green color, 

associated with colorless and smoky quartz crystals and black 

tourmaline (Sterrett, 1909, p. 31), were found loose in the soil.1 

The country rocks are schist and gneiss intruded by masses of 

granite. Only one pegmatite dike yielded a few small emerald 

crystals of pale green color. The emeralds occurred with quartz, 

feldspar, black tourmaline, and green beryl, in a red, clayey 

cavity. Most of the emeralds found at these two mines were flawed 

by scratches and silky internal markings. At the Emerald matrix mine the stones were flawed and pale. Occurrences of emerald also have been reported near the Bowen River, Cherokee 

County, S. C.

CORUNDUM

A1203

Ruby and sapphire 

Physical properties:

Varieties: Sapphire (blue and all colors except red), ruby (red),

star sapphire, star ruby. 

Crystal form: Hexagonal. 

Parting: Parallel to basal plane and unit rhombohedron.

Hardness; 9,

Specific gravity: 3. 95-4. 10. 

Luster: Adamantine to vitreous.

Ruby and sapphire are the important gem varieties of corundum. 

The color of the ruby ranges from rose to dark-purplish red. The 

dark red or "pigeon-blood" red is the most desirable. The sapphire ranges in color from blue to pink, yellow, and colorless with 

some green and violet varieties. The finest stones are "cornflower 

blue. " Good color is important because corundum gems have low
GEM STONES OF THE UNITED STATES 211

dispersion and, therefore, lack fire. Both stones are dichroic. 

The color of a ruby is thought to be caused by chromic oxide, and 

that of a sapphire by titanium oxide (Smith, 1949, p. 273). Radiation deepens color in these stones or creates color if they were 

previously colorless. When heated, a ruby turns green and retains 

this shade until almost cool at which time it regains its original 

red color. A star ruby or sapphire contains fibrous inclusions 

arranged in bundles 60° apart. This starlike structure is best displayed when the stone is properly oriented and cut in deep cabochon.

The original sources of ruby and sapphire are metamorphic 

rocks, such as gneiss, schist, and marble, and igneous rocks, 

such as granite,'nepheline-syenite, and peridotite. The gems are 

found in the parent rock or in placer deposits derived from these 

rocks. Commonly associated minerals are spinel, tourmaline, 

kyanite, magnetite, chlorite, and nepheline.

The only notable locality where rubies have been mined in the 

United States is Cowee Valley, Macon County, N. C. Here, the 

rubies probably were formed in a matrix of hornblende gneiss and 

pegmatite lenses in hornblende gneiss. Both the gneiss and pegmatite are badly weathered at the surface. In the decomposed 

pegmatite, pink to lilac-colored corundum is abundant, but little 

red corundum of gem quality has been found. Most of the gem 

material was obtained from nearby stream gravels. Associated 

minerals were all shades of corundum, ilmenite, rutile, kyanite, 

red and pink rhodolite garnet, and zircon. Gem rubies also have 

been found in the Calumet mine, Salida, Colo.; Marion Claim, 

Fremont County, Wyo.; and in Yogo Creek, Judith Basin County, 

Mont.

Sapphires have been mined in many localities in Montana; the 

largest mine is near Yogo Gulch, Judith Basin County. The sapphires occur in a nearly vertical igneous dike that intrudes gently 

dipping limestone. The dike rock is easily weathered to soft, 

yellow or gray clay at the surface and greenish-gray friable rock 

and blue clay at depth (Clabaugh, 1952, p. 11). The principal 

minerals in the dike rock are biotite mica and pyroxene (diopside 

variety) containing minute inclusions ofcalcite, quartz, pyroxene, 

and pyrite. Limestone fragments are abundant. The dike is irregular in shape and contains alternate zones of rich and barren 

rock (Sterrett, 1907, p. 30). The rock is barren where the dike 

is narrow (Clabaugh, 1952, p. 17). The" color of the stones is 

uniform and ranges from light blue to cornflower blue. Other 

Montana sapphire deposits are the Missouri River deposits, northeast of Helena; the Rock Creek deposit, southwest of Philipsburg, 

Granite County; Dry Cottonwood Creek deposit, northwest ofButte, 

Deer Lodge County. Other Montana sapphire occurrences are 

Quartz Gulch, Granite County; Pole Creek, Madison County; 

Browns Gulch, Silver Bow County; and in Chouteau County 

(Clabaugh, 1952, p. 54-55).

Sapphire occurrences in other States have been reported at 

Barstow, San Bernardino County, Calif.; at the Calumet iron mine, 

Chaffee County, Colo.; several localities in Fremont County, Colo.;
212 CONTRIBUTIONS TO ECONOMIC GEOLOGY

in Adams and Washington Counties, Idaho; Morgan County, Ind.; 

at the Sapphire and White Water mine, Jackson County, N. C.; 

and at Corundum Hill mine, Macon County, N. C.

SEMIPRECIOUS GEMS

BERYL 

Aquamarine, heliodor, morganite

Be3Ala (SiO3)6 

Physical properties:

Varieties: Aquamarine (bluish green), heliodor (golden yellow),

morganite (rose pink). 

Crystal form: Hexagonal. 

Cleavage: Indistinct, parallel to basal face. 

Hardness: 7.5-8.0. 

Specific gravity: 2. 63-2.80. 

Luster: Vitreous.

The semiprecious varieties of beryl are aquamarine, heliodor, 

and morganite. Aquamarine ranges in color from yellowish green 

to bluish green, heliodor is golden yellow, and morganite ranges 

from rose pink to rose red. Beryl also occurs in yellow, blue, 

and colorless crystals. The shades of aquamarine are probably 

due to the presence of ferric oxide; whereas those of morganite 

may be due to the presence of lithia; and the color of heliodor, to 

the presence of uranium oxide (Smith, 1949, p. 286). These varieties occur in larger quantities, bigger crystals, and have more 

uniform transparency than the emerald. Their beauty is best displayed in a step or mixed cut. The physical properties of beryl 

are discussed on page 209.

These varieties of beryl occur in granitic rocks, principally in 

pegmatite deposits. Aquamarine has been mined in Maine, Connecticut, California, New Hampshire, Colorado, Montana, Georgia, 

and North Carolina. Morganite and heliodor are rare in the United 

States. Salmon-pink beryl crystals of good quality, but few of 

true rose-red color, have been found in the Pala and Mesa Grande 

districts, San Diego County, Calif. Additional aquamarine localities are listed below:

California: ' San Diego County, Ramona 

Colorado: Chaffee County, Mount Antero region

Fremont County, Parkdale, Royal 

Gorge. 

Connecticut: Litchfield County

Middlesex County, Portland, Haddam

Georgia: Rabun County, Clayton, Highlands 

Idaho: Boise County, Centerville

Nez Perce County, Lewiston 

Maine: Androscoggin County, Mount .Apatite
GEM STONES OF THE UNITED STATES 213

Maine Cont.

Maryland: 

Massachusetts:

New Hampshire: 

North Carolina:

Pennsylvania:

South Carolina: 

South Dakota: 

Utah:

Oxford County, Albany, Buckfield,

Grafton, Lovell, Norway, Paris,

and Stoneham. 

Sagadahoc County, Topsham 

Baltimore County, Arundel gneiss

quarry.

Hampshire County, Goshen 

Worcester County, Fitchburg, Royal -

ston.

Grafton County, Grafton 

Alexander County, Barrett Mountain 

Buncombe County, Asheville 

Burke County, South Mountain 

Caldwell County 

Gaston County 

Jackson County, Grimshawe mine,

Montvale, R. E. Brown Prospect. 

Macon County, Littlefield mine, Tessentee Creek.

Madison County, Knapp's, Reed Creek 

Mitchell County, Bakersville 

Yancey County, Burnsville, Ray Mica

mine.

Delaware County, Avondale 

Montgomery County, Philadelphia are'a. '

Anderson County, Anderson 

Custer County, Black Hills 

Tooele County, Ibapah Mountain

Golden beryl has been found at the following localities:

California:

Connecticut:

Maine:

Maryland:

New Hampshire:

New York: 

North Carolina:

San Diego County, Pala district 

Litchfield County, Litchfield 

Androscoggin County, Auburn, Mount 

Apatite, and Poland. 

Montgomery County, Burnt Mills Hills 

Grafton County, Grafton 

Merrimack County, Danbury 

Strafford County, Center Strafford 

Sullivan County, Ac worth, Beryl Mountain. 

Westchester County, Bedford Village,

North Castle. 

Burke County, South Mountain

Occurrences of morganite have been reported at Simpson Springs, 

The Dugway Range, Utah, and at Hemet, Calif. It also has been 

recovered from pegmatite deposits in Maine.
214

Physical properties:

Varieties: Alexandrite (bluish green, deep olive green), cat's- "

eye or cymophane (chatoyant). 

Crystal form: Ortho rhombic. 

Cleavage: One, parallel to faces. 

Hardness: 8. 5. 

Specific gravity: 3. 50-3. 84. 

Luster: Vitreous.

Chrysoberyl ranges in color from shades of yellow and brown 

to bluish green and deep olive green. Alexandrite, the greenish 

 variety, has strong dichroism in columbine red, orange yellow, 

and emerald green. Cat's -eye or cymophane is a cloudy variety 

that is opalescent when properly oriented and cut en cabochon. 

Shades of yellow are caused by the presence of iron, and shades 

of green are probably caused by chromium. Chrysoberyl occurs 

in twinned, tabular crystals that lack brilliance. It is a hard gem 

stone, ranking 8. 5 on Moh's scale. Cat's -eye is cabochon-cut, 

whereas alexandrite is brilliant- or step-cut. Chrysoberyl has 

not been synthesized. The so-called synthetic alexandrite is 

either synthetic corundum or synthetic spinel.

Chrysoberyl is a rare mineral that occurs in granitic rocks, 

silicic pegmatites, and mica schist. Most gem varieties, however, have been found in alluvial deposits derived therefrom. 

Very few occurrences of gem Chrysoberyl have been reported in 

the United States. Localities are at Drew^Hill, Golden, Jefferson 

County, Colo. ; Boulder County, Colo. ; Haddam, Conn. ; Ragged 

Jack Mountain, Conn. ; Oxford County, Maine; and Greenfield, 

N. Y. The largest crystals of Chrysoberyl in the United States 

were obtained from a pegmatite dike at Drew Hill, Golden, Colo. 

(Pearl, 1951, p. 77). The olive -green Chrysoberyl was associated 

with quartz, muscovite, apatite, beryl, pyrite, and andradite.

FELDSPAR GROUP

Amazonite: KAlSi308 (microcline).

Oligoclase: 90-70 percent l,NaAlSi308]+ 10-30 percent CaAL,Si2Oe.

Labradorite: 50-30 percent NaAlSi30& -i- 50-70 percent CaAJ2Si2Oa

(plagioclase feldspar).

Moonstone: KAlSi308 and NaAlSi308 (albite and orthoclase). 

Sunstone: 90-70 percent [KAIS^OJ -I- 10-30 percent

(anorthite) .

Physical properties:

Species: Amazonite (green) jlabradorite (white, gray, brown with 

play of colors); moonstone (whitish); oligoclase (clear); sunstone 

(whitish with reddish and yellowish rays).

Crystal form: Monoclinic (orthoclase); triclinic (albite, labradorite, microcline, and oligoclase).
01 R 

GEM STONES OF THE UNITED STATES ^ °

Physical properties Continued

Cleavage: Excellent in two directions at 90°.

h

% Hardness: 6.0-6.5. 

Specific gravity: 2. 54-2.75. 

Luster: Vitreous, sometimes pearly.

Amazonite, labradorite, moonstone, oligoclase, and sunstone 

belong to the mineral group known as the feldspar family. Amazonite is the green gem variety of microcline; labradorite is a 

plagioclase feldspar showing a play of colors, predominantly blue 

and green; moonstone is a white gem variety of albite and orthoclase; gem oligoclase occurs as clear glassy crystals; and sunstone is white oligoclase, orthoclase, microcline, albite, or 

labradorite with reddish and yellowish reflections. Although these 

gem stones are somewhat similar in chemical composition, they 

differ in physical properties. The difference in their cleavage 

angles is 1°. Their color dispersion is very low. Moonstone, 

the most valuable gem stone of this group, is composed of thin 

layers of orthoclase and albite (the soda feldspar). This linear 

arrangement gives the whitish stone a blue cast: the thinner the 

layers, the bluer the stone. If the layers are thick, the stone has 

a white sheen. Sunstone is oligoclase, orthoclase, microcline, 

albite, or labradorite containing minute scales of hematite. This 

feature is caused by reflections from crystals of an iron mineral, 

hematite or goethite, scattered throughout the stone. Both moonstone and sunstone are cut en cabochon. Labradorite displays 

many colors: blue, green, yellow, fire red, and pearl gray. 

This effect is probably caused by the interference of light from 

the reflection of thin inclusions of several minerals. Amazonite, 

the most abundant feldspar gem in the United States, ranges in 

color from bluish green to greenish gray. It is opaque. Most 

jewelers cut amazonite into beads or carve figures from it.

