THn AUERIcAN MtxERALocIST
JOURNAL OF THE MINERALOGICAL

Vol. 36

SOCIETY OF AMERICAJANUARY-FEBRUARY, 1951

Nos. I and 2

THE URANIUM MINERALS FROM THE HILLSIDE
MINE, YAVAPAI COUNTY, ARIZONA*
JoseeuM. Axernou, FnaNr S. Gnruaror,CuAnr,esMrtToN,
awn K. J. Munere
U. S. Geological
Sur'uey,Washington,D. C.
Assrnact
Coating gypsum on the 300-foot level oI the Hillside Mine, Yavapai County, Lrizona,
was a small deposit in which were found several hitherto unknown uranium minerals, together with schroeckingerite, which had been previously known only from Wyoming andCzechoslovakia. The new speciesare named andersonite, swartzite, and bayleyite; they are,respectively, hydrous uranyl carbonates of sodium and calcium, of calcium and magnesium,and of magnesium, all of general formula XrUOz(COs)s zIIrO, where X4 represents respectively, Na2Ca, CaMg, and Mgz, and z, respectively,6, 12, and 18' With these minerals occur two other new substances, naturally occurring dehydration products of swartzite and bayleyite, respectively, whose definitive properties are not well enough known topropose them as valid species. Andersonite, swartzite, and bayleyite, previously unknown
either as minerals or synthetic compounds, have been synthesized Analyses, opticai data,
r-ray patterns, and crystallographic data of these new speciesare given, with r-ray patternsof the dehydration products above mentioned. Schroeckingerite also has been analyzed
and its formula found to difier from that given in the older accounts in the literature; ouranalysis agrees closely with that of the Wyoming schroeckingerite recently reported by
Jaffe, Sherwood, and Peterson.l The various uranium carbonate minerals recorded in theand schroeckingerite
literature are briefly considered. of them, liebigite (:uranothallite)
are weli established. Voglite is almost certainly valid; randite certainly, and rutherfordine
probably, are to be discredited; sharpite may be valid; the status of studtite and diderichite
is very doubtful.
LocatroN

AND GEoLoGTcAL

SETTTNG

Dr. Charles A. Anderson, geologist of the U. S. Geological Survey,
who first observedand collectedthe material in which the uranium minerals here described occur, has given us the following information concerning the Hillside Mine. It is located in Yavapai County, west-central
Arizona,3] miles north of Bagdad, and 43 miles by airline from Prescott.
The mine produces gold, silver, lead, and zinc from a vein several feet
* Published by permission of the Director, U. S. Geological Survey.
1 References are listed by numbers at end of this paper'

2

J. M. AXELROD,F. S. GRIMALDI, C. MILTON, R. J, MURATA

thick. Faulting, post- and pre-mineralization, has occurred. Sulf;despresentin the vein includepyrite, arsenopyrite,galena,sphalerite,chalcopyrite, tetrahedrite, and argentite; minerals of the oxidation zone include silver, cerargyrite, cerussite, anglesite, smithsonite, and hemimorphite. The country rock is pre-Cambrian mica-schist,intruded by
pre-Cambrian granite. The age of the mineralization is thought to be
Cretaceousor early Tertiary because,in the lower levels of the rnine,
the vein is reported to cut porphyry dikes, as at Bagdad.
Uranium minerals were found in only one place, as a coating aboutt inch thick on gypsum, in the oxidized zone, ancl about forty feetabove the water level. The sourceof the uranium is not known; it may berelated to small aplite-pegmatitedikes in the pre-Cambrian schist thatare associatedwith the granite, or it may have been depositedwith theore vein. fn any case) the uranium carbonate minerals are clearly of
secondaryorigin, and were depositedon the walls of the drift. Subsequent
mining operations have completely obliterated the occurrenceof thesecondaryuranium minerals.
No pubiished data appear to exist on the Hillside Mine, and a recent
publication listing the known minerals of Arizona doesnot mention any
uranium minerals as occurring in Arizona.2
Very recently a specimen of uranium-bearing ore from the 400/ levelhas been receivedby us, and is now under investigation.An altogether
difierent uranium mineralogy is present, the minerals johannite (hydrous
copper uranium sulfate), pitchblende,and a probably new zinc uranium
sulfate having been recognizedthus far. A further account of theseminerals will appear in a subsequentissue oI the American Mineralogist.
AppBeneNcBor SpocrunNs
Adhering to the micaceous schist are scattered green rosettes of
schroeckingerite, r,r'ith sulfur-yellow bayleyite. Overlying this schist isa layer of snow-whitegranular gypsum containing small clustersof vivid
green swartzite. Coating gypsum is a mass of yellow bayleyite, most of
it now altered to a pale-yellow powder. The rare andersonite is easil.n.overlooked; superficially, it resemblesswartzite, but when the two minerals are seen together, the distinctive characters are apparent. fn general, the several uranium minerals are intergrown with one another andwith the gypsum and schist minerals; only schroeckingeritecan be easily
obtained in relatively large masses (about a pin-head in size) of a fairdegree of purity.
fn the mine, bayleyite crystals are sharp and well faceted. In thedrier atmosphere of Washington, they soon become duil, losing their
Iuster and finally disintegrate to a yellow powder. Sr,vartzitebehaves

