THE AMERICAN MINERALOGIST, VOL. 45, IANUARY-FEBRUARY' 1960

WEEKSITE, A NEW SILICATE FROM THE THOMAS RANGE, JUAB COUNTY, UTAHI W. F. OuTBRBRTDGE,1\{. H. Staetz, R. llbvnowtrz, awo A' M' Portnton, U. S. GeologicalSuraey;Washington, D' C', Demer, Colorailo,Washington, D. C., and Woshington D' C'

ABSTRACT

and Texas' Wyoming,- California, New Mexico, Mexico, Arizona, Weeksite is biaxial negative 2V:about 60o; dispersion r>v' strong; a:1'596' green, Z:o, yellovt green' The 0:1.603, t:1.606; X:b, colorless, Y:c, paie yellow measured specific gravity is about 4'1. A chemical a.ralysis of material from the Thomas Range showed: KzO 5.5,Na:O 0.7, A BaO 1.4, CaO 1.1, UO3 51..5,SiO: 33.6, lf{zO6.6, AhOr 0'6, COs 0'3; total 101'3/e' syn- (in part from thetic Na analogue of weeksite showed NazO 7.2,1JO352.0, SiO, 33'9, HrO wood) 8.1, C (from wood) 0.3; total 101.5!6' Weeksite is orthorhombic, pseudotetragonal; the space group is Pnnh-D*; -- a: t4.26 + 0.02 A, b: 35.88+ 0.10 A, c t4'20 + 0.02 A; aib:c: '3974:1:'3958' r-ray powder cell contents 16 [Kz(UO):(SirO6)3'4HrO]. The nine strongest lines of the (6), (5)' pattern of weeksiie are:7.11 (10), 5.57 (9), 8.98 (8), 3.55 (7), 3'30 (7),2'91 3'20 (9) (8) 2.37 (5), 2.28 (5); and those of the synthetic Na analogue arc 7 'Il (10), 5'57 ' 9'03 ' 3.56(7),3.30 (7), 2.94 (6),3.19 (5), 2.37 (5),2.28 (5).

h.IrnolucrroN ANDAcxNowrnoGMENTS Weeksite, a potassium uranyl silicate mineral, closely resemblesuran- ophane in phyiical appearance.It was first noted as an unknown and perhaps new mineral in 1950,when a uranium mineral from the east side of th. tho-as Range in western Utah gave an unidentified r-ray powder pattern. Since that time r-ray powder pattelns have indicated its pres- encein nine other localitiesin Arizona, California, 1\4exico,New Mexico, Pennsylvania, Texas, Utah, and Wyoming. Week.ite, in its known occurrences'is rare' very fine grained, and intimately intermixed with other minerals. For these reasons'it was not until 1955 that enoughof the material was collectedfor a complete chemical analysis. This material came from the east side of the Thomas Range.Although it was originally hoped to make a more thorough study of weeksite, correlating the chemical composition of this mineral with its physical and optical properties from a number of localities, the minute

1 Publication authorized by the Director, U' S. Geological Survey' 39 4I W. F, OUTERBRIDGE.ET AL.

quantities of this mineral found at most localities made such a compara- tive study impossible.

Thomas Range. These are compared with those of synthesized week- site and its sodium analogue. This new mineral is named for Dr. Alice D. Weeks of the U. S. Geo_ logical survey, who has studied and described many new uranium and vanadium minerals.Her report with Mary E. Thompson entitled, ,,rden- tification and occurrence of uranium and vanadium Minerals from the colorado Plateaus," (1954)is a major contribution and providesmineral- ogistsand geologistswith reliabledata for the recognitionof theseminerals. we gratefully acknowledgethe assistanceof many of our colleaguesin the u. S. Geologicalsurvey. These include samuel Rubenstein and

ergy commission for information on specimens from the Good will claim, Utah, and from near San Carlos,Mexico; to RussellHonea of the university of colorado for data on the mineral from the Mammoth mine, Texas; to T. C. McBurney for a specimenand data on the mineral from the coso Mountains, california; and to clifford Frondel of Harvard uni- versity for advice and encouragement. This investigation is part of the project of mineralogical investigations conducted by the u. s. Geologicalsurvey on behalf of the Division of Raw Materials of the U. S, Atomic Energy Commission.

OccunnBNcn weeksite has been identified from ten widely separatedlocalities. The type specimen of weeksite comesfrom the Autunite No. g claim, 4I WEEKSITE, A NEW UMNIUM SILICATE

and quartz in a dense,white ash matrix. to The weeksite occurs in numerous veinlets, from one thirty-second

or . sec. weeksite has also been found on the Good will claim in the NW I 42 W. F. OUTERBKIDGE,ET AL.