Feldspar gems occur in igneous rocks, especially in pegmatite 

dikes. Very few specimens of moonstone have been found in the 

United States. The principal localities have been the Rutherford 

mine, Amelia Court House, Va.; Mount Beckwith, Colo.; and 

Rialto, Funeral Mountains, Calif. Sunstone has been found in 

Pennsylvania at Feasterville, Bucks County; Nottingham Township, 

Chester County; and Mineral Hill, Media, Delaware County. In 

North Carolina it has been found at Medlock Mountain, Bakersville; 

and in Virginia, at Hewlett, Hanover County, and Amelia Court 

House, Amelia County. Amazonite has been produced commercially in Colorado near Pikes Peak, El Paso County, and in the 

Crystal Peak region near Florissant, Teller County; and in Virginia near Amelia Court House, Amelia County. Other localities 

where amazonite has been found are in Colorado at Deertrail, 

Arapahoe County, near Sedalia, Douglas County, in Custer County, 

in the St. Peter's Dome area, El Paso County, and in the Tarryall 

Mountains, Park County; in Maine, at Mount Desert, Hancock 

County, and at Mount Mica, Paris, Oxford County; in Massachusetts, at Rockport, Essex County; in New Mexico, Rio Arriba

412673 O - 57 - 3
216 CONTRIBUTIONS TO ECONOMIC GEOLOGY

County; in North Carolina, at Burnsville, Yancey County; in 

Pennsylvania, at Media and Middletown, Delaware County; and in 

Texas, at Katemcy, Mason County.

The Pikes Peak region in Colorado is a famous collecting area 

for amazonite in the United States. The country rock is principally 

coarse biotite granite that has been cut by many pegmatites. Both 

the granite and pegmatites contain many cavities or pockets, some 

of which are lined with well-formed crystals of amazonite, smoky 

and clear quartz, some topaz, andphenacite (a colorless beryllium 

gem stone). The color of the Pikes Peak amazonite ranges from 

gray to bright green and may or may not be stained with iron minerals. Other associated minerals are microcline, albite, biotite, 

fluorite, columbite, goethite, hematite, limonite, and zircon.

The amazonite at the Rutherford mine, Amelia Court House, Va. , 

occurs in pegmatite dikes that cut biotite schist and gneiss. The 

dikes contain crystals of quartz, mica, and feldspar, large beryl 

crystals intergrown with feldspar, hyacinth-red spessartite garnet, and pale -purple fluorite. Labradorite occurs in the central 

Adirondack region, northern New York; the Byrd ranch, Alpine, 

Brewster County, Tex. ; and Clear Lake, Millard County, Utah.

GARNET FAMILY 

R3"R2" '(SiO4)3 R" = Ca, Mg, Fe ++ , or Mn ++ R" 1 ' = Al,

Fe +++, Cr, or Ti 

Physical properties:

Varieties: Grossularite (reddish orange); pyrope (fiery red);

almandite (columbine red); spessartite (orange to deep red);

andradite (demantoid, grass to emerald green; topazolite, wine

yellow); uvarovite (emerald green); rhodolite (purple or pale

red). 

Crystal form: Isometric.

Hardness: 6.5-7.5.

Specific gravity: 3.15-4.30.

Luster: Vitreous, resinous (andradite is subadamantine).

The term garnet applies to a group of six minerals which are 

closely related. This group crystallizes in the isometric system. 

Its basic chemical formula is the same, but the elements in each 

garnet differ widely. This group is an isomorphous series in 

which several chemically similar elements freely replace each 

other in solid solution.

Garnets are divided into three groups: the aluminum garnets, 

including grossularite, pyrope, almandite, and spessartite; the 

iron garnet, andradite; and the chromium garnet, uvarovite. The 

popular gem garnets are the fiery-red pyrope, crimson and columbine-red almandite, and the emerald-green andradite. Grossularite is not often used for gems because its color is not pleasing 

and its transparency is imperfect. Deep-red spessartite is very 

rare and, therefore, not often available for gem purposes. Green 

uvarovite is never used for gems because it does not occur in 

crystals large enough to cut.
91 7 

GEM STONES OF THE UNITED STATES ^ L

: cinnamon-stone, hyacmthoressonite:Ca3A!2( Si 04)3 . 

The color of grossularite ranges from pale olive -green yellowish orange to reddish brown. Cinnamon-stone is the golden-yellow grossularite, and hyacinth or essonite is the orange and 

reddish-brown variety. The hardness of grossularite is 7. 25, a 

little harder than quartz. Its specific gravity is 3. 53.

Pyrope:

The red color of pyrope in some stones resembles that of the 

ruby. Pyrope ranges from deep red to nearly black. Rhodolite 

is a rose -red and purple subvariety, having a composition of two 

parts pyrope and one part almandite. The hardness of pyrope is 

7. 5, and its specific gravity is 3. 51.

Almandite (carbuncle): Fe3Al2(Si04)3.

Almandite, which has a variable chemical formula, grades into 

pyrope. Its color is deep crimson and violet or columbine red. 

Almandite ranks 7. 5 on Moh's scale of hardness and is harder 

than the other garnets, with the exception of uvarovite. Its specific gravity is 4. 25. Good-quality almandite is more expensive 

than pyrope. The carbuncle is a crimson -red almandite cut en 

cabochon.

Spessartite: Mn3Al2(SiO4)3.

Spessartite is a beautiful aurora red or brownish red; it would 

be a very popular gem stone if it were not so rare. Its color may 

also be yellow or orange brown. The hardness of Spessartite is 

7. 25, and its specific gravity is 4. 18.

Andradite (demantoid, top azo li t e):

The iron garnet, andradite, is a common garnet, but its subvarieties, demantoid and topazolite, are gem materials. Common 

andradite ranges in color from wine, greenish yellow, brownish 

yellow, grayish, to dark green, and grayish black to black. 

Demantoid is emerald green and has a brilliant luster. It is the 

most valuable of all garnets. Topazolite is wine yellow and closely 

resembles some topaz in color. The specif ic gravity of andradite 

is 3.75, and its hardness is 6.5.

Uvarovite: Ca3Cr2(SiO4 )3 .

The chromium garnet, uvarovite, is emerald green and has a 

vitreous luster. Its hardness is 7. 5, and its specific gravity 

ranges from 3.41 to 3. 52.

Garnet is a common and widely distributed accessory mineral. 

It is found in metamorphic rocks, such as mica schist, hornblende 

gneiss, and marble; in pegmatite dikes; in basic igneous rocks, 

such as dunite and peridotite; and rocks, such as serpentine, derived from them.

Grossularite and essonite are found chiefly with vesuvianite, 

wollastonite, diopside, and scapolite in marble and dolomite. This 

species and its subvariety are usually found in the contact zone of
CONTRIBUTIONS TO ECONOMIC GEOLOGY

igneous intrusives with metamorphic rocks. Beautiful essonite has 

been found in Andover, Maine; at theLeiper quarry, Avondale, Pa.; 

in Bakersville, N. C 0 ; in Silver City, N. Mex.; at the Calumet 

iron mine, Turret, Colo.; and in Dos Cabezas Springs, San 

Diego County, Calif. Grossularite crystals of no gem value 

have been found in Gila Canyon, Ariz.; Tilly Foster mine, Brewster, N. Y.; and the Good Hope mine, Pala district, San Diego 

County, Calif.

Pyrope is characteristic of peridotite rocks and serpentines 

containing much magnesia and iron. The finest pyrope garnets 

have been found in gravels on the Navajo Indian Reservation in 

northwestern New Mexico and northeastern Arizona near Gypsum 

Valley (Sterrett, 1908, p. 25). Other localities are Deadwood 

Gulch, Boise County, Idaho; Elephant Gulch, Custer County, 

S. Dak.; Rattlesnake Creek, Tulare County, Calif.; Laurel Creek, 

Burke County, N. C. Rhodolite, the rose-red and purple subvariety, occurs in stream gravels in Mason Branch Valley, near 

Franklin, Jackson County, and Cowee Valley, Macon County, 

N. C. The gravels probably were derived from mica schist containing large amounts of biotite and bronzite (Sterrett, 1910, 

p. 27).

Almandite occurs in mica schist and other metamorphic rocks 

containing alumina and iron. In Avery, Burke, Caldwell, and 

Catawba Counties, N. C., it is incrusted with brown limonite. 

Deep-purple crystals have been found in placer gravels near 

Lewiston, Idaho. Other localities are Black Canon, Colorado 

River, Nev.; White Pine County, Nev.; Acworth, Grafton, and 

Hanover, N. H.; Ruby Mountain, Canon City, and South Park, 

Colo.; Chester and Delaware Counties, Pa.; and Gore Mountain, 

North-Creek, N. Y.

Spessartite occurs in some granitic rocks, quartzite, and schist. 

At Ruby Mountain, Chaffee County, Colo., it is found with topaz 

in rhyolite. Other localities are Fairmount Park, Philadelphia, 

Pa. j Haddam, Conn.; Amelia Court House, Va.; and in San Juan 

County, Utah.

Andradite is a common constituent of volcanic rocks; associated 

minerals are nephelite and leucite. It also is found in limestone 

contact zones. The subvarieties, demantoid and topazolite, also 

occur in volcanic rocks but are not common. A few localities 

where common andradite has been found are in Lehigh County, 

Pa.; Franconia, N. H.; and New Haven, Conn. Demantoid of

gem quality has not been found in the United States, but topazolite has been obtained from Mount Sneffels, Colo. and Magnet

Cove, Ark.

Uvarovite, the chromium garnet, OCCUrS With ChrOffilte 111 

Serpentine and also in granular limestone. Small amounts have 

been found at Wood's chromite mine near Texas, Lancaster 

COUIlty, Pa. j at Tilly Foster mine, Brewster, N. Y.; at Green

Valley, American River, Calif.; Jacksonville, Calif.; Clear 

Creek, Idria, San Benito County, Calif.; and in the Graham Mountain, Ariz.
91 Q GEM STONES OF THE UNITED STATES ^ ± D

JADE

Jadeite: NaAl(Si03)2 

Nephrite: Ca 2(Mg, Fe)5 (OE)2 (Si40li)2 

Physical properties:

Jadeite Nephrite

(tremolite or actinolite)

Color: Apple green to nearly emerald White to dark green.

green, bluish green, leek green,

greenish white, and nearly white.

Sometimes white containing spots of

bright green.

Crystal form: Monoclinic. Monoclinic. 

Cleavage: Two perfect, at 90°. Two perfect, mutually

inclined at 120°.

Hardness: 6.5-7.0. 6.0-6.5. 

Specific gravity: 3.3-3.5. 2.96-3.10. 

Luster: Subvitreous, pearly on sur- Glistening.

faces of cleavage.

The term jade includes jadeite, a pyroxene; and nephrite, an 

amphibole. Both minerals commonly are green, tough, and 

fibrous. Their toughness is caused by a complex interweaving of 

minute fibrous crystals. Jadeite and nephrite are usually found 

in compact masses and, rarely, in monoclinic crystals. Jadeite, 

the choicer and rarer jade, has a higher specific gravity and degree of hardness than nephrite. The highly prized emerald-green 

color of jadeite is due to the presence of chromium. The green 

shades in nephrite are caused by the presence of ferrous iron. 

The Chinese usually carve it into intricate patterns and use it for 

rings, pendants, pins, and small statues.

Nephrite and jadeite are minerals of metamorphic origin. They 

rarely are found in place, usually occurring in boulders of pebbles 

in stream gravels. Where found in place, nephrite is associated 

with serpentine as rounded masses and with hornblende gneiss and 

schist; jadeite is associated with albite (feldspar) in pegmatite 

dikes that cut dark-green serpentine. Nephrite and jadeite rarely 

are found together. However, in 1950 they both were obtained 

from stream gravels at the North Fork of the Eel River, Trinity 

County, Calif. The most famous nephrite locality in the United 

States is southeast of Lander, Wyo. Other nephrite localities are 

in Marin, Monterey, and Tulare Counties, Calif. Jadeite deposits 

are in Clear Creek, San Benito County, and in Cloverdale and 

Valley Ford, Sonoma County, Calif.

LAPIS LAZULI 

Lazurite: 3NaAlSiC4 - Na£ 

Hauynite: 3NaAlSi04 - CaSO4

Physical properties:

Color: Deep azure blue, greenish blue. 

Crystal form: Isometric.
CONTRIBUTIONS TO ECONOMIC GEOLOGY

Physical properties Continued

Cleavage: Imperfect to distinct dodecahedral. 

_j Hardness: 5-6 (5.5-6.0, hauynite; 5.0-5.5, lazurite). 

| Specific gravity: Variable.

Luster: Vitreous.

Lapis lazuli is a mixture of blue hauynite or lazurite, brassy 

yellow pyrite, and white calcite with minor amounts of diopside 

and mica. Lazurite and hauynite are isomorphous. A higher content of either mineral increases, the value of the lapis lazuli. Because it is too soft to be worn in rings, lapis lazuli is used for 

ornamental purposes, such as amulets, vases, table tops, and 

material for mosaics. It usually occurs in compact, massive 

form and in mottled colors of blue, yellow, and white.

Although the United States contains few deposits of lapis lazuli, 

two mines have yielded the gem; one is in Cascade Canyon, San 

Bernardino County, Calif., and the other is at Italian Mountain, 

Gunnison County, Colo. Lapis lazuli occurs among the crystalline limestone and dolomite that have been altered by heat and 

mineralizing solutions. Hauynite occurs only in igneous rocks 

containing insufficient silica to form feldspars, whereas lazurite 

occurs as a contact metamorphic mineral in limestone near a 

granitic contact.

QUARTZ GROUP

SiO2 

Physical properties:

Varieties:

Coarsely crystalline:

Amethyst (purplish or bluish violet) 

Cat's-eye'or tiger's-eye (chatoyant) 

Citrine (yellow) 

Milky quartz (milky white) 

Quartz with mineral inclusions: 

Aventurine (spangled) 

Gold quartz 

Prase QLeek green) 

Rutilated quartz (fibrous) 

Quartz crystal (colorless) 

Rose quartz (pink)

Smoky quartz, cairngorm (smoky yellow to brownish 

black). 