I]RANTUM MINERALSFROM THE HILLSIDE

MINES

similarly to a lesserextentlandersoniteis stable. The stability is inverseto the degreeof hydration.
Typical crystals of swartzite and andersopiteare illustrated in Figs.
1 and 2. No natural bayleyite was available for the reasonabove stated.
However, synthetic bayleyite (Figs. 3a and 3b) is illustrated.
MBruon oB SrUDY
The study of the minerals from the Hillside Mine involved specialdifficulties, and at first sight it seernedalmost impossible to separate thecomponentsof the specimens.However, the separationwas made; andin order that other workers, who may encounter material of like naturein the future, may not be unduly discouraged in undertaking similar
investigations,our methods of separation, identification, and analysis
are presented in more detail than they would otherwise be'
The individual mineral crystals are very small, usually almost microscopic; the largest seldom exceed a millimeter in length, except
schroeckingerite, which occurs in fairly pure rosette-like aggregates offlat plates a few tenths of a millimeter in diameter. Moreover, the various
minerals occur more or less mixed, surrounded by and intergrown withthe minerals of the mica schist and with gypsum. To obtian reasonably
pure material for study it was therefore necessaryto crush-not grindthe aggregate,to sift out the dust and coarseparticles, and to pick out
with a needle under a binocular microscope, particle by particle, theseveral samples to be analyzed-a tedious process,but the only course
feasible. At first, before becoming familiar with the varied habit of theindividual minerals, and their rather subtle variations in shadesof yellow
and green, it was also necessary to check the hand-picking frequently
by examination under ultra-violet light making use of the characteristic
fluorescence(seebelow) of the several species.After a suitable quantityof material had been thus obtained, a further selectionfrom the pickedmaterial was made of the clearest possible crystals, which were spectrographically analyzed,.The data thus obtained were invaluable in planningthe quantitative analysis, for, becauseof the small sample available formany determinations, modifications of customary methods had to bedevised. Furthermore, this pilot spectrographic analysis on the purest
possiblematerial indicated which of the minor constituents in the quantitatively analyzedsample were present as contaminants and not as essential constituents of the mineral. Later, synthesisof the minerals from C.P.
chemicals checked the conclusions drawn from the spectrographicand quantitative analyses. At the same time that the spectrographic
study was in progress, the individuality of the analyzed materials wasestablished by their x-ray diffraction patterns.

J. M. AXELROD, F. S. GRIMALDI,

C. MILTON, K. T. MURATA

Pnvsrcat aNl Cnnurcar Dar.q,
The physical data are given in Table 1 and the chemical data in
Table 2.
Fluorescence,oplics and,other physical properlies
The fluorescenceof the minerals was examined under two kinds ofmercury vapor lamps, one providing "short ultraviolet" radiation(Mineralight, model V-41) and the other, "long ultraviolet" radiation(Hanovia Inspectolight). Spectrogramsof the radiation emitted by theselamps have already been published.3 The relative brightness and colorof the fluorescenceof each mineral were the same under both lamps.
Tesm 1. Orrrcar,arn Psysrcal Dere oNAwornsowrrn,
Swanrznn,Bavr,ovrm,
Ann DrnlonerroN
Andenonite

1
color (daylight)
habit
symmetry
extinctiou
srgn
2V (calc )density (measured)(calc )
solubility in water
fluorescence
formula

Pnooucrs
Swartzite

Bayleyite

1.520 (o) colorless
1 540 (c) pale yellow

1.465 colorless
1.51yellow
1 .540 yellow

bright yellow-green
pseudo-cubic
rhombohedral

SIeen
prismatic
mouoclinic

I .455 pinkish?
1.490 pale yellow
1 500 pale yellow
yellowprismatic
nonoclinic
c :a : 1 5 "

(+)

(-)
40'

2.8
2.86
easy
bright whitish-green
NarCaUOr(COr)r' 6HzO

t.J

2.32
easy
bright yellowish-green
CaMgUOz(COg)r 12HzO
Dehydration product

Dehydration productwhitish dull-yellow
pseudomorphousafter
swartzite
weak, color uncertain

1 502
1.551
whitishpseudomorphousafter
bayleyitemoderate whitish-green

"l
color

habit
fluorescence

(-)

30"
2.05
2.06
easy
weak, color uncertain
Mg,UOr(CO.),' 18HzO

The fluorescent colors observed were greens and yellows, typical of
secondary uranium minerals. As is well known, this fluorescenceis dueto the uranyl ion, and consists of five or more discrete bands of wave
lengths distributed throughout the visible spectrum. The wave length
ranges and relative intensities of these bands vary slightly from mineral
to mineral, resulting in a range of color of fluorescencebetween green andyellow. A thorough study of the fluorescenceof secondaryuranium minerals, therefore, requires precise spectrographic measurements.This study
was not possible with the minerals described in this paper becauseof thesmall amounts of pure samples available.
In lieu of a spectrographic study, the fluorescence of the different

URANIUMMINESMINERALS FROM THE HILLSIDE
Taslr 2. ANlrvrrcar- Dara(eNn svl{runrrc AXOnnSOXrre)ANer-ysosor unaNruu MrNrnar,s r,noMARIZON.q
Andersonlte (4)
Mgo
CaO
Na'O
KoO
UOr
Total HzOco!
SOr
F
Acid insol , IgnitedTotal

0.s+0.1(6)8.9+0 5
9 . 3 1 0 .5
43.4t 1 5
1 6 . 7( c )19.6105
1.6+03Synthetic
Anoersomre

Bayleyite (d)Swartzite880
9 .6 1
44.27
16.50
20.61

30.80
35 19
1 4 .6 0
4.43

8.97
2 75
.19
.09
32 +2
36.60
15 36
3 .9 599.74

100.78

903
342

5.24
840
.25
.47
37 19
29.31
17.16
1.98
.30

100.0

100.3099.79

CaMgUOr(COr)r'12HzO
NaeCaUO,(COr),'6H,O
Formula2.3
2 8
Sp. Gr. (determined)
2 '32
2.86
(calculated)
F. S. Grimaldi
F S Grimaldi Marie Eiland
Analysl,Mg'UO'(CO)r'18H'O

2.05
2.06

2.06
r . 5. Gnmarql(o) Only 3 8 ng. of andersonite was available for the complete analysis'(6) Spectrographically by K. J. Murata'(r) By difierence.
(d) The two analyses were made on separate sanples.

Trsr;x,2 (continued)("DAKErrEt')
ANer,vsnsor ScERoEcKTNGERTTE
Arizona

Wstoming

Joachinsthal

1 8 .1 4
3.63

18 31

19.1
nd

3 1- 4 4
2 0 .1 5
t+.20
9.17
2.15

30.27
1 9 .9 5
13.71
9 .6 1

32.4
20.2
nd.
9.1

1 _0 5

4

W yoming
Si0z.95
R2Q 08

HrO
CO,
SOr
F
Insol.

