ABERNATHYITE, A NEW URANIUM MINERALGROUP*METATORBERNITE

OF THE

NI. E. TuouesoN, Br-eNcno INGnalt, aNo E. B. Gnoss,Lr. S. GeologicalSurttey,Grand'Jwnction, Colo., and' Washington, D' C'
and, U. S. Atomic Energy Commission, Grand Junction, Colo'Ansrnecr
Abernathyite, a new uranium mineral from the Fuemrol No' 2 mine, Emery County'
The mineral occurs as transparent, yellow,Utah, has the formula K(UO:)(AsOr)'4HzO.
fluorescent, thick tabular crystals belonging to the tetragonal system, ditetragonal-dipyramidal class (4lm 2/m 2/m). The space group is P4/nmm ; ao:7 .17+0'0I A; co:9'08:1'57010'003,
Optically, the mineral is uniaxial negative, eiO.Ot A; o:c--l:1.266;Z:2.
gravity is 3.74.
specific
calculated
The2and3.
isbetweeno:1,597+0.003. The hardness-,
The chemical analysis shows, in per cent: KzO,9'5;UO:, 57.7;AszOe,2l'6;P2O5,1'5; HzO
operator
Abernathy,
finder,fortheisnamedJess
4.6;HzOt ,9.9; total, 104.8.Abernathyiteof the Fuemrol mine.
INrnonucrroNAND Acr<Nowr-ToGMENTS

In the summer of 1953, JessAbernathy, operator of the Fuemrol mine,
Emery County, Utah, noticed some yeilow crystals in his ore. Realizingthat they might be of mineralogic importance, he gave the several piecesof sandstonewhich were coated with crystals to E. B. Gross,mineralogist
for the U. S. Atomic Energy Commissionin Grand Junction, Colo' Mr'
Grosswas unable to find in the literature any mineral with corresponding
optical properties, and, not having the facilities in Grand Junction forfurther work, he gave the specimensto A. D. Weeks and M' E' Thompson, mineralogists for the U. S. Geological Survey in Washington' D'C'
The study of the mineral was continued in the U' S. Geological Survey,
as a part of the Survey's program conducted on behalf of the Rawl,Iaterials Division of the U. S. Atomic Energy Commission'
The authors wish to expresstheir appreciation to F' S' Grimaldi, of theU. S. Geological Survey, for his advice and assistancewith the problems
arising in the courseof the chemical analysis. The authors are pleased tonurn.1hi, mineral for the person who found it, JessAbernathy; withouthis interest in and appreciation of the mineralogy of his ore, the mineral
might have remained undiscovered.
OccunnpNcn AND AssocrATEDMTNERALSThe Fuemrol No. 2 mine is on a lower slope of Temple Mountain'on the southeast flank of the San Rafael swell, Emery County, Utah'
about4T miles southwestof Green River, Utah (Fig' 1)' Mining in the* Publication authorized by the Director, U. S' Geological Survey'

82

ABERNATHYITE,URANIAM MINERAL OF TEE METATORBERNITE

83a:(\rJE(D5rN"4WAYNEI CO.

AT

EXPLANATION
pqyEcl16qcl&Groded rood:Ditl
toodO:.

ScoleIlomiles

l'5OOTOOO

Frc. 1. Index map of locality of abernathyite'area is in vanadiferous and uraniferous asphaltic sandstones in theShinarump conglomerate.
Temple Mountain, a small elongate mountain, is capped by Wingate

84

M. E. THOTIPSON, BLANCE INGRAM, AND E. B. GROSS:\F.eeE:-F:-' o E!

=€t:
t:t:tI l+:,:I

Frc. 2. Geology of the "collapse" area at Temple Mt., Emery County, Utah.

sandstone. Beneath the Wingate sandstone, in descending order, are
red standstonesof the Chinle formation, gray Shinarump conglomerate,
and red shalesand sandstonesof the Moenkopi formation. A,,collapse',zone (Fig. 2) about 1,800 feet long and 400 feet wide extends below theWingate sandstone near the central part of the mountain. The area of
disturbed rocks has been called the "flop over" or the "tongue.,,
Within the disturbed area the sandstonehas bleached white or gray,

85
ABERNATHYITE,T]RANII]MMINERAL OF THE METATORBERNITEofIacks bedding features, and is much fractured' fn the upper portions
exare
sandstone
hematitic
the flop over, large massesof goethitic andposed.
At the Fuemrol No. 2 mine near the lower end of the flop over, theinsandstoneis iight to clark gray and contains nodular massesranging
grainssandofcomposedarediameter from 1 to 5 inches. The nodules