Cryptocrystalline:

Agate (variegated with alternating bands of color) 

Moss agate (chalcedony with impurities usually 

MnOa in mosslike patterns). 

Onyx 

Carnelian (red chalcedony)

Chrysoprase (apple-green chalcedony)

Heliotrope or bloodstone (green chalcedony with small

red inclusions). 

Jasper (chalcedony colored red by minute inclusions

of hematite).
GEM STONES OF THE UNITED STATES

Physical properties Continued i

Crystal form: Hexagonal. 

Cleavage: None (conchoidal fracture). 

Hardness: 7. 

Specific gravity:

Coarsely crystalline varieties: 2. 65-2. 66.

Cryptocrystalline varieties: 2. 58-2. 64. 

Luster: Vitreous, sometimes greasy, splendent.

The quartz group is divided into two parts: coarsely crystalline varieties composed of silica (Si02), and Cryptocrystalline 

varieties composed of a mixture of minute quartz particles and 

hydrated silica in an amorphous form. The coarsely crystalline 

varieties, rock crystal and amethyst, are cut into gems and the 

Cryptocrystalline varieties, agate and jasper, are used for ornamental purposes.

Quartz has a simple chemical composition: silicon dioxide 

(SiO2). The beautiful colors of amethyst, citrine, and other varieties are caused by traces of metallic oxides in the basic composition. Quartz crystallizes in the rhombohedral division of the 

hexagonal system and is frequently twinned. An X-ray study of 

quartz indicates that its atomic structure is a spiral which causes 

the formation of right- and left-handed crystals. The specific 

gravity is constant in dense quartz but varies in quartz containing 

inclusions or cavities.

Quartz is one of the most abundant minerals in the earth's 

crust. It occurs in igneous rocks that have an excess of silica, 

such as granite, rhyolite, and pegmatite. It also occurs in gneiss 

and schist and may be deposited as vein material by hot silicabearing solutions.

COARSELY CRYSTALLINE VARIETIES

Amethyst ranges in color from pale orchid to deep purple and may 

owe its color to the presence of manganese or boron. The most valuable amethyst is reddish-violet. This gem stone is slightly fluorescent. When heat-treated, the color of some becomes a deep 

brown, then orange, and finally colorless. In the United States, the 

most important amethyst deposits are found in Clayton, Rabun 

County, Ga., and near Holbrook, Navajo County, Ariz. Other localities are in Amherst and Amelia Counties, Va.; Alexander, 

Lincoln, and Macon Counties, N. C.; the Keweenaw Peninsula, 

Mien.'; in Jefferson County, Mont.; and Fremont County, Colo. 

Several minor occurrences have been found in southeastern Pennsylvania; at Pleasant Mountain and Denmark, Maine; at Indianapolis, Ind.;inAbbeville and Anderson Counties, S. C.; atPaterson, 

N. J.; at Granite, Baltimore County, Md.; and in Llano County, Tex.

"Tiger's-eye" is a golden-brown variety of quartz pseudomorphic after crocidolite asbestos. The fibrous structure of the 

asbestos is retained.
222 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Citrine, the golden-yellow, transparent variety of quartz, owes 

its color to the presence of ferric oxide. Localities where citrine 

has been found are the Newman mine, Livermore, Calif.; at 

Tuscarora, Elko County, and Gold Mountain and Palmetto Canyon, 

Esmeralda County, Nev., and at Stony Point and Taylorsville in 

Alexander County, N. C.

Milky quartz is a translucent to opaque, white variety. It is a 

common vein mineral in igneous and metamorphic rocks. The 

color of milky quartz is the result of many tiny inclusions of 

water and liquid carbon dioxide and fractures; the apparent white 

color is caused by the reflection of light by the walls of the cavities. The milky color may be tinted red, yellow, yellowish brown, 

or bluish gray. In Buckfield, Maine, milky quartz crystals were 

found in one of the largest pockets of quartz crystals ever discovered in the United States (Dake, Fleener, and Wilson, 1938, 

p. 107). Boulders of milky quartz have been found in the glacial 

drift of Illinois and other North Central States.

The term quartz with mineral inclusions pertains to all varieties of quartz that contain other minerals. Quartz may include 

such minerals as rutile, tourmaline, hornblende, epidote, actinolite, goethite, and many others because it is usually the last 

mineral to crystallize from a magma. The included crystals give 

a netlike or hairlike appearance to the stone. All varieties of 

quartz with rodlike inclusions are called sagenite; the included 

mineral is used in the name of the particular variety of sagenite. 

If rutile is included, the stone is known as "rutilated quartz;" if 

tourmaline is included, it is known as "tourmalinated quartz." 

Prase is a dull leek-green quartz containing actinolite inclusions. 

The finest domestic rutilated quartz was" found in boulders near 

Hanover, N. H. Other localities are at Florissant, Colo.; in 

Alexander, Burke, Catawba, Iredell, and Randolph Counties, 

N. C.; Amelia Court House, Va.; Lancaster County, Pa.; and the 

Calumet Hill Quarry, Cumberland, R. I. Tourmalinated quartz 

has been found at Paris, Maine, and-Stony Point, N. C.

Quartz with spangled inclusions is known as aventurine. The 

included minerals are scales of shiny mica or hematite. The most 

familiar aventurine is of reddish-yellow color and has a coppery 

sheen. Only small quantities of aventurine have been found in the 

United States.

Native gold may occur as disseminated growths in crystalline 

quartz, chalcedony, and agate. Gold in translucent, white, or 

clear quartz has been found in Butt-e, Calaveras, El Dorado, 

Mariposa, Nevada, Placer, Sierra, Tuolumne, and YubaCounties, 

Calif. Gold in chalcedony was obtained from the Republic mining 

district, Washington. An unusual deposit of gold in quartz with 

malachite was discovered at the Quartet mine, near Searchlight, 

Nev. Gold in black quartz has been found at the Sheep Ranch mine, 

Calaveras County, and Sutter Creek, Amador County, Calif.

Quartz crystal is the transparent, colorless variety of quartz. 

The two best-known localities of quartz crystal in the United States 

are near Hot Springs, Ark., and in Herkimer County, N. Y.
GEM STONES OF THE UNITED STATES

In New York the crystals are commonly found in the soil above 

large cavities containing doubly terminating crystals. Most of 

the Herkimer County crystals were obtained from Middleville, 

Newport, and Little Falls, N. Y. In Saline, Garland, and Montgomery Counties, Ark., quartz crystals occur in the lining of 

cavities in sandstone and massive quartz. Other localities where 

quartz crystal has been found are Diamond Island, Portland 

Harbor, Maine; Diamond Hill and Cumberland Hill, R. I.; in 

Alexander, Burke, Catawba, and Surrey Counties, N. C.; Rome, 

Georgia; in Madison County, Ark.; Fayette County, Tex.; and 

South Royalton, Vt. Quartz crystal is common and has been 

found in nearly all States.

Rose quartz, the rose-red or pink massive variety of quartz 

owes its color to the presence of manganese or titanium; this variety rarely occurs in crystal form. The only known discoveries 

of rose quartz crystals in the United States were made at Paris 

and Newry, Maine, and Grand Rapids, Mich. (Dake, Fleener, and 

Wilson, 1938, p. 108). Rose quartz commonly occurs as partly 

translucent masses in pegmatite veins. One of the largest deposits 

is located in the Black Hills, near Custer, S» Dak. Other localities are Albany, Maine; Southbury, Conn.; Westchester, N. Y.; 

Ashe and Stokes Counties, N. C.; Roaring Fork, Pitkin County, 

Colo.; and Tuscarora, Moray, Carlin, and Silver Peak, Nev. 

Current production is from the Black Hills region, S. Dak., and 

the Pala, Mesa Grande, and Ramona districts, San Diego County, 

Calif.

Smoky quartz is the smoky-yellow to dark smoky-brown variety 

of coarsely crystalline quartz. Cairngorm is the smoky-yellow 

quartz made famous in Scotland. Its smoky appearance is thought 

to be the result of radium exposure to colorless quartz crystals 

(Dake, Fleener, and Wilson, 1938, p. 92). The best known locality in the United States for smoky quartz probably is the Pikes Peak 

region in Colorado where the crystals occur in association with 

amazonite and other gem stones in pockets of coarse granite. 

Other localities are Mount Antero summit, Colo.; Helena, Mont.; 

Alexander, Burke, and Catawba Counties, N.C.; Herkimer County, 

N. Y.; Goshen, Mass.; Blueberry Hill, in Stoneham, Minot, and 

Mount Pleasant in Maine; Montgomery County, Pa.; Iron Mountain, 

Missouri; and Magnet Cove, Arkansas.

CRYPTOCRYSTALLINE VARIETIES

All cryptocrystalline varieties are a form of chalcedony, the 

general term applied to gray or dark masses of silica that are almost opaque. Cryptocrystalline varieties of quartz are tougher 

than the coarsely crystalline varieties because they are composed 

of many closely bound small crystals and amorphous particles. 

Hardness and specific gravity also vary slightly in the cryptocrystalline group.

Agate is variegated chalcedony containing colorful bands in a 

concentric arrangement. The most common colors of agate are

412673 O - 57 - 4
CONTRIBUTIONS TO ECONOMIC GEOLOGY

red, yellow, brown, green, blue, gray, and black. These colors 

are the result of the presence of small amounts of metallic salts 

or iron or manganese oxides and, rarely, nickel, chromium, and 

copper. The luster is sometimes waxy. Varieties of agate are: 

"banded agate, " bands appearing three-dimensional and arranged 

in a wall-within-wall structure; "moss agate, " dendritic patterns 

of manganese dioxide, iron oxide, or chlorite fibers included in 

white or clear masses of silica; "iris agate," apparently colorless 

until proper light reveals rainbow colors caused by the diffraction 

of light from closely spaced parallel layers; and silicified trees. 

Onyx is opaque agate with parallel alternating layers of different 

colors; the layers are straight lines of uniform thickness. Onyx 

shouldnotbe confused with Mexican onyx, a banded marble. Agate 

is a secondary mineral that fills seams, fissures, veins, and cavities in rock. It may also occur as stalactitic and botryoidal 

growths. Most agates are found in gravel deposits. The most 

important States where agates are obtained are central and eastern Oregon, Montana, Wyoming, Arizona, Texas, New Mexico, 

Washington, Utah, and Illinois. For exact localities consult The 

Agate Book, by H. C. Dake.

Carnelian or sard is a clear, translucent agate ranging in color 

from yellow to red. It has been found in Jenne Creek, Hornbrook, 

Calif.; Salmon River and Cedar Creek, near Toledo, Oreg.; and 

in the Nehalem River, Vernonia, Oreg.

Chrysoprase is the apple-green, translucent variety of chalcedony. The color may range from bluish green to yellowish 

green, the result of the presence of nickel. Chrysoprase is usually associated with silicified nickel deposits. Because nickel 

deposits are scarce in the United States, Chrysoprase is rare. 

Localities where it has been found are Nickel Mountain in western 

Oregon; near Vis alia, Calif.; Buncombe and Macon Counties, N0 C.; 

Chester County, Pa.; Gar field County, Colo.jSt. Lawrence County, 

N. Y.; and Gila and Mohave Counties, Ariz.

Heliotrope or bloodstone is dark green, translucent chalcedony 

containing blood-red spots of jasper. The green color is due to 

chlorite and possibly iron, and the red color, to hematite. The 

few occurrences of heliotrope in the United States are at Newport 

Beach, Oreg.; in Chatham County, Ga. jnearUncompahgre, Colo.; 

and in Albany and Orange Counties, N. Y.

The term jasper includes nearly ail varieties of impure, opaque, 

colored, amorphous quartz. Jasper may be red, yellow, brown, 

green, Wulsh; or black. These colors are due to minute inclusions of imparities; for example, irOn. JaSp6f ]S fOUIied lH Veins 

near lava BLOWS. However, it is usually obtained from gravel deposits far from its original locality. It is widely distributed in 

the United States, especially in the Western States. The largest 

jasper deposit in the world is in the Petrified Forest, Ariz. One 

of the most famous jasper localities is the Morgan Hill district, 

Santa Clara County, Calif. Here the jasper is bright red containing circular areas of white and gray, and therefore is known as
GEM STONES OF THE UNITED STATES 225

orbicular jasper. Other localities are Collyer, Trego County, 

Kans.; Berkshire Hills, Rowley, and Chester, Mass.; and along 

the Hudson River in Orange County, N. Y. In Pennsylvania many 

specimens have been found along the Delaware and Schuylkill 

Rivers, near Reading; in Chester and Lancaster Counties; and 

near Bethlehem and at Jim Thorpe (Mauch Chunk). In North 

Carolina jasper has been found at Granville; Reed's Creek, 

Madison County; and in Moore and Wake Counties. Jasper has 

also been found near Sullivan City and Laredo, Tex.; San Bernardino andShastaCounties, Calif.; and near Morrison, HotSpring 

County, Ark.

OPAL 

SiO2' n Hp

Physical properties:

Varieties: White opal, black opal, fire opal (reddish or orange),

water opal (colorless), hydrophane. 

Crystal form: None (amorphous). 

Cleavage: None (conchoidal fracture). 

Hardness: 5.5-6.5. 

Specific gravity: 1.9-2. 3. 

Luster: Vitreous to resinous pearly (common opal is waxy).