0.63
1 8- 4 4
3.19
.23
31.28
20.20
14.67
9.24
209
1 .5 3

O:F

1 0 1 .5 0
.88

99.91
.90

100.62

99.01

Meo
CaO
NarO
K,O

uo,

Sp. Gr.
AnalystF. S. Grimaldi

A. M. Sherwoodr

100.22 (Sic)

F Gonyera

R. Novdcekr

1,1,5 See references at end of paper,

minerals was characterized visually according to the following scheme.
Two readily available minerals, schroeckingerite and autunite, wereselectedas standards for comparison of fluorescentcolols. The fluorescent6r. M. AXELROD,F. S. GRIMALDI, C. MILTON, R. J. MURATA

color of schroeckingerite under the Mineralight lamp was designatedbright uhitish-green; that of autunite, bright greenish-yeilow.The fluorescent colors of the minerals studied were close to one or the other, but
one (that of swartzite) was definitely intermediate. This was called
yel,lowishgreen. This three-step classification, though rather crude, wasfound adequate for the purpose, and it has the important advantagethat the colors are defined in terms of standards that can be reproduced
easil.yby other investigators. The results of our observationsare includedin Table 1.
The colors of the natural and synthetic andersonites are distinctly
difierent, the former being bright yellow-green and the latter greenish
yellow; and likewise the fluorescencedifiers, that of natural andersonite
being whitish green and that of the synthetic compound yellow-green
and weaker. whether or not this variation is to be ascribed to the 0.s/6
Mgo found in the natural andersonite is not known. The relation ofgreen and yellow color in the uranium compounds to cation or othervariables is an interesting question.
Methods of analysis
The weight of each mineral availabre for chemical analysis was:andersonite3.8 mg., swartzite0.25g., bayleyite 0.5 g., and schroeckingerite, several grams. with the exception of schroeckingeriteit would havebeen desirable if more material had been available for analysis.

*"-*lon ANer,ysrs"**a,Ternlq

Insol., U, Ca, Mg, Na, K
CO:, SOg
HzO
F

Swartzite

Bayleyite

Schroeckingerite

0.1
.05
.06

0.2
.1

0.3
.15
.15
.02

. l

Accepted standard procedures were used in the analyses and for thisreason only a very brief description of the procedures is given below.
The analysis of andersonite involved a few unusual proceduies and theseare described separately.

URANIUM

MINERALSPROM THE HILLSIDE

MINES

Pnocnnrrnus:
l. Determinali.on of insoluble material, U, Ca, Mg, Na, K
Dilute HCI was added to the sample in a platinum dish and the mixture was digestedon the steam bath for 30 minutes. The solution 'lvas then evaporated to dryness. It was
taken up in hydrochloric acid and evaporated to dryness again. Dilute HCI was next
added and the solution digested a few minutes. The insoluble material was filtered ofi,
washed with dilute HCl, ignited, and weighed. The filtrate was boiled gently to insure
the removal of carbon dioxide and a double precipitation with a slight excess of redistiiled ammonia was then made. The RzOs group obtained was filtered off, ignited, andweighed. The RrOa group was then fused with KzSzOz and the melt dissolved in 50 ml.
of dilute HrSOr (7+93). After cooling to room temperature, the solution was passed
through a small Jones reductor. It was then aerated and titrated with standard KMnOr'
The UsOs figure obtained by titration agreed very closely with the weight of the ignited ReOBprecipitate obtained previously. The titrated solution was then concentrated
to 50 ml. by evaporation and the reduction and titration repeated as a check.
The filtrate from the ammonia precipitate was treated with oxalic acid and the calcium
oxalate obtained after double precipitation was ignited to CaO and weighed.
Magnesium was determined in the filtrate from the calcium oxalate by first destroying
ammonium salts and oxalate, precipitating magnesium with 8-hydroxy-quinoline, igniting
the precipitate under cover of oxalic acid to MgO, and weighing. The filtrate from themagnesium was taken to dryness and the ammonium salts and organic matter were destroyed by gentle ignition- Suifuric acid was added to the residue, the solution evaporated
on the steam bath and then on hot plate to remove the excess sulfuric acid. The sulfatesobtained were ignited (temp. about 750") and then weighed as NazSOrtK:SOn. Potassium
was then determined as potassium chloroplatinate and the sodium determined by difierence.
2. Determi.nation of COz and, SOs
Carbon dioxide was determined, using a standard absorption train. The SOa content
was obtained gravimetrically as BaSOr on the solution from the COz determination.
3. Determination oJ fluori.ne
The fluorine was distilled with perchloric acid and then titrated with standard thorium
nitrate after the solution was adjusted to a pH of 3.0 with monochloracetic acid-sodium
monoch'oracetate buffer. Sodium alizarin sulfonate was used as indicator.
4. Delerminolion

oJ total water

Water was determined by the Penfield method after first mixing the sample with dry
NazWOr to hold back oxides of sulfur. Before weighing and after the water was collectedin the tube, the tube was inciined at an angle of about45"for 30 minutes, open end down
to allow the carbon dioxide released bv the samole to be replaced bv air.
Anolysis of and.ersonite
The sample was weighed and transferred to a platinum dish. About 5 ml. of water wasadded and carbon dioxide was determined by titrating the sample with standard 0.011[
HCI to the methyl orange end-point. This method for the determination of carbon dioxide
was used after testing the more abundant bayleyite by titration and absorption train.
The two methods gave good agreement in the results for carbon dioxide. After the titrationa drop of concentrated HCI was added and the solution boiled gently. It was then cooled
and 5 drops of dilute barium chloride solution were added. The cloud of BaSOr was thenmatched against standards and the value for SOs lvas thus obtained. The BaSOr was thenT. M. AXELROD, F. S. GRIMALDI, C. MILTON, K. J. MURATA
digested for some time and allowed to settle overnight. This was filtered ofi and rejected.
In the filtrate uranium was precipitated as before, and after fusion of the ignited ammonia
precipitate in KzSzOz it was determined colorimetrically with NaOH-HzOz.
The filtrate from the ammonia precipitate was taken to dryness and the ammonium
salts destroyed. Calcium was precipitated again as the oxalate but from very small volume.
It was filtered off and ignited to CaO. The CaO was then titrated with standard 0.011[
HCl. A check on the calcium figure was obtained as foliows: Oxalic acid was added to thetitrated solution and the mixture was evaporated on the steam bath to remove chloride.
The dish was then heated gently over a flame to remove the oxalate and finally the sample
was ignited to CaO. The residue was then titrated ivith standard HCl. Rromthymol blue
is recommended for acid-base titrations with 0.01d solutions.
The filtrate from the calcium oxalate was taken to dryness and the ammonium salts
destroyed. The alkalies were weighed as sulfates and then sodium was determined by
precipitating with zinc uranyl acetate.
DISCUSSION or. THE ANALYSES. Contamination

with gypsum

Andersonite, swartzite, and bayleyite contained CaSOr ZHzO (gypsum) as impurity.
SampleAndersonite
Swartzite
Bayleyite