gray clay aggregate.
theAbernathyite occurs as a crystaliine coating lining a fracture inNo
scorodite.
sandstone and is associated with yellow-brown earthy
samplesintheother minerals were found associatedwith the new mineralminethat were avaiiable for this study, but other specimensfrom thecomoral(T'Stern,W'contain native arsenic' orpiment, and realgar
uranylothertwomunication). Jarosite, pitlicite, metazeunerite, andarsenatesof uncertain composition have also been found'Pnvsrcer- AND OPTTcALPnopBnups
The crystals of abernathyite are unusually clear and transparent fora mineral of the metatorbernite group' They are yellow, have vitreous(3660
Iuster, and fluorescemoderately a yellow-green color in both longpaleA) and short (2537 A) wavelength ultraviolet light. The streakisyellow.
The crystals are thin to thick tabular in habit and occur singly and ingroups. Prominent forms are {001} and {110}' They show a perfectother
Lurul .l.urruge, but the cleavageis not micaceous as is typical ofgroup.
metatorbernite
theminerals of
The hardnessis between 2 and,3. As the largest of the crystals is onlytests
about 0.5 mm. on an edge, it was necessaryto observe the scratch
microscope.
for hardnesswith a binocular
An insufficient amount of the mineral was available for a direct measiourement of the specific gravity, but the crystals sink in methylene
as3.74
calculated
isgravity
dide of specific gravity 3.32. The specificfor the pure K(UO2)(AsOD'4HrO compound.
yellow, andAbernathyite is uniaxial negative, a:I'597+0'003,
crystals aretheoffew
e:1.570*0.003, pale yellow to colorless'A
degrees'5
anomalously biaxial negative, with 2 V IessthanM. E. THOMpsoN, BLANCHE INGRAM, AND E. A. GROSS

Cnnurcar- Axar,ysrs
A qualitative spectographicanarysis by K. E. valentine, of the Geological Survey, showed U, As, P, and K present in amounts more than 1

Becausequestions might be raised about the value of a chemical analysis for which such a small amount of material was available, some ofthe precautions taken in the analysis are stated here. These precautions
consisted mainly of duplicate analyses and of ,.trial runs" on artificialmixtures. rt was possibleto make up artificial mixtures containing nearly
the correct proportions of As, K, U, and p in advance of the Jemical
analysis, becausethe spectrographic analysis, the r-ray powder pattern,
Tesln

1. CHnurcar, Allerysrs

or AennwarHymn

Analyst: Blanche Ingram, U. S. Geological Survey

Analysis ofabernathyite

KzO
UOs
AszOs
PsOo
HrO+
HsOTotal HgO

9. 5 rs 7. 7 22r.6
1.5

9.1
55.1
20.6
1.4

(e.e)

(e.4)

(4.6)
1 4 .5 3(4.4)

104.8
I A value of 8.8 perAnalysis recalculated to 100
per cent

K(UOz)(AsOr)'4HzO

9.0
5 5. 022.2

1 3. 8

13.8

100.0

100.0cent KzO was obtained in the first analysis. The analysis was thenrepeated on a larger sample, taking advantage of the information
obtained from the firstdetermination. The value of 9.5 per cent KeOls consideredmore accurate.
2 Average of 57.6, 57.6,57.9.
3 Average of 14.5, 14.4.

ABERNATHYITE, URANIUM MINERAL OF TEE METATORBERNITE
Ttnrl

2. Mornculen R.trros ol ColpolleNrs ol Amruernvrrn
Analysis

KrO
UOa
AszOs
PzOs
HeO*
HzO-879.5s 7. 72t.6
1.5
9.9
4.6

Molecular
weightMolecularratios94286
230

r421818

and the physical properties of the new mineral made it fairly certainthat the mineral was a member of the metatorbernite group and that its
formula was probably K(UO) [(As,P)O+]'nH2O.
The uranium determination was repeated three times; total HzQ wasdetermined twice. Potassium was determined gravimetrically twice, thefirst time on a sample of 5 mg. original weight after HzO-, HrO*,
As2O5,and IlOa had been determined. A second analysis for potassium
was made by F. S. Grimaldi, of the GeologicalSurvey, on a 10-mg. sample
which was treated with HCI and HBr to remove the arsenic. The potassium was then precipitated directly. These repeat analysesgave consistent results.
The results of the chemical analysis total 104.8 per cent. No explanation for this high total is offered. The analysis, when recalculated
to 100 per cent, agrees very closely with the theoretical composition(Table 1).
The molecular ratios obtained from the analysis are very close to ideal
proportions (Table 2). The simplest formula to be obtained from theseratios is K(UO) (AsO4). 4H2O. A small amount of phosphorus substitutes
for arsenic in the ratio of one part. P2O5to 14.4 parts As2O6by weight'X-Rav Der,lAn *-ray difiraction powder pattern was taken by D. D. Riska, of theGeologicalSurvey, with a Debye-Scherrercamera (114.59-mm.diameter)using Ni-filtered Cu radiation. The pattern of abernathyite very closely
resemblesthe patterns of several other members of the metatorbernite
group-synthetic hydrogen-autunite, metatorbernite, and metazeunerite. The pattern was easily indexed by comparing it with a pattern ofanother member of the group whose cell dimensions were known (TableJt.