Opal may be precious but most varieties are semiprecious. It 

is asemitransparent stone having a vivid display of colors. When 

pure, opal is colorless; when impure, it may be red, yellow, 

green, blue, or black. It is an amorphous form of hydrated silica 

containing varying amounts of water. It is composed of a series 

of very thin films or layers which differ in refractivity. Opal appears to be a solidified mass of milky glass, but when light strikes 

the stone at certain angles, flashing colors are revealed. This 

phenomenon is known as opalescence. The colors are believed 

to be caused by the different refractivities of light in the thin 

layers; the thinner and more uniform the layers, the more beautiful the colors. Opal is a soft gem stone and therefore must be 

worn with care. Hydrophane, the opaque variety of common opal, 

is very porous and will absorb any liquid. Other varieties are 

less porous but will absorb some liquid. Wearers of opal should 

keep the stone away from dirty water, ink, or colored fluids. 

Heat evaporates the water in opal and therefore causes the stone 

to shatter or to lose its color. The value of opal is determined by its principal color, uniformity of structure, and beauty 

of opalescence. True black opals with good opalescence are the 

most valuable.

Opal occurs as a secondary mineral associated with volcanic 

rocks. It is also found in seams and fissures of sedimentary, 

igneous, and metamorphic rocks. The forms of opal range from 

massive, botryoidal, stalactitic to earthy, depending upon how the 

silica was deposited. Very little precious opal has been found in 

the United States, but common opal has been obtained from New 

York, New Jersey, North Carolina, Georgia, Florida, and Oregon.
226 CONTRIBUTIONS TO ECONOMIC GEOLOGY

The best-known deposit of precious opal in the United States is in 

Virgin Valley, Humboldt County, Nev. The opals are obtained 

from thin seams of volcanic ash in the bottom of a Tertiary lake. 

The gem material occurs as opalized wood which appears to be 

driftwood that was covered by volcanic ash and completely petrified by opaline solutions. The greatest variety of opals in the 

world is found here (Dake, Fleener, and Wilson, 1938, p. 249). 

Other localities for precious opal in the United States are in 

lava flows of the Columbia Plateaus in Washington, Idaho, and 

Oregon.

SPODUMENE 

Kunzite and hiddenite

LiAl(Si03 )2 

Physical properties:

Varieties: Kunzite (bluish pink to lilac pink), hiddenite (emerald 

green).

Crystal form: Monoclinic.

Cleavage: Two perfect, prismatic cleavages and one good parting.

Hardness: 6.5-7.0.

Specific gravity: 3.13-3. 20.

Luster: Vitreous.

Kunzite and hiddenite are the rare, transparent varieties of 

spodumene. Kunzite ranges in color from bluish pink to lilac 

pink; hiddenite ranges in color from yellowish green to emerald 

green. The color of kunzite fades upon long exposure to light. 

Common spodumene is white, yellow, or green. Spodumene usually occurs as deeply striated, monoclinic prisms that are often 

twinned. Most spodumene is opaque. Perhaps the rapid weathering of spodumene explains the reason so few deposits of its gem 

varieties have been found.

Spodumene occurs in very large crystals in pegmatite dikes. 

The most notable locality for kunzite is in the Pala district, San 

Diego County, Calif. The gem occurs with other lithia minerals 

in a series of broad, uniform pegmatite dikes. Kunzite is found 

in the core of the pegmatite, generally in a very coarse-grained 

quartz-spodumene unit. Quartz is the common associate, but 

cleavelandite, muscovite, and lepidolite also are found with it. 

Gem-quality crystals usually are enclosed in clay and a few occur 

loose at the bottom of voids or pockets. Most gem crystals are less 

than 2 inches long but some are nearly 15 inches long and weigh 

24 ounces or more. Kunzite also has been found at Cohuila Mountain, Riverside County, Calif.; Spruce Pine, N. C.; Branchville, 

Conn.; and Andover, Maine.

The first reported locality for hiddenite in the United States is 

Stony Point, Alexander County, N. C. It has Since been found in 

pegmatites of the Black Hills, S. Dak. It occurs with emerald and 

quartz in pockets of pegmatite dikes (see p. 210).
991 GEM STONES OF THE UNITED STATES ^ '

TOPAZ 

[Al(F,OH)2]AlSiO4

Physical properties:

Color:' Colorless and pale brown, blue, and pinkish shades of 

yellow.

Crystal form: Orthorhombic.

Cleavage: Perfect, parallel to basal face.

Hardness: 8.

Specific gravity: 3.4-3.6.

Luster: Vitreous.

The most prized colors in topaz are reddish pink and wine yellow. The natural reddish-pink topaz is very rare. However, 

brownish-yellow topaz from Brazil may easily be transformed to 

a pink shade by application of heat. The pink color is permanent 

because the heat changes the atomic structure of topaz. Application of heat is most effective on Brazilian stones. Topaz may 

contain inclusions of liquid carbon dioxide. Yellow topaz is faintly 

dichroic and pink topaz is very dichroic in reddish-yellow and 

pinkish-yellow shades. Gem topaz is transparent and vitreous, 

but not brilliant. The stone must be handled carefully by the gem 

cutter, and it is usually brilliant-cut in front and step-cut in 

back.

Topaz occurs in pegmatite dikes and in cavities in granite. It 

is formed by the action of hot acid vapors on rocks rich in aluminum silicates. It is commonly associated with minerals of similar 

origin such as fluorite, cass'iterite, and tourmaline. Colorless 

and bluish transparent topaz has been found in California, Colorado, 

Utah, and New Hampshire. In San Diego County, Calif., both blue 

and yellow varieties have been found; colorless and sherry-brown 

topazes were obtained in the Thomas Mountain district of Utah. 

Other localities are Nathrop, Colo.; Tarryall Mountains, north of 

Lake George, Colo.; North Chatham, N. H.; Streeter, Mason 

County, Tex.; and Topsham, Maine.

TOURMALINE

(Complex sodium-aluminum borosilicate) 

Physical properties:

Varieties: Achroite (colorless), indicolite (indigo blue), rubellite

(reddish), siberite (violet red), schorl (black). 

Crystal form: Hexagonal. 

Cleavage: None. 

Hardness: 7.0-7.5. 

Specific gravity: 2. 98-3. 20. 

Luster: Vitreous to resinous.

Tourmaline occurs in a great variety of colors ranging from rose 

red (rubellite) and violet red (siberite) to indigo blue (indicolite), 

green, yellow, brown, and black (schorl). A colorless variety 

known as achroite is very rare. Tourmaline may have more than 

one color in a single crystal. If so, the colors usually are strongly 

contrasting and in many crystals have abrupt boundaries. The
228 CONTRIBUTIONS TO ECONOMIC GEOLOGY

colors may be separated in a plane perpendicular to the length of 

the crystal or arranged in cylindrical zones. Watermelon tourmaline, having a pink core and green exterior, is an example of 

cylindrical color arrangement. In some crystals, the colors are 

reversed. Tourmaline is found in almost every color except sapphire blue and emerald green. The chemical composition of 

tourmaline is a complex borosilicate containing varying amounts 

of sodium, potassium, calcium, magnesium, lithium, fluorine, 

and hydrogen. On the basis of its composition tourmaline may be 

divided into three types which grade into one another:

1. Alkali tourmaline containing sodium, potassium, and lithium. Example, rubellite. 

2* Magnesium tourmaline containing.much;magnesium. Example, achroite

and brown varieties. 

3. Iron tourmaline containing much iron. Example, schorl.

Vitreous, clear, and transparent alkali tourmalines furnish the 

best gem material. The prismatic crystals are striated and have 

a different type of termination at each end. In cross section the 

crystals have a rounded, triangular shape. Dichroism is strong 

in the brown and green varieties. In order to permit the maximum 

amount of light to enter the stone, most tourmaline must be cut 

so that a facet perpendicular to the table is nearly at right angles 

to the length of the crystal.' Tourmaline is usually brilliant-cut 

in front and step-cut in back; fibrous varieties are cut en cabochon 

to display their chatoyancy (cat's-eye effect). Fractures are 

common in many tourmalines. The specific gravity varies with 

the color: the specific gravity of red stones ranges from 3.01 to 

3.06, and of black stones, from 3.11 to 3.20. Tourmaline is 

fairly soft and therefore should not be set in a ring.

Tourmaline occurs as an accessory mineral in the acidic rocks, 

granite and pegmatite; and in the metamorphic rocks, schist and 

crystalline limestone. It is formed at high temperatures and pressures in the presence of vapors high in boron and fluorine. Rubellite, 

the lithia tourmaline, is usually associated with lithia-bearing muscovite and lepidolite. Most varieties of tourmaline occur in pegmatite deposits where they are associated with feldspar, quartz, and 

muscovite. The magnesian tourmaline, however, is found in limestone. Black tourmaline is a common accessory mineral in metamorphic rocks. In the United States excellent gerri tourmaline has 

been found in the Pala, Mesa Grande, Rincon, and Ramona districts, 

San Diego County, Calif.; and at Mount Mica near Paris, at Mount 

Apatite near Auburn, Mount Rubellite, Rumford Falls, andHebron,

Maine. Other gem tourmaline localities in the United States are 

Royal Gorge and Pikes Peak districts, Colo.; Riverside County, 

Calif.; and Haddam, Conn. Dark-colored tourmaline crystals have 

been obtained fromCochise,Coconino, Maricopa, Pima, Pinal, Yavapai, and Yuma Counties, Ariz.; Chesterfield and Goshen, Mass.; 

Gouverneur, Dekalb, and Pierrepont, N. Y.; and Chester County, Pa. 

In San Diego County, Calif., many transparent tourmaline crystals of green, blue, yellow, and red were obtained from pockets 

in pegmatite dikes. Kunzite is associated with the tourmaline.
GEM STONES OF THE UNITED STATES 229

TURQUOISE

CuO 3Al2Og. 2P2 05 9H20

Physical properties:

Color: Blue, blue green, green.

Crystal form: Triclinic.

Hardness: 6.

Specific gravity: 2. 60-2. 83 (not constant due to porosity).

Luster: Waxy.

Turquoise, the favorite gem stone of the American Indians, is 

an opaque mineral ranging in color from sky blue to bluish green 

to green. The preferred color, sky blue, is typical of specimens 

containing no iron; the greenish shades are due to the presence of 

iron. Turquoise usually occurs in compact, cryptocrystalline 

masses. It has a porous structure and therefore should be protected from grease, moisture, and dirt. Sunlight and heat also 

have destructive effects on the stone. It is a fairly soft, yet tough, 

gem stone and is usually cut en cabochon and mounted in brooches, 

earrings, necklaces, and rings.

Turquoise is a secondary mineral found in thin veins and small 

masses in highly altered rocks. It is associated with limonite, 

quartz, feldspar, sericite, and kaolin. In the United States most 

of the sky blue turquoise deposits have been mined out, but greenish stones are still being obtained from localities in Arizona, 

New Mexico, and Colorado. At Turquoise Mountain and Ithaca 

Peak^ Mineral Park, Ariz. , turquoise is found in joints and fissures'of a highly kaolinized quartz porphyry. Some of the turquoise 

appears to have been deposited from hot solutions in the quartz 

porphyry and others seem to be replacements of feldspar and 

kaolin. In the Castle Dome mine, Gila County, Ariz. , turquoise 

is found in the leached zone of the porphyry copper deposit. In 

New Mexico the most notable locality is at Los Cerrillos, Santa 

Fe County, where turquoise is found in thin veins and small nuggets in a yellowish-white tuff aceous rock with gold-bearing quartz. 

Other New Mexico localities are in the Burro Mountains near 

Silver City, Little Hachita Mountains, Grant County, and the 

Jarilla Mountains, Otero County. The largest turquoise deposits 

in the United States are in the King mine of the San Luis Valley, 

Colo. Other localities are Tombstone, Cochise County and Pierce, 

Maricopa County, Ariz. ; near Baker, San Bernardino County, and 

Chowchilla River, Fresno County, Calif. ;Lake and Mineral Counties, Colo. ; Esmeralda County, Battle Mountain, Lander County 

and Tonopah, Nye County, Nev. ; Somerville, N. J. ; andCulberson 

County, Tex. In the United States the only known crystals of turquoise were found in Campbell County, Va.

OTHER COPPER GEM MINERALS

Chemical composition-- 

Physical properties: 

Color ------------

Azurite

2CuCO3. Cu(OH)2 

Various shades of

azure blue.

Malachite

CuCO3. Cu(OH}2 

Bright green 

Cbrys ocolla

CuSiO3' 2KP 

Green to greenish

blue to blue.
230 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

Azurite

Physical properties Cc

^ p-tTO-l-Ql f(^T*TYY

f^~\ OQTTQrTO

TTo VC^TIOQQ

Specific gravity- -

>ntinued:

Two indistinct 

3.5-4.0 

3. 77-3. 89 

Vitreous, almost 

adamantine.

Malachite

Perfect basal --

3.5-4.0 

3. 90-4. 03 

Adamantine to 

vitreous, silky, 

dull.

C h ry s oc o I la

Cryptocrystalline. 

None, conchoidal 

fracture. 

2-4. 

2.00-2.24. 

Vitreous, shining, 

earthy.

Azurite, the azure-blue copper carbonate, occurs in prismatic 

crystals and radiating spherical groups. It is similar in composition to the green copper carbonate, malachite. Both stones are 

soft and opaque. Azurite has a lower specific gravity than malachite and is not as common. It is a secondary mineral found in 

oxidized parts of copper veins with malachite, cuprite, native 

copper, iron oxides, and various sulfides of copper and.iron. 