To besubtrocted
Impurily (/6 oJSample)
from tkeonalysis
3.4/6 CaSOa.2HzO 1.670So€,1.1/6CaO,o.TToHrO
4.26/oCaSOa'2HzO 1.98705U,1.39/6CaO,o.8970HrO
8.45/6CaSOt.2HzO 3.93705U,2.75/sCaO,l.77ToHrO

The contamination of these minerals was to be expected in view of
their intimate associationwith gypsum. Only the schroeckingerite,which
occurs in relatively large homogeneousaggregates,appearsto be essentially free from gypsum. That the contaminant \,vasgypsum was shownby optical examination. Further, it appearedthat, by synthesizingthe
severalsubstancesin the absenceof sulfate ion, the SOaof the analyses
was not part of these mineials. X-ray difiraction patterns did not reveal
the gypsum, as it was in too small a quantity.
In Table 3 are the analyses with the constituents of the admixed
gypsum deducted. The molecular ratios are then computed to obtainthe formulas of the new minerals. The SOsof the analyseswas the basis
for allotment of CaO and HrO to CaO . SO3.2H2O,gypsum; a reasonable
and proper assumption, inasmuch as andersonite,swartzite, and bayleyite
contain no SO3; and the arlalyzed schroeckingerite, which does containSO3,was known to be free from admixed gypsum.
Notes on analytical data
Although the analysisindicates17.43moleculesof water in the bayleyite formula, there is a strong presumption that 18 is the correct figure,and that the lower value indicates that spontaneous dehydration of
bayleyite had already commenced before the water determination was
made. The 12 and 6 molecules of water present in swartzite and ander-MINERALS FROM THE HILLSIDEURANIUM

MINES

sonite, respectively, suggest that a similar multiple of 6, that is 18, ismore Iikely than an odd number such as 17. Furthermore, the density
calculated for 18 H:O agrees better with the measured density' For
thesereasons,the higher water content is assumedto be the correct one.
Except for bayleyite, specific gravities were obtained by suspending
one or two grains of the mineral in a liquid of the same gravity.
Teslr

3. CoupurarroN

Andersonite

MgO
CaO
NarO
Uo:
HzO
coz
sos

0.5
8.9
9.3
43.4
16.7
19.6
1.6

100.0

Gvpsum1.1

0.7

ol Fonnur,es FRoM ANALYSES
Remainder

Ratio

0.5
7.8
9.3
43.4
16.0
19.6

Y
::l
L.5e)

1 . s o rx. o

1.50
1.52
8.88
4.45

1 . 5 0 X1 . 0
1 . 5 0 X1 . 0
1 . 5 0 X5 . 9
1 . 5 0 X3 . 0

1.6

3.4

96.6

Deduced formula CaO 'NazO 'UOB ' 3CO, 6HrO
NarCa(Uoz)(COr)r'6HzO. As indicated, a slight replacement of calciumorby magnesium may exist.
The formula of andersonite also can be computed from the analysis of the synthetic
material:

CaO
Na2O
UOa
H:O
COz

Ratio

Andersonite(synthetic)
8.80
9.61
M.27
16.50
2A.6r

t.57
1. 5 5
1..)J

9.17
4.69

1 . 5 5 x .01
1 5 5 X .00
1 . 5 5 X .00
1 . 5 5 x5 . 9 r
1 . 5 5 X3 .03

99.79
Deducedformula CaO'NazO 'UOs '3COr'6HrO
or
NazCa(UO:)(COt'6H,O

Mso
CaO
NazO
IGO

UO:
HzO
COz
SOs
Insol.

Swartzite
5.24
8.40
.25
.47
37.t9
29.31
17.16
1.98
.30

Gypsum100.30

4.26

r.39

.89

Remainder
5.24
7. 0 r
.25
.47
37.19
28.42
17.16

1.98

95.74

Ratio
1. 3 0
l.z5

.04
.05
1. 3 015.80
3.90

1.30x1.00
1.30x .96
1.30X .03
1.30x .04
1 . 3 0 X1 . 0 0
1.30x12.15
1 . 3 0 X3 . 0 0

10T, M. AXELROD, F. S. GRIMALDI, C. MILTON, K. J. MURATA
Tesro 3 (continued)

Deduced formula NIgO'CaO .UOB .3CO, .l2H2O
or
MgCa(UOr)(CO3)3.72H2O

Meo
CaO
NarO
KrO

UO:
HsO
COz
SO:
fnsol.

Bayleyite
8.97

Gypsum

z.t5

2.75

.19
.09
32.42
36.60
1 5. 3 6
3.95

Remainder
8.97

Ratio

2.220

1 . 1 1 x2 . 0 0.03.01
1. 1 3 3
1 9. 3 5 0
3.491

1 . 1 1 x1 . 0 2
1 . r 1 x 1 7. 4 3
1 . 1 1 x3 . 1 5

3.93

.19
.09
32.42
34.83
1 5. 3 6.02

8.45

9 1. 8 81.77

4{100.78Deducedformula 2NIgO.UOr .3COr. 18H2O
or
Mgz(UO)(CO:): 18HzO
MsO
CaO
NazO(Na)
KrO
uoa
HrO
co:
SO:
F
Insol.

Schroeckingerite.63
18.M
3.19 (2.36)
.23
31.28
20.20
14.67
9.24
2.09
1 .53

L e s sO : F

1 0 1. 5 0
.88

Ratio
.lo

3.29
(1.03).02
1.09
tl .22
3.33
I .lo

1.10

I .09x 3.02
1.09x .95
1.09x1.00
1.09x10.29
1 . 0 9 x3 . 0 5
1 . 0 9 x1 . 0 6
1 . 0 9 x1 . 0 1

r00.62The deduced formula is Ca:Na[UOr(COt3SO4F] .10HrO, u'hich is the same as thatderived by Jafie, Sherwood, and Peterson.