The cell dimensions of abernathyite and several other minerals andartificial compounds that are generally consideredto belong to the meta-88

M. E. THOMPSON, BLANCHE INGRAM, AND E. B. GROSS
Tasln 3. X-Rlv Dmrnacuor Powoen Dera. nnn UNn-Crr,r,CoNsreNrs ol AsrnNTaruvrrr
Spaceg r o u p :P 4 / n m m ;a o : 7 . 1 7 1 0 . 0 1A ; c o : 9 . 0 8 + 0 . 0 1A ;a o : c o : l : l ' 2 6 6 :Z : 210,broad
4
4+8, broad
7d(*t \hkt

9.r4

9.08

JOJ

J. OJ

J.II

5.07
4.54
4.43
3.84
3.59

001
101
110002
111
102
200
112
201

4.58
4.433.84
3.59

8

3.34

I

3.16

\r .s+

3.02

{t.ot

6, broad

2.79

iz.sr

5, broad

2.61

35

2.54
2.45

3

2.32

6

2.28

t3.02

\2.7e
12.63
12.62
1<n2.44

J2.3r\z.sr
12.27|2 . 2 7
(t6

2.21

266

2.r7
2.t2
2.O7

3

r.948

L
3
1

1.919
r.879
1. 8 5 5

tt

t''"

12.21
12.2o003
2tl
202
103
t l.)

212
220
221
203
301
004
310
222
213
Jll

2.16
2.12
2.O7
2.03
('t sati 1.e43
1. 9 1 8
1.876
I .853

104
302
114
312
321223204
303(t.azz114

t.822

j r.aro3220051.797|.1.81s
1.793
|.760

400
104

J IJ

1.780
r.759
1. 7 1 2

lr.7r0t1.710

401
411
115

ABERNATHYITE. URANIT]M MINERAL OF THE METATORBERNITE

89

Trrl-n 3-(continued)
d1-eas)t.667

1.625dkatc)

224
402
330

|.69r
1r.667\1.667
1.662
1.662
r.646
1.641
1.624
1.620

JJI

323
304
420
412
205

1 .606
1.582

332
215
+21403422
413

fr.ss+

j 1.s8o,rr.J/y3

1.5r43t.482
I .458
1.421
t.372
1.359
1 .3001. 2 8 0| 261

J63115A

1, broad
1, broad

r.240

33

r.206

1|.r87

r.542
1.512
1. 5 0 8

1.212
1.198

torbernite group are listed in Table 4 for comparison. We are grateful toGabrielle Donnay, of the GeologicalSurvey, for the measurementof theT,lert' 4. Colrp,q.nrsoN ol Umrr-Cor,r DruBxsroNs or AsnnNA.rnvtto
Gnoup
wtrrt TrrosB or Orrrun Mnunnns ol rnr MorltonsnnNrrr
Mineral or compound
Abernathyite K(UOz) (AsOr) '4HzOSynthetic troegeriteH(uot(Asor)
4H:oSynthetic Na(UOz) (AsOr)' 4HrO
Synthetic NHa(UOr) (AsOn)' 4HzO
Meta-autunite I Ca(UOz)z(PODz.2i-6iE rO
Metatorbernite Cu(UOr)z(POr): 8HzOI Mrose.M. E.. 1953.
2 f)onnay, Gabrielle(oral communication).

on(A)7.16712

7. 2 r
6. 9 8
6. 9 5ro(A)9088808.70885
8.42
2x 8 . 7 0

Reference_l_t-1.J

M, E, THOMPSON, BLANCHE INGRAM, AND E. B. GROSS

lattice constants of abernathyite from Buerger precessionphotographs.
The constantsare given as follows: ao:7.!7 +0.01 A; co:9.08f 0.01 A;
space group PL/nmm (Drlh); cell contents 2 formula units K(UO|(AsOr)'4HrO. The calculateddensity is 3.74.
Beintema (1938) assignedmeta-autunite to the spacegroup P4f nmm,
but he had to postulate a statistical distribution of Ca over half thesymmetrically equivalent sites in the crystal structure in order to account for this high symmetry. Recently, G. Donnay (oral communication) found that this mineral and others in the group actually havelower symmetries as well as true cells which are multiples of Beintema'scell, so that the cations are in reality in ordered arrangement. On theother hand, her measurementsindicate that the true symmetry of abernathyite is PL/nmm with all the cation sitesoccupied by K ions, of which
there are twice as many as there are Ca ions in meta-autunite.
RTTnRENcES
BuNtnua, J. (1938), On the composition and the crystallization of autunite and the metaautunites: Rec,lravaur chim,, Pays-Bas, 57, 155.
Mnosr, M. E. (1953), Synthetic uranospinite: Am. Minerotr.,38, 1159.
Muruny, F. M. (1944), Geologic map of the Temple Mountain district, Union Mines Development Corp. (Unpublished map).
Monuscript

recei.vedJan. 21, 1955.