The country rock is commonly limestone. Localities in the United 

States where gem azurite has been found are at the Copper Queen 

mine in Bisbee, Courtland, Mineral Park, Morenci, and Superior, 

Ariz.; Las Vegas, Nev.; and the La Sal district, Utah.

Malachite is bright green in color and commonly occurs inbotryoidal or stalactitic masses. It rarely is found in well-formed 

crystals, but it maybe pseudomorphous after azurite. Malachite has 

a perfectbasal cleavage. Its luster varies from adamantine to vitreous in crystals, silkyin fibrous types, and dull in earthy varieties. The geologic occurrence and localities of malachite are the 

same as azurite. Both minerals are used for ornamental purposes.

Chrysocolla, a hydrous copper silicate, ranges in color from 

green to greenish blue. It is amorphous and usually occurs in 

opaque, compact masses. Its chemical composition is variable. 

It is distinguished from turquoise by inferior hardness. It may 

have avitreous or earthy luster. ChrysocoUa also is a secondary 

mineral found in oxidized zones of copper veins. Common associates are azurite, malachite, and other copper minerals. It is

found in the copper districts of Arizona and New Mexico.

A list of journals on gems is given below:

Pacific Mineralogist, 6731 Arbutus Ave., Huntington

Park, Calif, (ceased). 

The Mineralogist, Couch Bldg., Portland, Oreg. (monthly).

The Earth Science Digest. Revere, MaSS. (mOnthly). 

Gems and Gemmology, Gemmological Inst. America,

Los Angeles (quarterly). 

The Gemmologist, National Assoc. of Goldsmiths Press,

London (monthly). 

The Lapidary Journal, Lapidary Journal, inc., p. o.

Box 1228, Hollywood 28, Calif, (quarterly).

The Mineral Hobbyist, State Mineral Soc. of Texas, 

Austin, Tex. (ceased).

Rocks and Minerals, Rocks and Minerals Assoc., Peekskill, N. Y. (6 times a year).
GEM STONES OF THE UNITED STATES 231

GEOGRAPHIC DISTRIBUTION OF DEPOSITS OF PRINCIPAL

GEM STONES

State and county

Alabama:

Marshall.-----.--.....-......-..-.

TQ! 1 annncia

Arizona:

Gila .......................................................

Greenlee

Mohave - --

Navajo -. .. -

"Dl TY1 O

TDinal

*VQTrQT\Q 1

Uma - ....... ....... .... ....... ..... .... ....... .......

Arkansas: 

Garland ..........................................

Hot Spring 

Madison...........-.-.-.....- ........

T3i Iro

California:

AT o yyi oHQ

Locality

Rockford---- . .. 

Hissop .......... ............

Guntersville ......... ......

Ganada ..... ... 

Navajo reservation 

Buehl Park, Fort Defiance. 

Petrified Forest

Cochise County 

Copper Queen mine, 

Bisbee.

Courtland -. ..... ..... .......

Tombstone 

Castle Dome mine 

Globe- --- . . 

Inspiration mine - Graham County. 

Graham Mountain 

Morenci

Maricopa County - 

Aquila .-.-....... . 

Pierce.

Aquarius Mountains,

Owens. 

Black Mountains 

Ithaca Peak, and Aztec 

Mountain, Mineral Park.

Holbrook-- ----------

Kelvin---------------

Saddle Mountain 

Yavapai CountyUma County 

TOCJCM oiH 1 1 o

Magnet Cove .......... ..

T^ol Q no-rr

"Do T'M'n

Gem stone

Gem beryl. 

Do.

Quartz crystal.

Pyrope. 

Do.

Do.

"DofyM "fi oH xxrt"M"\H TQC;T\OT»

Tourmaline.

Azurite.

TS 1 T* /"11 1 /"I T C O Q (711T*l'fo

Turquoise.

Tourmaline.

Turquoise.

(** VlT*"\7QrM^T*3 QO

Dn

A rrQ'f'O

Uvarovite.

A ^ITPlto

Agate, tourmaline. 

Chalcedony.

OVi ) » » TO("vr\7«Q co cn^nc! Qii _

larite. 

Turquoise.

Do.

Chalcedony, opal.

f*Vl Y¥ X7Q.OT"\T'Q QO

Chrysoprase, jasper, 

turquoise, azurite.

Amethyst, petrified

wood. 

Tourmaline.

Turquoise , tourmaline.

Tourmaline.

Do.

Quartz crystal.

Smoky quartz, quartz 

crystal, sunstone, 

topazolite.

To Qr^OT*

Do.

f^iiO T*t "7 I*"*"?* WQfal

Agate thunder eggs.
232 CONTRIBUTIONS TO ECONOMIC GEOLOGY

?able Continued

State and county

California Continued 

Alameda Continued

A 1 T^I no

Butte.-.----^- -

r^Ql QTTOT*Q Q

El Dorado.. - 

Inyo - -- 

T EJ Iro

Mariposa»."-«»»»««-»»«-««-».-»-.

Mont©r6y

"KToTrci HQ

T? T Trp T» o i rl p

San Benito 

Locality

Newman mine, Livermore. 

Hope Valley, Mogul,

Monitor districts.

Shake Ridge, Volcano -

Butte County -.

Cherokee Flats, Yankee 

Hill, and Oroville. 

Feather River

Garnet Hill ... -

Green Mountain mine, 

Chile Gulch, Mokelumne Hill.

Smith River 

El Dorado County------

"D] Q /^OT*Tn 1 1 O

Webber Hill-- ----- -

Taylor's Ranch, Chowchilla River.

"IT1 r» ci n c* Vi 1 oH^ T^'iiT'olrQ HTQ 

trict.

Kern County 

Howard Springs.- -- 

A /^f f~\Y\

Orjnool -i4-^\

Mariposa County. -----

T^ypTl r^Vl ^(^T^T^Q!

Green Valley, American 

River. 

Gopher Hill --------

Laura quartz, mine, 

Clio.

Spanish Creek -- ---

Cohuila Mountain--------

r^ipQT* r^T»Poir

San Bernardino CountyGem stone

Citrine. 

Rose quartz.

Diamond.

A TYl of VtWQf Y*^iQP miQ T*t <7

smoky quartz, diamond. 

Black gold quartz.

Gold quartz.

Diamond. 

Smoky quartz.

AnHyQ^iTO

Quartz crystal. 

Jasper.

Black gold quartz.

Smoky quartz, diamond.

lapis lazuli, opal.

Amethyst.

To QTlOY*

Nephrite .

TQ OT"VOT»

Gold quartz.

Gold quartz.

Uvarovite. 

Diamond.

Opal.

Diamond.

yl, kunzite , smoky 

quartz, quartz crystal, rose quartz, tourmaline .

rose quartz. 

Jadeite, uvarovite.

Opal, sapphire.
GEM STONES OF THE UNITED STATES 233

Table C ontinued

State and county

California Continued 

Sari Bernardino Cont.

San Diego . .. 

Santa Clara--- ---- -

OV»o c-f o

CS OT'T'Q

Siskiyou -- -- 

Trinity--------------

Tiilar-A

Yuba ---- --- .

Colorado: 

Alamosa------ -------

Boulder --- -- - - 

OJ-ioffoo

Locality

Brown Mountain...................

TVToQT* molroT*

Cottonwood StationrioatVi TT'alloTr

San Bernardino Mountains . 

Victor-......-... ...........................

Dos Cabezas Springs 

Mesa Grande district-... 

"Do! o Hi cfT*ir»f

Good Hope mine-------

Ramona -- -

Rincon - 

Land's End Station- -

Santa BarbaraHart------ -

Dunsmuir -- - .

Jenne Creek, HornbrookCloverdale and Valley 

Ford. 

North fork of the Eel 

River . 

Trinity River 

Tulare County 

"Di"iT*t PTMril 1 P

T^QttlpQna Ifp f^ypplf

Tobias Mountain, Exeter, Yokohol. 

Venice Hill, Visalia -----

TQ r* IfQ j \ Y\ T H 11 O

Yuba CountyKing Mine, San Luis 

Valley.

T^PP"pf>*Q 1 1

Boulder County 

Calumet iron mine, Turret.

Gem stone

Bloodstone. 

Lapis lazuli. 

Turquoise. 

Turquoise. 

Bloodstone. 

Agate.

Turquoise. 

Aquamarine, essonite, 

kunzite, jasper, golden 

and green beryl, morganite, rose quartz, 

quartz crystal, tourmaline, topaz, spessartite. 

Essonite. 

Rose quartz, tourmaline. 

Golden beryl, rose 

quartz, kunzite, tourmaline. 

Grossularite. 

Aquamarine, rose 

quartz, tourmaline. 

Tourmaline . 

Jasper. 

Quartz crystal. 

Jasper. 

Do. 

Gold quartz. 

Garnet, opal. 

Sard. 

Jadeite.

Jadeite, nephrite.

Diamond. 

Nephrite . 

Diamond. 

Rose quartz. 

Chrysoprase. 

Pyrope . 

Rose quartz.

Chrysoprase. 

Gold quartz. 

Uvarovite . 

Gold quartz.

Turquoise.

Amazonite . 

Chrysoberyl. 

Essonite, quartz crystal, sapphire, sagenite.
234 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

Colorado Continued 

Chaf fee Continued

fMoav f^T*pplr

Conejos- -- -- - - 

r"1 ! 1 Ct OT*

V\ "Dao/"i

Garfield----- ---- -

Gilpin 

Locality

Calumet mine, Salida - 

Chalk Creek, Buena VistaDorothy Hill, Ruby Mountain area, Nathrop.

Mount Antero, Sawatch 

Range.

Nathrop- - - 

Red Elephant Mountain, 

Lawson. 

Silver and Trail Creeks, 

Idaho Springs. 

King turquoise mine, 

Manassa.

Devils Head -----------

Pine Creek Store near 

Sedalia. 

El Paso County--------

Austin Bluffs, Colorado 

Springs .

Pvucfal TDo-rlr

Manitou Springs 

St Peter's Dome

Near Calumet- ...

Canon City-- 

Chalk Mountain, Fremont Pass. 

Curio Hill, Wet Mountains . 

Garden Park near Canon 

City.

"Do Y»lrHa1 o

Royal Gorge-- 

'"PovEi c r^T*oolr

Garfield County 

Central City.--- ------

Italian Mountain, Crested Buttes in the Sawatch 

Range. 

Mount Beckwith--- ---.

Centennial Cone, GoldenDrew Hill, Golden------

Turquois Chief mine, St.

Kevin mining district,

Leadville. 

Pennoyer amethyst 

mine, Red Feather 

Lakes, Fort Collins.

Gem stone

Ruby. 

Sapphire . 

Quartz crystal, almandite , spessartite, topaz. 

Aquamarine , quartz 

crystal, smoky 

quartz, topaz. 

Topaz. 

Amethyst.

Do. 

Turquoise .

Amazonite . 

Amazonite, smoky 

quartz, topaz. 

Quartz crystal, amazonite, smoky quartz. 

Petrified wood. 

Carnelian, jasper.

Amethyst , tour maline. 

Amazonite, topaz. 

Smoky quartz. 

Amazonite, quartz 

crystal, smoky 

quartz, topaz. 

Sapphire . 

Almandite, amethyst, 

opal, rose quartz. 

Spessartite, topaz, 

smoky quartz. 

Agate.

Jasper ized bones, agate. 

Aquamarine . 

Aquamarine, tourmaline. 

Rose quartz, gem beryl. 

Chrysoprase. 

Labradorite. 

Lapis lazuli.

Moonstone. 

Gem beryl, smoky 

quartz . 

Chrysoberyl. 

Turquoise .

Amethyst.
GEM STONES OF THE UNITED STATES 235

Table Continued

State and county

Colorado Continued 

Larimer Continued

TVA^QJl

Montrose -- 

Coiray--- ------------

TSavlr

Oifb-in

Rio Grande ...... ..-.... ............

CJo miQ r*Ho

Teller...:.-............. ...................

Connecticut: 

Fairfield . - -- .... .....-

Litchfield --------- - 

Middlesex -----------

New Haven -

Windham-- -

Georgia: 

Bulloch- - . .... .

Chatham----- --- -

Clay - 

Clayton------ --------

Fannin ...... ... ..............

Locality

Specimen Mountain, 

Rocky Mountain National Park.

ni Q H o OQ T» lr

Opal Hill, Fruita -----

Pinon mesa .

Amethyst mine, Bachelor 

Mountain, Creede. 

West Willow Creek, 

North Creede. 

Wolf Creek Pass, San 

Juan Mountains. 

Near Uncompahgre .........

Mount Sneff els .........................

Agate Plateau, Buffey........ 

Mount Antero summit-- 

Old Salt Works, Antero 

Junction. 

South Park, near Grand 

River. 

Tarryall Mountains ............

Roaring Fork, near 

Clear Creek and Bear 

Creek. 

Del Norte

Hall turquoise mine, 

Villagrove .

f""1 Y»iy\r^1 Q C^~r*&O\T Q T»OQ

Crystal Peak, F 1 o r i s - 

sant.

Trumbull . ...

Haddam -- ...............

Portland- -----------

New Haven .................. ............

Southbury ................................

Willimantic -

Bulloch County 

Chatham County 

Clay County ...........................

Morrow Station ..................

Fannin Countv..........................

Gem stone

Agate, geodes, onyx, 

opal, jasper.

Opalized wood. 

Do. 

Banded and moss agate, 

chalcedony. 