In view of the small quantity (3.8 milligrams) of andersonite available
for analysis,it was thought proper to verify the calculated formula bymeans of a second analysis made on synthetic material. Mrs. Marie
Eiland, chemistof the U. S. GeologicalSurvey, kindly made this analysis.
Both analyses are given in Table 2 above, and it is evident that theagreement is satisfactory.
The analysis of the Arizona schroeckingerite was made before thepublication of the study of the Wyoming schroeckingerite by Jaffe,
Sherwood, and Peterson.l fn these circumstances,it is gratifying to notethat the two analyses agree closely. Better agreement could hardly be

URANIUM

MINERALSFROM THE HILLSIDE

MINES

11

expected, considering that the respective samples are from different
Iocalities, were analyzed by different chemists, and are substances ofcomplex composition. The agreement is of special significancein that the
deduced formula CarNa[UOz(COra(SOrF] 10HrO (which may be rewritten 3CaCOa NaF'(UOz)SOa 10HzO) independently obtained by
Jaffe, Sherwood, Peterson, and by ourselvesdiffers from the lormula
hitherto ascribedto dakeite (: schroeckingerite)by Larsen and Gonyera
n a m e l y 3 C a C O a ' N a z S O a ' U O s ' 1 0 H 2i n
O h, a v i n g o n l y h a l f a s m u c h N a 2 O ,and in containing essentialfluorine.
Dr. Clifford Frondelo of Harvard University has observed (personalcommunication) that there is a difierence in size of the unit cells of theBohemian and the two American schroeckingerites.Both of the latter
agreecloselyin r-ray pattern as well as chemicalcomposition.If a similarIy good analysis of the Bohemian mineral were available, a significant
difference in composition might be shown.
Spectuographic Data
Tegra 4. Spncrnocnepnrc
Major elements

Minor elements

>l7o

<17o

Schroeckingerite

U, Ca, Na

Bayleyite
Bayleyite (purer sample)
Andersonite

U, Mg Ca(370)U,l'{g, Ca(lTo)v, Ca(a/),
Na(11lr)
U, Ca(r4/),

Swartzite

Srunv

Not found

Mg, Al, Fe,
K, MN
AI
AI
Al, Ms(O.s%)

Sr and*AI, SrFe, Mn, Na, K, and*Al, FeMn, Na, K, Sr, and*Fe, Mn, Na, K, Sr, and+Fe, Mn, Na, K, Sr, and*Fe, Mn, K, Sr, and*

Ms6%)
Dehydration product ofbayleyite and of swartzite (mixture)U, Mg, Ca(lTo)* Not found in any: Be, B, Pb, Cu, IIo, W, As, Sb, Sn, Tl, Zn, Cd, Co, Ni, Ge, In,
Cr, V, Y, La, Bi, Ag, Li, Rb, Cs, Ti,Zr,Ba,Th.
The numbers in parentheses indicate the spectrographically estimated pelcentages;
they indicate order of magnitude rather than exact pelcentages, and are thus in reasonableagreement with Grimaldi's analytical figures.
part, theThe minor elements detected spectrographically are referred to impurities-in,.insoluble" of the analyses. A possible exception is the0.5/e Mg found in the andersonite.
The notably less Ca in the purer sample of bayleyite indicates that the Ca present is
not a constituent of the mineral.

SvNrunsrs oF TrrE Nnw MrNnnar-s
The synthesis of these compounds was undertaken in order to verify
beyond question that the r-ray difiraction patterns were those of com-

12J. ],T. AXELROD, F. S. GRIMALDI, C. MILTOi,

R. T. MURATA

pounds of the deduced chemical compositions,and, also, in the caseof
the andersonite to have an analysis free from the uncertainty arisingfrom the minute quantity of natural substanceavailable. The literature
did not show that they had beenpreviously prepared, but the homologous
substanceslisted below had been.7(NH4)UOr(CO;)B.2HrO
NarUOz(COa):
KnUOz(COs):AgrUOz(COr):
TI4UO'(COJ3CazUOz(COr)s
BazUOz(COr)s(The indicated H2O content, or its absence,
is of doubtful validity.)

The methods given for preparing these compounds were successfully
employed by us to prepare synthetic andersonite,swartzite, and bayIeyite.
Details of the synthesisfollow:
For bayleyite, MgrUOr(CO3)a.1SHzO.
Proportions used of starting materials:
MS(NOB)z'6HrO
UOr(NOt, '6HrO
KzCO:

Mol. Ratio
2
1
3

Weighk
513gm.
5.02 gm.
4.14 gm.

Add slowly the uranium nitrate solution to the KzCOa solution in thepresence of phenolphthalein as indicator. If the indicator decolorizes,
add KzCOr solution until the indicator is just barely pink. Now add
magnesium nitrate solution. If the phenolphthalein decolorizes, add
KzCOasolution until the indicator is just barely pink. Allow to crystallize
at room temperature.
Bayleyite also was synthesized by first preparing the insoluble silver
uranyl carbonate, reacting an excessof the silver uranyl carbonate withmagnesium chloride, filtering off the precipitate of AgCI and excess
silver uranyl carbonate, and allowing the filtrate to crystallize. Sometimes
a gelatinousmassformed on drying, but by "seeding" this mass crystallized nicely (Figs. 3a and 36). The reaction is AgrUOz(COr)r*2MgCh* 18HzO--+bayleyitef 4AgCl.
Andersonite was synthesizedsimilarly to bayleyite.

Ca(NOr):.4HzO
NaNOr
KZCO:
UOr(NOs),'6HrO

Molecular
Ratio
I
2
3
1

w etgttts
2.36gm.
1 . 6 2g m .
4.14gm.
5 . 0 2g m .

Again the uranium solution was added to KrCOa solution and theURANIUM

MINERALS FROM THE HILLSIDE

MINES

13

acidity was adjusted with KzCOauntil the phenolphthalein was just pink.
Then a solution of NaNOa and Ca(NOa)zwas added, the acidity was
adjusted as before and the mixture was allowed to crystallize at room
temperature.
At first there was some difficulty in synthesizing swartzite by similar
proceduresl on evaporating a solution of the constituents a greenishyellow glass, or better, gel, of refractive index near 1'53 forms, but on"seeding" with a fragment of the natural mineral, excellent crystals
develop.