Amethyst.

Amethyst, turquoise 

matrix. 

Agate, moonstone.

Heliotrope. 

Andradite-topazolite . 

Agate. 

Smoky quartz. 

Chalcedony, bloodstone, moss agate. 

Almandite, heliotrope.

Amazonite, smoky 

quartz, topaz. 

Rose quartz.

Plume agate , chalcedony, opal, quartz 

crystal. 

Turquoise.

Do. 

Amethyst, quartz crystal, smoky quartz, 

geodes, sagenite, amazonite, topaz, garnet, 

rutilated quartz.

Kunzite . 

Tourmaline . 

Topaz . 

Aquamarine , golden 

beryl. 

Aquamarine, chrysoberyl, spessartite, 

tourmaline . 

Aquamarine, tourmaline. 

Andradite. 

Rose quartz. 

Topaz.

Fire opal. 

Heliotrope . 

Diamond. 

Do. 

Malap.hit.e
236 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

Georgia Continued 

FloydFranklin--- 

Hall .............................................. .

Rabun---- --- - 

Towns--.... .

Union----.-- -- -----

Washington-.. , 

Idaho:

AHa

A HQ YT\ <z

T^OQT* T Q Iro

Blaine ------ -----.

Boise- ...........-..-.....- .............

("M OQ TMX7Q toT*

(^llQtpT1

T QtoVi

Lemhi . ................ .......................

Nez Perce- -- "

Oneida--- - ---------

Owyhee.---- -- -..

Shoshone .............. .................

Washington ...................................

Indiana:

Marion ................................... .....

Iowa: 

DCS l^IoinGs

Story--. 

Vdll DUiCil 

Kansas: 

Trego ................... .................................

Kentucky:

Elliott ..................................

Maine: 

Androscoggin-- -----

Locality

Gainesville -- ---.---.

"Ri i *"* TrVi o Q H

Ledbettermine, Clayton 

and Highland.

Old Garrett mine, Charlie Creek. 

Hightower Bald - .................

Washington County --

Diamond Basin -------

Rock Flat gold placer, 

Meadows . 

Paris Canyon, Humming 

Bird mine. 

Little Wood River 

Boise County----------

OQ^f Qy»TTn 1 1 ^

Deadwood Gulch.....................

Pierce, along Rhodes and 

Orofino Creeks.

Latah County .............

"Do TrfVioT* OT*^ A If

Lewiston-- -- ----

T51 d /*»lr<?i. Ano Tnino

Mullan, Hunter--------

Washington County --

T ir»lf (^T'oolr

Indianapolis---- - --

Des Moines County............... 

Keokuk - --- -

Farmington- - -- 

Elliott County----.------

Sandy Hook, Ison Creek-

/^QVinri T^ny1 ]/" f^T'OOV1

Auburn --- 

Gem stone

Quartz^crystal. 

Do. 

Diamond. 

Amethyst. 

Ruby, sapphire. 

Amethyst, aquama - 

rine, golden beryl, 

quartz crystal. 

Amethyst.

Do. 

Fire opal.

Diamond. 

Sapphire .

Jasper.

Azurite . 

Topaz. 

Aquamarine. 

Pyrope, spessartite. 

Common opal. 

Sapphire .

Azurite . 

Common opal. 

Do. 

Almandite, aquamarine. 

Azurite . 

Common; opal, precious opal. 

Azurite . 

Gem corundum, sapphire.

Diamond. 

Amethyst . 

Bronze -colored sapphire. 

Diamond.

Quartz crystal. 

Geodes. 

Chalcedony. 

Geodes.

Jasper. 

Diamond.

Pyrope .

Diamond.

Golden beryl, smoky 

quartz, tourmaline.
GEM STONES OF THE UNITED STATES 237

Table Continued

State and county

Maine Continued 

Androscoggin Continued

Cumberland .......................... .......

TTo 7"» f» r\ r* \r

TCptlflpl^PP

Oxford.....---- 

Sagadahoc - -- 

Maryland: 

Baltimore......................................

Carroll . ..........

Locality

Minot ................ ............... ...........

Mount Apatite, Littlefield Farm.

Poland --- --

Diamond Island, Portland Harbor. 

Mount Desert .......... ....... ......... Winslow ......

Oxford County 

Albany -- - 

Andover .

Bethel ..... . Buckfield ............ ...

French Mountain 

Grafton --»- 

Lovell - - 

Mount Mica, Paris - 

Mount Pleasant.. 

Peru, Speckled Mountain 

Ragged Jack Mountain 

Rumford Falls .. .

Stoneham .... . ...........

Stow.......-.....-.. .. . Phippsbur g .... ....... ....... .......

Topsham -..-». 

Arundel gneiss quarry, 

Gunpowder River. 

Bare Hills . . ... .

Gr.anite ...... 

Between Middleburg and 

Big Pipe Creek. 

Kensington mica mine, 

Burnt Mills.

Gem stone

Smoky quartz. 

Apatite, smoky quartz, 

tourmaline, aquamarine, golden beryl. 

Golden beryl, tourmaline. 

Quartz crystal.

Amazonite . 

Aquamarine. 

Essonite. 

Golden beryl, rose 

quartz crystals, smoky 

quartz, tourmaline. 

Essonite, hiddenite, 

kunzite . 

Aquamarine . 

Milky quartz crystals, 

aquamarine . 

Do. 

Aquamarine. 

Do. 

Aquamarine, tourmaline, morganite. 

Tourmaline . 

Aquamarine . 

Amazonite, rose quartz 

crystals, tourmalinated quartz, sagenite, 

aquamarine, tourmaline, morganite. 

Smoky quartz, amethyst 

Rose quartz crystals, 

aquamarine, tourmaline. 

Aquamarine, rose quartz . 

Golden beryl. 

Chrysoberyl. 

Tourmaline . 

Aquamarine, golden 

beryl, smoky quartz, 

topaz. 

Amethyst. 

Essonite, aquamarine, 

golden beryl. 

Aquamarine, tourmaline, topaz.

Aquamarine.

Moss agate. 

Amethyst. 

Cnrysocolla.

Golden beryl.
238 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

Massachusetts:

Hampshire 

Michigan:

("*Q CO

Kent .----------- 

Minnesota: 

Morrison ---------------

Missouri:

Dent - --- --- -- -

Iron Mountain - -

TDVlpl 1-lQ ....... ___ .. __ .... ___

Montana:

1~*1 Q £1 T* T A H /TO

frl 55 f"*1 OT»

Granite 

Judith Basin-- 

Silver Bow - .........

Locality

Rockport ......................................

Rowley ................................

Northfield ..._........_............. ... 

Blandford....................................

Chester .....................................

Chesterfield ..........................

Royalston - - 

Lake Superior region 

Buchanan - --- 

Keweenaw Peninsula, a, 

Thunder Bay. 

Allouez mine -------

Royalton 

Crawford County - 

Dent County ----------- 

Iron Mountain County- -

Phelps County -

Cable mine .................................

Dry Cottonwood Creek-- 

Nelson Hill, near Blackfoot. 

Philipsburg ..............................

Rock Creek ...............................

Homestake mining district, Butte.

Yogo ................................................

J

Canyon Ferry, Missouri

Eldorado Bar --- - 

Three Mile GulchJrUlC wi CCJ\

East Ridge Foothills - 

Browns Gulch 

Gem stone

Amazonite . 

Jasper. 

Aquamarine, garnet, 

golden beryl. 

Aquamarine, golden 

beryl. 

Jasper. 

Emerald, tourmaline. 

Aquamarine, emerald, 

smoky quartz, tourmaline. 

Aquamarine, golden 

beryl. 

Jasper. 

Aquamarine . 

Aquamarine, golden 

beryl.

Agate . 

Do. 

Diamond. 

Do. 

Rose quartz. 

Amethyst.

Chrysocolla. 

Staurolite.

Azurite . 

Do. 

Smoky quartz. 

Azurite.

Sapphire . 

Moss agate.

Chrysocolla. 

Sapphire . 

Diamond.

Chrysocolla.

Sapphire .

Do.

Amethyst, smoky

quartz. 

Sapphire, ruby.

Sapphire .

Do.

Do.

Smoky quartz,

Garnet, onyx.

Sapphire. 

Chrysocolla. 

Sapphire .
GEM STONES OF THE UNITED STATES 239

Table Continued

State and county

Nebraska: 

 Keith, Scotts Bluff, and 

Sioux. 

Nevada: 

Churchill - - - - -

riark.....

Elko ....................................................

Esmeralda .................................

"p1 1 1 T* Q 1^5)

Humboldt--------------

NVQ

Washoe ----------------

White Pine ....................................

New Hampshire: 

Belknap - -

Par- foil

Coos-----------------

Locality

Keith, Scotts Bluff, and 

Sioux Counties.

Sunnyside district------

Black Canyon, Colorado 

River. 

Bullion district ......................

Crescent......................................

Carlin .........................................

Mountain City----------

T1! ic:r*QY*r^"r*3

Blair Junction---------

P*nal T^alo

Cuprite district -- . Gold Mountain ----------

Millers --------------

Palmetto Canyon 

Silver Peak Mountains . 

Ruby Hill and Eureka 

districts. 

Coyote Springs .......................

Virgin Valley ........... ................

Battle Mountain, 53 miles 

east of Winnemucca. 

Beatty - .................. ................

Belmont ...................................

Cactus Mountain, Butler.

"Dcjhnto TV/Tocja

Tonapah ------ ..........................

Reno------------ - - 

Nightingale district, 

near Lane City.

Gilmanton------ -- - -----

Chatham, South Bald 

Face Mountain.

Mount Kearsarge- ------ 

Hinsdale .....................................

K00H0

Sullivan, Nims mica 

mine.

Walpole------ ..........................

Westmoreland -------

Winchester ----------

Berlin 

Diamond Ledges -- --

Gem stone

Moss agate.

Malachite. 

Almandite.

Chrysocolla,malachite. 

Turquoise. 

Azur ite . 

Gold quartz, turquoise. 

Rose quartz. 

Azurite . 

Citrine, rose quartz. 

Turquoise. 

Do. 

Malachite . 

Citrine. 

Turquoise. 

Citrine. 

Rose quartz.

Azurite .

Agate. 

Agate, precious opal. 

Opal. 

Turquoise.

Agate nodules. 

Petrified wood. 

Turquoise.

Agate . 

Do. 

Black jade, turquoise. 

Turquoise. 

Almandite.

Jasper . 

Beryl, topaz.

Amethyst, rose quartz. 

Indicolite. 

Rose quartz. 

Aquamarine , golden 

beryl. 

Amethyst. 

Indicolite . 

Amethyst. 

Indicolite . 

Amethyst . 

Smoky quartz. 

Jasper. 

Topaz.
240 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

New Hampshire Continued 

Coos Continued

Grafton ................................................

Hillsboro----------.-..--..

T\/Tp T* T* T in d f* \r

Strafford ---------------

Sullivan - - --- ----

New Jersey:

f^Qno A/Tow

l^oopv

Hudson .............................................

"Do o o Q i /"»

New Mexico:

Grant - - -

Mora .......-.---- 

rcio ArriDd ............ 

San Juan ........... ......... ...................

Locality '

White Mountains, Mount 

Washington.

Grafton. ................. ...................

Or ange ...... .........

Warren- -----------

A TYl)'lOT> C:t

Danbury, P. K. Filbert 

Farm.

Oonfoy Ql Y»OT*T*r\T»H

Sullivan County . ..

Acworth, Beryl Mountain.

Springfield .............................

Oor^p TV/To-'CT

Belleville and Bloomfield. 

Hoboken ..................................

Long Branch ... .....-..........

Bound Brook ----------

Lyons Station-----'- -

Franklin Furnace-------

Organ, Torpedo mine-- 

Black Range, Great Republic .mine . 

Burro Mountains, Porterfield mines.

Fort Bayard- ----

Little Hachita MountainsSilver City ....... ..... J

White Signal district 

Anphn ................

Coyote - - - 

t/ 

To Y»i1 1 o ................

Bromide- ---

Navajo and Zuni Reservations .

Gem stone

Rose quartz.

Andradite, azurite. 

Almandite, aquamarine, golden beryl, 

topaz, smoky quartz. 

Almandite, jasper, 

quartz crystal, rutilated quartz. 

Aquamarine. 

Essonite . 

Do. 

Jasper. 

Almandite, golden 

beryl. 

Aquamarine, golden 

beryl. 

Golden beryl. 

Almandite, aquamarine, rose quartz, 

golden beryl. 

Spessartite.

Quartz crystal, jasper. 

Malachite. 

Agate, amethyst, black 

quartz. 

Quartz crystal. 

Amethyst. 

Agate . 

Amethyst geodes. 

Turquoise. 

Amethyst;

Chrysocolla. 

Amethyst.

Chrysocolla, turquoise. 

Opal. 

Turquoise.

Fire opal.

Essonite.

Turquoise. 

Jasper.

Turquoise. 

Agate . 

Azurite, malachite.

Malachite. . Chrysocolla, turquoise.

Azurite, malachite,

amazonite. 

Pyrope .
GEM STONES OF THE UNITED STATES 241

Table Continued

State and county

New Mexico Continued 

San Miguel ....................................

Sandoval

Santa Fe .........................................

Socorro -------------

Tanc;.

"\7js 1 onfi Q

New York: 

Albany -"---- - 

PQCOY

TTp y» If -i yyi o f*

Ontario--»---------»----

r^T*QTirro

Richmond .... ..................................