Frc. 1 X15
Swarlzite CaMgUO:(COa)r12HrO
Yavapai County, Arizona

Fro. 3aF r o . 2X 1 5
Andersonite Na:CaUOz(COa)s' 6HO
Yavapai County, Atizonax38

Frc. 3bBayleyite MgzUOz(CO:)g' 18H:O (Synthetic)
The synthetic preparations yield acicular crystals; the natural bayleyite was stubby
prismatic, with good terminal faces.

14

J. M. AXELROD,F. S. GRIMALDI, C. MILTON, K. J. MURATA
Rruenr<s oN TrrE Holrorocous XaUOz(CO)r.nHzO Srnrrs

As already mentioned, numerous synthetic compounds of the above
general formula are known, in which Xa ma1r represent four univalentions, two similar divalent, or, as in the naturaily occurring minerals,

Frc. 4. Powder patterns of uranium minerals and synthetic preparations (filteredcopper radiation)
2777 Bayleyite, Arizona
2866 Bayleyite, Synthetic
2791 Andersonite, Arizona
2869 Andersonite, Synthetic
2780 Swartzite, Arizona
4266 Swartzrte, Synthetic
4004 Dehydration product of bayleyite, Arizonatt005 Dehydration product of bayleyite, Synthetic

URANIUM MINERALS FROM THE HILLSIDE MINES

15

two different divalent, or two univalent and one divalent, ions. It would
be of interest to determine how extensively the seriesextends, whether
a univalent and a trivalent ion, or a single quadrivalent ion could function as Xa. The varying value of z, determined for a large number of thecompounds, should be of interest from a theoretical structural viewpoint.
Also, the variation in fluorescenceof the naturally occurring compoundswith varying states of hydration, now an unexplained feature of thisclass of substances, could perhaps be clarified by a study of a large
number of these homologues,in which the variations in cation and watercontent are known factors.
X-nav INvBsrrcarroN
X-ray powder and Weissenberg diffraction patterns were made ofandersonite,swartzite, and baylbyite. Powder patterns were made ofthe dehydration products of swartzite and bayleyite, and also of schroeckingerite. "Randite" (:B-uranotile), uranothallite (:liebigite), "voglite" (often actually liebigite), "rutherfordine" (:an undescribedcalcium uranium silicate) also were studied by their powder patterns.
Data Jrom powd.erpatterns
Table 5 gives the powder pattern data on the new minerals.
The error figures are estimates. The diffraction data for andersonite
and swartzite were inconclusive as to the presenceof a center of symmetry, so piezoelectric tests were made through the kindness of Paul L.
Smith at the Naval Research Laboratory in Washington. The crystals
showed no piezoelectricity, so that this test also was inconclusive. Noneof the crystals had enough faces to determine the crystal class frommorphology or good enough faces to make etch tests practicable.
TnB NBw MrNnner- N.q.urs
Andersonite is named after Charles A. Anderson, geologist of theUnited States Geological Survey, who first observed and collected thematerial from which these minerals were isolated and identified.
Swartzite is named for Charles K. Swartz (1861-1949),professorof
geology and mineralogy at The Johns Hopkins University, an inspiring
teacher oI mahy generationsof students.
Bayleyite is named in honor of William S. Bayley (1861-1943),for
many years professor of mineralogy and geology at the University of
Illinois, and geologist with the United States Geological Survey.
The naturaliy formed dehydration products of bayleyite and swartzite
are not proposed as species.Although the dehydration product of thebayleyite, at lbast, yields a characteristic and definite *-ray diffraction-

16

J. M. AXELROD, F. S. GRIMALD|, C. MILTON, K. J. MURATA
Tmr,n 5. Powonn PerrrnN Dere (rrr,rrnrD coppERn.Lorarrox)
r : 1 . 5 4 1 8A
Andersonite, ArizonadIhkt,dIhkl,
13.0
10
100
9.51
3
101
7.97
10
111
6.56
2
200
5.68
10
102,112
5.22
10
Tl2,1t2
4.35
6
122
4.19
6
103
4.04
4
713,103,222
3.82
3
113
s.71
8
203,222
3.49
2
723
3.34
2
223
3.15
5b
303,223,223
3.00
7
T33,114,303
2.79
6
2 .45
5
2.3953.11232I
2.36
4
2 .21
7
2.04
4
2.Ol
4
|.977
4
r.957
4
1.933
4
1.895
4
7.852
6
1.749
5
1.684
3
1.573
4
1.393
3
r.344
3
r.262
3
1.232
3
1.038
2
.9803
2
.9505
2
.8192
2
.8011

2
b.' Broad

Swartzite, Arizona

8.76
7.3r
6.37
5.83
5.50
5.13
4.82
4.62
4.46
4.37
3.85
3.66
3.53
3.39
3.31
3.25
3.19

10
9
5
1
10
1
8
2
2
2
2
7
5
t
I
I
7

110
020
001
011
1rl,2OO
210
ltt,}2l121
20I,130220
20r
040,230310
221
23I,3rI
320
102,002

3.04
2 .91
2.82
2.61
2.28
2.23
2.19
2.r0
2.06
1.817
1.707
1.375
1.268
r.2r7
.9615

|
g
2
5
4
3
2
2
8
5
8
2
2
3
2

240,231022,2t2,3ll(The dehydration product of swartzite isamorphous to r-rays)

IIRANIUM

MINERALS FROM THE HILLSIDE

M]NES

T.q.sln 5 (continued)
Bayleyite, Arizonad
1 3 .1
7 .66
6 .5 3
5.85
5.08
4.89
4 . 7|
4.54
4.4r
3 .8 33.70
3.26
3 .1 5
3.05
2.96
2.88
2.69
2.42
2.37
2.30
2.21
2.12
1.908
1.796
1.754
1.682
1.378
1.247

9
t0
4
4b
A

4
I
o
a

6
2
i
o
a

hkt
200,110
310,020400,220,001
201,tlt,t7l
311
021,31I,40t
221,22140T
330,600
620,040
33r,710,530,24-0002
ll2,2l2 (n.r.)
3r2(n.r.),730,911

45Dehydration product of bayleyite,
Arizona

d
8.27
7.25
6.24
5.54
5.34
5.13
4.77
4.62
4.51
4.42
4.23
4.00
3.75
3.56
3 '49
3.20
3.11

I
10
2
1
I

(
3
9
2

z

3
4

s.o7
2
(
4
3b
2b
2b
1
1
a
I

2.r..' Not recorded on any Weissenberg filmb.'Broad

3.02
2.89
2.86
2.76
2.7r
2.64
2 -47
2.M
2.32
2.26
2.t4
2.r2
2.08
2.05
1.973
1.881
1.848
1.811
1.787
1.752
1.695
1.578
1. 5 5 1
I.352

.1

2
2
3
.t

4

2
3
4
3
3
J

2
I
J

n

3
2b

18

J. M. AXELROD, F. S. GRIMALDI, C. MILTON, K. J. MURATA
Tesrr 6. Cnvsrar,rocnalnrc Dlra lnou SrNcr,nCnvsrer WrrssrNsrnc
X-n.cv Srr,'Dy
A nd.ersonile: NarCaUOr(CO:): 6HrO
a:13.11+.02 A Spu." group:R3(C3;r)or R3 (C3a),rhombohedral
a:86'56'*30'
Z:6.
For the hexagonaldescription:a : 1 8 . 0 4 + . 0 5A Z : t S
c : 2 3 . 9 0 + . 0 5A
c/a:1.325.
Calculateddensity:1.96(2.8measured).
. 12HrO
Swartzite: CaMgUO:(COs)3
a:71.12+.05 A Spacegrotp: P211m(C2n2)
or P21(C2z),
monoclinicb : 1 4 . 7 2 + . 0 5A Z : Z
c: 6.47+.02 A. Calculateddensily:).92 (2.3measured).
8:99"26'-r30'
Bayleyite: MgzUOz(CO:)s'
18HrO
a:26.65+.OS A Spu." grottp:P211a(C27,5),
monoclinic
jr Z:+
b:15.31+.05
c: 6.53+.02 A. Calculateddensity:2.06 (2.05measured).
F:93o4'-t20'.

pattern,

this is not considered sufficient grounds for establishing a newmineral species, for the pattern may be that of a mixture.
Sylropsrs or URANTLTMCannoNqre

MrNrnars

A tabulation of the known uranium carbonate minerals is given below
in Table 7, followed by more detailed discussion of the status of theseveral species.
Tesln 7. UnexruM-Cansoxarr Mrnonars

Speciestiebigite

Ul1t
^.
,
ulscoveted1848

Composition (reported)
CaUOz(COr)g' 20H'O (eroneous) seeuranothallite below
contains Ca, Cu, HrO

Color
apple green

Remarks
established species:liebigite? (in part)emerald-greento
bright grass-green
schroeckingerites 1873
NaCarUOr(COa)aSOnF'10H,Ogreen
well-establishedspeciesranditeyellow
1878
is impure B,uranotil"hydrous Ca-U carbonate"uranothallite
1853-1882CarU(CO)6'10HzO
siskin-green
liebigite has priority
yellowrutherfordine
1906
UOTCOT
dubious (not a carbonate)sharpiteyellow-green
1938
6UOr' SCOr' 8HrO
needs{urther study
studtiteyellow
1917
U-Pb?-H'O-CO'
needs further study
diderichiteyellow-green
194?
U-H,O-CO,needs lurther study
green
andersonite
1948
NazCaUOr(COr)r'6HrO
swartzite
1948
CaMgUO,(CO')'' 12H'O
sreen
yellowbayleyite
1948
Mg"UO'(CO')r' 18H,O
voglite1853

URANIUM MINERALS FROM THE HILLSIDE MINES

19

Liebigi.te
Considerableconfusion has existed in the past as to the status of liebigite. In 1848J. LawrenceSmithedescribeda mineral under this name from
Adrianople, Turkey, as a hydrous carbonate of calcium and uranium.
He computed a formula CaCOs.(UODCO3.20H2O
L .a t e r , i n 1 8 5 1 , 1 0
he mentioned another occurrenceof the same mineral from Johanngeorgenstadt.In 1853the same mineral (as establishedby Evans and Frondellr in 1949) was describedby Vogl12from Joachimsthaal under the nameUran-Kalk-Carbonate.Finally, in 1882,Schraufl3determinedthat Vogl's
Joachimsthaal mineral differed in composition from that given by Smith,
being CazU(COrr.10HzO,and proposedthe name uranothallite. Smith's
original analysis of liebigite is therefore erroneous, but as Evans andFrondel have shown that his mineral is the same as the correctly determined uranothallite, Smith's name, liebigite, has priority. Weisbachta
in 187.5proposed the name flutherite, which under the circumstanceshas
no standing.
V ogli,teVoglite was first described by Vogl12in 1853, from Joachimsthaal,
as a copper calcium uranium hydrous carbonate. The name voglite wasproposed by Haidinger in a footnote to the original description by Vogl.
There is no reason to question its validity as a species,although, as noted
byFrondel,ll "Most specimenssolabelledare uranothallite," i.e.,liebigite.
Such was the case with U. S. National Museum specimenR2763 from
Joachimsthaal(Roebling collection).
S chroeckingerite
Schroeckingeriteis discussedabove.
Rand.ite
Randite was first describedby August Koenigls in 1878 as a canaryyellow incrustation of acicular tufts on granite, at Frankfdrd, near Philadelphia, Pa. An analysis of 47 milligrams of impure material is citedby Dana, System,6th Ed. p. 309, as indicating a hydrous calcium uranium carbonate. It differed from liebigite and voglite in color, being yellow,
whereas these two are green. An imperfect analysis gave a formula
CarUgCoOro'3HrO.
The author proposedthe name randite, with a reservation that the mineral needed further study before acceptance as a new
species.
A specimenfrom the United States National Museum R2765 (Roebling Collection) of so-called randite shows a thin waxy crust of green-