CJf T QTirpOYlC^O

AA/P c: t f* Vi p c f o T

North Carolina:

A 1 o VQ ~n H o T*

Locality

Tecolote.. ....

Cochiti district ......................

Nacimiento.................................

Santa Fe County ....................

Los Cerillos .............................

Caballos .................................

Oscura Mountains-------

Taos County ----------

Copperton, Zuni Mountains .

Albany County .........................

Essex County .......................... 

Crown Point---- ------

Herkimer County ------

Diamond Hill, SalisburyLittle Falls . 

Middleville ----------

Newport----- -- ---"

T71 c Qov"

Manhattan borough------

Blooming Grove, along 

Hudson River. 

Toddsville - 

Tilly Foster mine, 

Brewster.. 

Staten Island ............................

Greenfield.. .................

PloValT-i

T\/TQ CQOTIQ

Gore Mountain, North 

Creek.

T o Iro (*"io i^Y1 rrQ

Bedford Village ...............

Chappaqua - - ............

Kinkel and Hobby quarries, North Castle.

Alexander County------

Emerald-hiddenite mineHiddenite - .-...

Stony Point-----------

Gem stone

Azurite, malachite. 

Opal. 

Chrysocolla,malachite , 

azurite . 

Sapphire. 

Turquoise. 

Malachite . 

Chrysocolla. 

Pyrope . 

Malachite..

 Heliotrope. 

Almandite . 

Sunstone . 

Quartz crystal, smoky 

quartz. . Quartz crystal. 

Do. 

Do. 

Do. 

Labradorite . 

Aquamarine . 

Smoky quartz. 

Heliotrope, jasper.

Sapphire . 

Grossularite, uvarovite . 

Prase . 

Chrysoberyl. 

Chrysoprase, tourmaline . 

Tourmaline . 

Diamond. 

Tourmaline. 

Almandite .

Quartz crystal, smoky 

quartz. 

Asteriated quartz, golden beryl, rose quartz. 

Sunstone . 

Golden beryl, rose 

quartz .

Pyrope . 

Aquamarine. 

Emerald. 

Rutilated quartz, aquamarine . 

Amethyst, citrine, emerald, golden beryl, 

hiddenite, quartz crystal, tourmalinated 

quartz, smoky quartz.
242 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

North Carolina Continued 

Alexander Continued

AcVif^ .. . ... _ . ___

Avery - - 

Buncombe------- 

Cabarrus ................................. ......

Caldwell- - --

Clay 

Davidson - ----- .... .... .

"C1 y»OV»l/'l 1 T-l

Gaston------ ----- - ....... ..

Granville.........-.......... ......... ....

T-rpripll

«JcU~.&.oUIr

Locality

Phoenix Mountain, Long 

Shoals Creek, Chestnut 

Hill Township.

Linville--- 

AcVlOT7"i11 O

Asheville, Morgan Hill-- 

Burke County---------

BrindletownCreek Ford 

Burkemont, South Mountains . 

Morganton, Laurel 

Creek. 

South Mountains, Joel 

Walker prospect. 

Concord, Harrisburg 

Caldwell County-------

Catawba County 

Cullakeenee mine, Buck 

Creek. 

Elf on Shooting Creek 

(~*d CQ T»

ICings Mountain -------- 

Shelby, Hollybush prospect.

Tavrv

Portis gold mine- - -- -

Gaston County 

Granville County 

Jackson County- - 

Grimshawe mine, Montvale. 

Mason Branch valley, 

near Franklin. 

R. E. Brown prospect 

Sapphire and White Water mine.

Gem stone

Citrine, smoky 

quartz . 

Rose quartz. 

Quartz crystal.

Almandite . 

Chalcedony. 

Aquamarine. 

Chrysoprase. 

Citrine, almandite, 

quartz crystal, rutilated quartz, smoky 

quartz. 

Diamond. 

Gem beryl.

Pyrope. 

Aquamarine.

Chalcedony, opal. 

Almandite, aquamarine . 

Almandite , c itr ine , 

emerald, rutilated 

quartz, quartz crystal, rose quartz, 

smoky quartz. 

Emerald, ruby matrix. 

Hyalite opal, ruby 

matrix, sapphire. 

Rutilated quartz. 

Diamond. 

Emerald.

Do. 

Amethyst. 

Do. 

Diamond. 

Aquamarine. 

Jasper. 

Amethyst. 

Green tourmaline. 

Amethyst, opal, rose 

quartz, rutilated 

quartz. 

Almandite, rutilated 

quartz. 

Gem corundum, aquamarine. 

Rhodolite.

Aquamarine. 

Sapphire .
GEM STONES OF THE UNITED STATES 243

Table Continued

State and county

North Carolina Continued 

Lincoln. . .

McDowell ---------- .

Macon -. .

Madison -- 

Mecklenburg- . -

Mitchell - ----- 

Moore -

Orange 

"DoT*Q/^^

Randolph 

Rowan-- --»»-»- .

Stokes....... .... ........... .. . Surry ....... .. ........ ........ ...........

Wake .-. 

"V"jinr*AT7

Ohio:

Oklahoma: 

McCurtain . ...

Oregon:

"Do l/-rty»

Locality

Cottage Home 

Line olnton-- ---------

McDowell County 

Dysortville, headwaters 

of Muddy Creek. 

Corundum Hill mine, 

Cullajasa. 

Ellijay mine, E Hi jay 

Creek. 

Franklin area, Co wee 

Valley. 

Littlefield mine, Tessentee Creek.

Madison CountyT?opHc; |^v»oolf

Caldwell ........ . .... ....

Todd ' s Branch

Mitchell County ----- -- -

Hawk mine------ -------

Crabtree Mountain, Emerald Matrix mine. 

Medlock Mountain, Bakersville.

SriTiiPP PinP

Orange County ....... ....

Person County . ......

Randolph County -----

Gold Hill 

J. B. Twitty gold placer 

mine. 

Dan River 

Elkin and White PlainsWake County 

Raleigh.. . 

Yancey County 

Burnsville, Ray mica 

mine.

Milford -------»------

m OT/PT* r^7»polr

Wichita Mountains 

Gem stone

Diamond. 

Amethyst. 

Do. 

Do. 

Pyrope. 

Diamond.

Hyalite opal, emerald, 

sapphire. 

Gem corundum.

Ruby, rhodolite.

Amethyst, aquamarine, 

golden beryl. 

Chrysoprase. 

Opal. 

Aquamarine, jasper. 

Chalcedony. 

Diamond. 

Almandite . 

Aquamarine, emerald, 

essonite, quartz crystal, oligoclase. 

Moonstone. 

Emerald.

Suns tone.

Emerald, corundum, 

garnet, golden beryl, 

zircon, moonstone, 

sunstone, kunzite. 

Aquamarine, emerald. 

Jasper. 

Chalcedony. 

Jasper. 

Rutilated quartz. 

Sunstone . 

Diamond.

Rose quartz. 

Quartz crystal. 

Jasper. 

Amethyst. 

Do. 

Almandite. 

Amazonite, aquamarine.

Diamond.

Quartz crystal. 

Rutilated quartz.

Malachite, precious opal, rhodolite, almandite.
244 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

Oregon Continued

OX UUiv 

OLLI i y

Harney--- - 

Josephine---------------

Wallowa 

Pennsylvania:

T3p ylrc

"Rnp lr^

Carbon-----------..-.-.---

f"1 Vi o c: i" o T*

Locality

Nehalem River ---.-----

JDCI1U dl CcL . Cedar Springs Mountain.

Nickel Mountain 

Harney County -------- 

Waldo and Galice districts.

Newport Beach 

Toledo 

Salmon River and Cedar 

Creek, near Toledo.

Vcj r* Vto f c

Opal Butte- - --- 

Joseph, on Lower Inmaha River.

Warm Springs Indian 

Reservation.

Fritz Island, near Reading.

"Ppa cfpT»\7il 1 p.. _._. ,. .

Hauto ......... . .... . ......

Chester County 

East Bradford Township.

Northrup .......... ....... 

Nottingham Township 

Phoenixville -

Pocopson Township 

Sadsbury Township - 

Unionville -

Avondale ,Leiper. quarryBrandywine Summit- -

Middletown - -- - 

Lancaster County- - 

Gem stone

Heliotrope, iris agate. 

Carnelian. 

Azurite, chrysocolla. 

Jasper . 

Opal. 

Diamond. 

Agate nodules. 

Azurite, malachite.

Chrysoprase . 

Sapphire . 

Azurite, chrysocolla, 

malachite . 

Heliotrope. 

Agate . 

Carnelian.

Sagenite . 

Opal. 

Prase .

Iris agate, jasper. 

Heliotrope. 

Agate .

Azurite, malachite, 

jasper. 

Sunstone . 

Quartz crystal. 

Jasper. 

Almandite, chrysoprase, jasper, moonstone, tourmaline. 

Gem beryl. 

Amethyst.

Malachite . 

Gem beryl. 

Sunstone . 

Azurite-. 

Amethyst. 

Do. 

Gem beryl. 

Jasper, moonstone. 

Almandite, aquamarine, essonite, green 

beryl . 

Copper minerals. 

Rutilated quartz. 

Beryl, garnet. 

Amazonite, amethyst,

sunstone,

Amazonite . 

Amethyst. 

Jasper, rutilated 

quartz, uvarovite.
GEM STONES OF THE UNITED STATES 245

Table - C ontinue d

State and county

Pennsylvania Continued 

Lancaster Continued

Lehigh ..............................................

Perrv

Philadelphia ............. ...................

Rhode Island: 

Providence 

South Carolina:

Ancierson "

South Dakota: 

Custer, Pennington 

Minnehaha ....................................

Pennington........ .....................

Tennessee: 

Hamblen .............. ....... ........... . .

Monroe ............................ ................

Pnllr

Roane ...............................................

Texas:

Locality

Wood's Chromite mineCornwall .. - ---

Lehigh County -------

Bethlehem ......................... ..

Audubon .......................................

"DoY*k"i fMYion Tn i no

"DVll 1 Q/^ol T"\Vll Q CJ T*OQ

Sumneyto wn ----------

Stroudsburg 

Philadelphia County 

Falls of Schuylkill 

"Fo i T*TYI Anr"it 'DoT*!/'

Shawmont - - 

Calumet Hill quarry, 

Cumberland area. 

Diamond Hill, Cumberland Hill.

Anderson, J. N. S. McConhell property. 

Bowen River - 

Black Hills districtElephant Gulch .......................

Harney Peak ............................

Scott Rose quartz mine, 

Custer . 

Sioux Falls ................................

Russell ville ..........................

Monroe County 

Koko Creek, Tellico 

River . 

Ducktown -- 

Clinch River, near Union 

Crossroads.

T nHyoll Plat (~*raalr

San Antonio, Reese 

River.

A/To T*f o _ A 1 1^1 no

Byrd Ranch, Alpine----

HcUcy x~^t;cli\. "" "*

Gem stone

Uvarovite. 

Azurite, malachite. 

Andradite, malachite. 

Jasper, prase. 

Azurite, smoky quartz. 

Azurite, malachite. 

Aquamarine . 

Azurite . 

Quartz crystal. 

Malachite . 

Smoky quartz, spessartite. 

Amethyst. 

Beryl, spessartite. 

Do. 

Do. 

Do. 

Do.

Jasper, rutilated 

quartz. 

Agate, milky quartz, 

quartz crystal.

Amethyst. 

Aquamarine , green 

beryl, amethyst. 

Emerald, sapphire. 

Diamond.

Azurite, aquamarine, 

golden beryl, hiddenite, petrified wood, 

rose quartz. 

Pyrope, almandite. 

Rose quartz. 

Do.

Jasper . 

Geodes.

Quartz crystal. 

Malachite . 

Diamond.

Azurite, malachite. 

Diamond.

Do. .. 

Prase.

Agate . 

Labradorite. 

Fire opal. 

Amethyst.
246 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

Texas Continued

"C1 ! TDacri

Fayette ...............................................

Hidalgo 

Llano 

"Do T»b-p-y»

San Patricio . . .

Walkpr

Webb - ---- --------

Utah:

"RaQTTQT*

Box Elder 

OQ r* Vio

Davis-- - 

Grand--- 

Iron - 

Juab 

Millard--------- - 

Piute 

Salt Lake .

San Juan.-- 

Tnnalo lUUclc ............ 

Uintah - 

Utah 

Locality

Fayette County 

Sullivan City -

Grit - - - 

5-\llwpY* Opak" . __ _ ...

San Patricio CountyHuntsville --------------

Zapata County- - 

Beaver CountyCopper Gulch, Star and 

Frisco districts.

Milford . - 

Copper Mountain mine, 

Lucin district. 

Newfoundland 

Promontory Point 

Silver Island 

T Q ID! at-a

Castle Valley district 

San Rafael Swell 

Summerville district -

Grand County 

Gold Springs 

Thomas Mountains

Tintic-- . -- -

Copper Mountain mineT^PPT (^T'Oolr

Big and Little Cottonwood. 

Old Jordan mine, Bingham. 

Navajo Reservation 

T o Qol r^icfyi^*^

Ball mine, Sevier Canyon. Clifton district-------

Ibapah Mountain - - 

Simpson Springs 

AmericanFork Canyon -

Gem stone

Turquoise. 

Amethyst. 

Quartz crystal. 

Jasper. 

Agate, amethyst, opaJ, 

rose quartz, topaz. 

Topaz. 

Amazon! te, topaz. 

Topaz. 

Prase . 

Agate. 

Diamond. 

Agate, jasper. 