20

J. M. AXELROD, F. S. GRIMALDI,

C. MILTON, K. J. MURATA

ish yellow color. Microscopically, extremely small needleswith ill-defined
optics can be seen,but it was impossible to obtain enough for quantitative analysis.
Ilowever, from Dr. Frondel it was learned that the original randite"is a gross mixture of p-uranotil, tyuyamunite, kaolin, and calcite, with
the B-uranotil dominant and representing the acicular crystals. . . . "16
Further, Frondel observes,"An authentic specimen of randite from Sam
Gordon proved to be tyuyamunite. Other specimenslabelled randite were
B-uranotil."17The National Museum randite above mentioned (R2765)
gave an r-ray powder pattern similar to that of F-uranotil from Joachimsthaal (H7644 from the Harvard collection).
The suggestion of Ramdohrls that randite may be uranothallite, istherefore untenable.
A definitive study of randite by FrondeFepublished recently shows it
to be a mixture of known minerals, it is therefore to be discredited as a
species.
Uranolhall,'ite
Uranothallite is discussedabove.
Rutherford.ine
Rutherfordine was describedin 1906by W. Marckwald20from German
East Africa with the formulaUOz.COa.We have studied the U. S. National Museum specimen 93291 so labelled, and found its *-ray diffraction pattern to be the same as that of a presumably new calcium uranium
silicate from Mitchell Co., N. C., in the Harvard collection (personalcommunication from Clifiord Frondel). The speciesis therefore not to
be included among the uranium carbonates.
Sharpite
Sharpite was described in 1938 by J. Melon2r from Shinkolobwe, Belgian Congo, as 6UOa'5CO2.8H2O.No r-ray data are available, but its
identity as a speciesrests on an analysis and optical data.
S tudtite ond.d,iderichite
Studtite and diderichite were described in t947 by J. Vaes'z2from
Shinkolobwe, Belgian Congo, as possibly uranium carbonates.The comment of Michael Fleischer23on these proposed names is justified: "ft is
to be regretted that new names were given to these very poorly characterized mineralb. . . . It would be better to hold up publication of descriptions like these until enough data at least were obtained so that future
workers could recosnize the minerals from the descriptions."

MINERALS FROM THE HLLLSIDE MINESLTRANILTM

2I

AcxNowrBoGMENTs
Our thanks are due Michael Fleischer and Earl fngerson of the UnitedStates GeologicalSurvey who have read and instructively commented on
the manuscript of this paper. Professor Clifford Frondel of Harvard University has kindly checked the several x-ray patterns of the new uranium
minerals against the extensive file at l{arvard, and we have borrowed
freely fiom his detailed knowledge of the uranium minerals, in particularwith referenceto randite, Iiebigite, and rutherfordine. Dr. L. J. Spencerof the British Museum has advised us as to nomenclature of the new
species.Judith Weiss Frondel of the United States Geological Survey
helped in checkingthe literature of recordeduranium minerals. George
Switzer of the United States National Museum furnished specimensof
type material on which comparative studies could be made. Paul L.
Smith of the Naval ResearchLaboratory made tests for piezo-electricity.
RnlnnrNcrs
1. Jalrn, Howano W., Snrnwool, Ar,rxa.Nlrn M., aNl Pntnnsox, M,tunrcn J., Newdata on schroeckingerite: A m. M inerol, 33, 152-157 (1948).
2. Geronerrn, Fnnnrnrc Wrr,rrnlr,3rd, Minerals of Arizona (2n ed. revised): Arizona
Bureau oJ Mi,nes, Bul,l,elin 153 (1947).
K J., ano Surra, R. L., Manganese and lead as coactivators of red fluo3. Mun.ltl,
rescencein halite: Am. M,ineral, 31, 530 (1946).
4. L.rnsnx, E. S., Jn., aNl GoNvrn, F. A., Dakeite, A new uranium mineral from
Wyoming: Am. Mineral., 22, 561-563 (1937).
5. Nov,(cnr, R., The identity of dakeite and schroeckingerite; Am. Mineral.,24r317{.23(1939).
6. Letter, Clifiord Frondel to Charles Milton, January 27, 1948.
7. Hrovalr,, J. A., Beitrag zur Kenntniss der komplexen Uranyl Carbonate: Z. J. anorg.
Chem., 146, 225-229 (1925).
8. Scnnaul, A., Schroeckingerite, ein neues Mineral von Joachimsthaal: Min. Mitt.,

HeJtII, r37-r38 (1873).

9. Sltru, J. L., Two new minerals-medjidite (sulphate of uranium and lime)-liebigite(carbonate of uranium and lime): Am. Jour. Sci.,5,336 (1848).
10. SnrrH, J. L., Liebigite Am. Jour. Sci., 11,259 (1851).
11. Evaxs, Howar.o, eNr Fnonorr,, Cr,rllonl,Studies on Uranium Minerals (II):Liebigite and Uranothallite, Am. Mineral.,35, 251-254 (1950).
72. Yoct-, J. F., Drei neue Mineral-Vorkommen von JoachimsthaaL fb. Geol'. Reiehs.
(Vienna), 4, 220-223 (1853).
13. Scnnaul, A., Uranothallit, false Liebigite, von Joachimsthaal: Zeit. J. Kr.,6,410413(1882).
14. Wusaecn, A., Syn. M,in. p. 48, 1875 (referred to in Hintze, Carl, Handbuch derMineralogie I, No. 26, 3056, 1929).
15. KonNrc, Aucusr, Mineralogical notes-randite:
Proc. Acail. Phila'd'elphia' 30' 408(1878).
L6. Letter, Clifiord Frondel to Michaei Fleischer, July 11, 1946.
17. Letter, Clifford Frondel to Michael Fleischer, June 19, 1946.
18. Roroonn, Peur., Klockmann's Lehrbuch der Mineralogie, p. 469, Stuttgart (1948).

22

J. M. AXELROD, F. S. GRIMALDI,

C. MILTON, K. J. MURATA

19. FnoNonr, Cmronn, Studiesof Uranium minerals (1): Parsonsiteand Randite,,4z.
Mi.neral,.,35, 245-250 (1950).
20. M,q,ncrwero,W., Ueber IJranerzeaus Deutsch-Ostafrika:CentroJlbl,att
f. Min., Geol.,u. P a1..,24, 76l-7 63 (1906).
21. Mnr,or, J., La sharpite,nouveaucarbonated'uranyl du Congobelge:BulI. Sean.Insl.
Roy.Colon.Belge,9, 333-336 (1938).
22. Yets, J. F., Six nouveau mineraux d'urane provenant de Shinkolobwe(Katanga):
Bul.l.Soc.Bel,geGeol.,70, B, 212-225(1947).
23. Frnrscnrn, MrcuArl-, New mineral names:Am. Mi.neral,.,33,385 (1948).
Manuscript receil)ed
April 8, 1950