Do.

Azurite, malachite. 

Garnet.

Chrysocolla. 

Opal. 

Chrysocolla.

Malachite. 

Do. 

Do. 

Do. 

Azurite, malachite. 

Do. 

Do. 

Do. 

Agate. 

Azurite, malachite. 

Azurite . 

Agate . 

Garnet. 

Garnet, topaz. 

Azurite, Chrysocolla,

malachite. 

Labradorite. 

Azurite , malachite . 

Garnet. 

Malachite . 

Azurite, garnet, malachite . 

Opal.

Pyrope, spessartite. 

Azurite, malachite. 

Do.

Azurite, garnet, malachite . 

 Aquamarine, 

Morganite. 

Azurite, malachite. 

Garnet.
GEM STONES OF THE UNITED STATES 247

Table C ontinued

State and county

Utah Continued 

Washington...................................

Weber ..............................................

Vermont: 

Orange.......... ......... ...................- 

Washington ..................................

Windsor ..........................................

Virginia:

A yv°i ol 1 3

Campbell........................................

Charlotte......................................

Chesterfield................................

Fairfax...........................................

Hanover.........................................

Henry..............................................

Louisa.............................................

Madison.........................................

Mecklenburg...............................

.Nelson............................ .................

Page . ..

Patrick. .

Rockbridge.- 

Rockingham--- ----- ---

Warren ............................................

Washington:

Phplan

PI ark

' Ferry ---------------

To'f"foY*C!('"i7'i i

King .. .. .....................

Lincoln ----------------

Snohomish -------------

Walla Walla .................................

Locality

Dixie and Silver Reef........

Ogden Boilermaker mine

Copper mines at Corinth, 

Copper fie Id, South 

Str afford. 

Waterbury .......... ......

South Royalton - - ............

Amelia Court House 

Amherst County . ......

Lowesville ................................

Fancy Hill.................................

Campbell County .................

Brookneal ..................................

Charlotte Court House..... 

Manchester

Fairfax ..... . .... . .......................

Hewlett .

Henry County. .................... .

Trevilians ......

Fishers Gap.............................

Pontiac mine .........................

Nelson County ........................

Patrick County ......................

TT*I QVi (~*v*&&\r

High Knob, Elkton - 

Bentonville ................... .............

Front Royal ..............................

Bell Mountain mine - 

Republic mining district -

"Diiofl AT* Oyoolr

Denny Mountain--------

Newport -- - ------

Old Siegmund RanchSedro Woolley .. 

Monte Cristo district- -

Whelan locality near 

Pullman. 

Moses locality, Clar kstonGem stone

Azurite. 

Garnet, malachite. 

Azurite, malachite. 

Do. 

Garnet.

Malachite .

Rutilated quartz. 

Quartz crystal.

Amazonite, beryl, amethyst, rutilated quartz, 

spessartite, moonstone, sunstone, topaz, 

tourmaline . 

Rutilated quartz. 

Amethyst. 

Do. 

Turquoise crystals. 

Amethyst. 

Do. 

Diamond. 

Gem quartz. 

Moonstone, sunstone. 

Staurolite. 

Amethyst. 

Azurite. 

Do. 

Amethyst. 

Azurite . 

Staurolite . 

Amethyst. 

Beryl. 

Azurite . 

Do. 

Azurite, chrysocolla.

Quartz crystal. 

Gem quartz. 

Gold. 

Gem quartz. 

Do. 

Do.. 

Precious opal. 

Amethyst. 

Amethystine quartz. 

Nephrite . 

Amethyst. 

Malachite. 

Essonite. 

Opal. 

Precious opal.

Do.
248 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table Continued

State and county

West Virginia:

Wisconsin:

7~"iQ 'HO

PsrcG

Washington.--------"---...

"\I 7o 1 1 \r& O Vl Q

Wood ..- --.-- 

Wyoming: 

Albany........................................... «/

Carbon.................... .........................

Crook....... ................. .................

Fremont .... ........ ........ ........... .............

Goshen ....... . ..... ,..

Johnson ........ .- ---

Laramie- -- - --

Natrona'--- ----------

TDQT»1/-

"Dlofto

^\TX7Aoi"TI?Q tOT*

Locality

Saukville .-...-... ........ .......

Kohlsville - ................--..

Eagle .........:. ........ . .

Grand Rapids

Holmes, Grand Encampment district.

Lander . .... ....... ...... 

Long Creek ...............................

Sage Hen Creek 

Bighorn Mountains- 

^1 Q rra TTo n (~* T» o o \f

Kirwin -. -.-.-.

Wilde and Deercorn 

mine, Guernsey. 

Eden Valley ........ 

Yellowstone National 

Park.

Gem stone

Diamond.

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Rose quartz.

Azurite, malachite.

Moss agate, malachite. 

Azurite. 

Nephrite . 

Moss agate. 

Ruby. 

Moss agate. 

Azurite, garnet, chrysocolla, malachite. 

Azurite. 

Heliotrope . 

Moss agate. 

Malachite . 

Moss agate.

Petrified wood. 

Amethyst, agate, petrified wood.

OTHER GEM STONES IN THE UNITED STATES

State County Locality

AMBER 

[Fossil resin]

Massachusetts 

New Jersey ............. ..................:............ Camden...... ...... .......... ...................

Salem.... .........................................

Mercer... .. ... ....

......do.......- ...... .........................

Gay Head, Martha's

Vineyard. 

Nantucket.

Camden.

Harrisonville.

Trenton.

AXINITE 

[Al, Ca, Fe, Mn hydrous borosilicate; honey yellow]

California

NPW Jpf^pv

Pennsylvania ...., ........ ........ .

San Diego ...... .... ...

CSiOCQ-y

Northampton ............... .... ..

Bonsall.

Bath.

Franklin Furnace .
GEM STONES OF THE UNITED STATES 249

Table Continued

State' County Locality

BENITOITE 

[Ba, Ti silicate; blue]

California. San Benito-.. Headwaters of the San 

Benito River.______

BOWENITE 

g;unusually translucent, apple-green or greenish-white serpentine]

Rhode Island.............:.......................... Providence.. Smithfield.

CALIFORNITE .

[Basic Ca, Al silicate; olive green to grass green, brown idocrase. Called 

vesuvianite in older textbooks]

California......................................:....... Riverside.................................... Crestmore.

Siskiyo'u... . ... ........... Indian Creek.

Tulare........................................... Exeter.

Plumas......................................... Clio.

Butte..........................................:... County.

Fresno.......................................... Do.

Maine....................................................... Cumberland.............................. Raymond.

Sagadahoc................................... Phippsburg.

York.......................................... Sanford and Cornish.

AndroSeoggin.......................... Robinson Mountain,

Lewiston. 

New Hampshire................................ Grafton......................................... Warren.

New York.............................................. Essex........................................... Olmstedville._______

CATLINITE 

[ Compact red clay mineral]

Arizona................................................... Yavapai......................................... Jerome.

^Minnesota.............................................. Pipestone .................................. County.___________

CHIASTOLITE 

[ Al2Si05 variety of andalusite with cross in transverse section]

California.............................................. Madera......................................... Daulton.

Mariposa.... ............................. Moores Hill.

Riverside. .............................. Coahuila.

Massachusetts. ............................. Worcester..................-.-:..-.... George Hill, Lancas-

________________________________ ter, Sterling._____

CHLORASTROLITE 

____[Translucent to opaque green variety of prehnite or thomsonite]___

Michigan............................................................................................................ Isle Royal and Green

Stone Island in Lake 

Superior. 

Keeweenaw................................ Mandan and Porcupine

Mountain.

Minnesota ....................................... Cook............................................... Grand Marais.

DANBURITE

,; wine yellow]

Connecticut........................................... Fairf ield..................................... Danbury.

New York ............................................. st. Lawrence--------- Russell.
250 CONTRIBUTIONS TO ECONOMIC GEOLOGY

Table C ontinued

State County Locality

ELAEOLITE 

[NaAlSiO4; flesh, cinnamon, yellow brown, related to nephelite]

Arkansas. Garland........................................ [Magnet Cove.

HYACINTH (GEM ZIRCON) 

ZrSiO4 ; orange, reddish, brownish]

Colorado.................................................... El Paso and Jellee...............Pikes Peak region.

Maine.......................................................... Kennebec..................................... Litchf ield.

Massachusetts...................................... Hampshire-....-....--..-..-.... Chesterfield.

Texas.......................................................... Llano.............................................: County.________

PERIDOT 

[ Mg, Fe silicate; dark yellow green]___________

Arizona...................................................... Gila..._............................................ Talklai,

Apache.......................................... Fort Defiance, Ziltsusayan Butte, Gan- 

______ada.____________

PHENACITE 

__ _____ ________[Be2SiO4 ; colorless]____________ ____

Colorado............................................................................................................... Mount Antero, Pikes

Peak, Crystal Park, 

Crystal Peak. 

El Paso............ ....................... Topaz Butte, near

Florissant. 

Kentucky....... ...................................... Elliott ............................................ County.

Maine...................................................................................................................... Bald Face Mountain,

Stoneham. 

Oxford.......................................... Greenwood.

New Hampshire.................................... Carroll .........:............. .................. North Chatham.

North Carolina................................... Jackson........... ............ ............ Webster and Balsam

___________________ ___________;_____ Gap.____________

PREHNITE 

_______________[ H2Ca3Alg(SiO4 )3; light green] _____________ ,

Connecticut ........................................ Hartford ......_.............................. Farmington.

Massachusetts-.... . .. Middlesex Somerville.

Michigan- . --- --- Keweenaw ................................ Isle Royale.

New Jersey. ...................................... Middlesex .- --- Bergen Hill.

Passaic . .......... Great Notch and Paterson. 

 Pennsylvania------------- Delaware ............ ............. French Creek mine.

RHODONITE

[ MnSiO3; red or streaked with black MnO, pink, fleshy, when occurring with 

_____________________rhodochrosite]_____ _______________

California ...................................... Piumas..................:.-................... Taylorsville, Indian

Valley. 

SiskiyOU........ . .. Happy Camp.

Maine ............................ ........- . Hancock....................................... Blue Hill, Osgood

Farm. 

Massachusetts....................................... Hampshire................................. Cummington.

Montana. .......................................... Silver Bow................................. Butte.

New Jersey.............................................. Sussex...........................- - Mine Hill, Franklin

Furnace. 

Morris.. .......................... Dover.

Oregon,.............................. .................... Josephine and Jackson...... Evans Creek and Cave

__________________________________ Creek.________
GEM STONES OF THE UNITED STATES 251

Table Continued

State County Locality

SPINEL 

[MgAl204 ; red, blue, green, yellow, brown, black]

New Jersey......................................... Hunterdon................................... Bryam.

Sussex........................................... Andover.

New York ............................................ Orange.........;................................. Amity.

North Carolina................................ Macon............................................ Culsagee mines, near

___________:_____Franklin._______

THOMSpNITE 

[(Ca, Na21; Al2Si^Oe- 2-|H20 occurs with zeolites, white and reddish brown]

Arkansas............................................................................................................. Ozark Mountains.

-Colorado................................................ Jefferson.................................... Table Mountain,Golden.

Michigan............................................................................................................ Isle Royale, Lake Superior region. 

Alger.............................................. County.

Minnesota ............................................ Cook................................................ Thomsonite Beach,

near Grand Marais.

New Jersey.......................................... Passaic......................................... West Paterson.

New York ............................................. Westchester.............................. Peekskill.

Oregon................................................... Columbia..................................... Goble.___________

TITANITE 

[Ca, Ti silicate; brown, green, honey yellow]________

Arkansas.............................................. Garland......................................... Magnet Cove.

New Jersey ........................................ Sussex........................................... Franklin.

New York.............................................. Lewis............................................. Diana, Natural Bridge.

St. Lawrence .......................... County.

Orange......................................... Do.

Putnam......................................... Do.__________

VARISCITE

[ A1P04- 2HaO; a matrix stone of dark to light green with white phosphatic 

material, chert, chalcedony]___________

Arizona ................................................. Maricopa........................ ... Alamo Mountain, near

Aguila. 

Arkansas.............................................. Garland........................................ County.

Nevada............................................ Esmeralda ........................... Coaldale and Columbus.

Nye---- .................................. Utahlite at Manhattan.

Utah.......................................................... Boxelder...................................... Lucih.

Tooele............................................ Mercer, Stockton, and

Stansbury Mountains.

Utah................................................ Fairfield.

Washington................................ Oquirrh Mountains.

WILLEMITE

[ Zn2SiO4; white, yellow, green, apple green, flesh red, grayish white, yellowish brown]____________________

New Jersey.......................................... Sussex.......................................... Franklin at Mine Hill

and Sterling Hill. 

New Mexico......................................... Socorro......................................... Merritt mine.

Utah..............-.............. ....................... Beaver......................................... Star district._____

WILLIAMSITE

[Massive, fibrous, foliated, various colors, varietyof serpentine, rich blackish oil green]

Maryland............................................... Montgomery............................. Bare Hills.

Pennsylvania....................................... Northampton............................. Easton.

Lancaster.................................... Texas.

Chester......................................... West Chester.
CONTRIBUTIONS TO ECONOMIC GEOLOGY

SELECTED BIBLIOGRAPHY

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Henry, D. J., 1948, California gem trails: Portland, Oreg., Mineralogist

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HI., Bennett Co.

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OC.O 

GEM STONES OF THE UNITED STATES *°

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U. S. GOVERNMENT PRINTING OFFICE : 1957 O 41 2673