4) the lake dried up and an ash fall formed a white vitric tuff, 5) the re- gion was tilted gently to the west, and a north-trending fault developed along the east side of the district, and 6) uranium mineralization oc- curred. uranium minerals are found in two types of occurrenceson the Good will property: disseminatedin the tuffaceoussandstone and as re- placement in Iimestone cobbles in the conglomerate which overlies the sandstone.The only occurrencesof economicsignificance are those in the tufiaceous sandstone. Beta-, the chief ore mineral, fills nu- merous pore spacesin the sandstone. The only other uranium mineral

Frc. 1. Rosettes of weeksite enclosed by thin botryoidal bands of . East side of Thomas Range. X38. noted in this rock was schroeckingerite,which occurredin a few veinlets in one pit. weeksite occurs in the conglomerate, where it irregularry replaces parts of limestonepebbles or cobbles.rn pebblesover an inch in diameter weeksite is confined to an irregular outer layer as much as one-quarter of an inch thick, but in smaller pebblesit may also repracepart of the center.The pebblescontaining weeksite are erraticallyscattered through- out the conglomerate.weeksite occurs in extremely fine grains and is the only mineral replacing the limestone pebbles. No weeksite has been found in the uranium depositsin the underlying tufiaceoussandstone, and neither beta-uranophane nor schroeckingeritehas been found in the conglomerate. The uranium mineralization that formed the weeksite at the Autunite WEEKSITE, A NEW URANIUM SILICATE 43

No. 8 and the Good Will claimsis believedto have taken placeduring the last stagesof vulcanism (Pliocene)in the Thomas Range' It was during this period after the consolidationof most of the volcanic rocks that uranilerous fluorspar deposits were formed in the western part of the Thomas Range (Staatz and Osterwald,1956, p. t32) ' just Weeksite has also been found in eight other localities; 1) from above the Haiwee Reservoir in the Coso Mountains, California, where we identified it as a coating along fractures in granite associatedwith urano- phane and an unknown yellow uranium mineral on a sample submitted ty T. C. McBurney in 1955.This is the samelocality from which the new mineral haiweeitewas describedby McBurney and Murdoch (1959);2) in a sand- from the Jackpilemine, Laguna, New Mexico, whereit occurs stone-typedeposit; 3) from the Silver CIiff mine, near Lusk, Wyoming, whereit occursin calcareoussandstone with uranophane(A' D' Weeks, 1958,oral communication);4) from the Williams quarry' Easton, Penn- sylvania (Samuel Rubenstein, 1955, written communication), where it is found in fractures in the Precambrian Franklin limestone associated with thorian , thorogummite, uranophane,, and bolt- woodite(Montgomery,1957, p. 812-813);5) from the Red Rock district, Lassen county, california, where it is found in fractures in rhyolite (D.R.Ross, 1958,oral communication);6)from the dump of an aban- doned mercury mine, Chihuahua State, Mexico, 4] miles southwest of Lajitas, Texas, where il is associatedwith carnotite (E' B' Gross,1955, *.itt.n communication); 7) from the Mammoth mine near Presidio, Texas, where it lines cavities in a welded tuff (Russell llonea, 1958, oral communication); and 8) from the Red Knob claims, Muggins Moun- tains, Yuma county, Lrizona, where it is associatedwith opal, carnotite, vanadinite,, calcite,and azurite (W. I. Finch and M E' Thomp- son. 1957,oral communication).

Pnvsrcar- AND OPTTcALPRoPERTTES Weeksite at the Autunite No. 8 claim occurs as small spherulites of yellow radiating crystals. The crystals have a waxy to silky luster and structurally resemblewavellite (Fig. 1). Uranophaneand haiweeitehave the same habit and appearance, and it is virtually impossible to tell them apart megascoPicallY. weeksite is soft. It crushedsomewhat more easily than gypsum when a sample was ground for x-ray examination. An approximate specific g.unity of 4.1 was obtained by centrifuging grains of the mineral in warm ioncentrated Clerici solution. The specificgravity as calculated from the formula weight and the unit cell sizeis 4.02for 16[Kz(UOr)z(Sizor)a'4HzO per cell. The optical properties of weeksite and of uranophane are given in M W. F. OUTERBRIDGE,ET AL.

Table 1. weeksite is orthorhombic. The small acicular crystars are elongated parallel to the c axis and show two good prismatic cleavages. Some crystals are more bladed than acicular and are flattened on the (010) plane. Specimensof this mineral from an abandoned mercury mine in Mexico occur in flat plates. Like uranophane, weeksite is not fluo- rescentin either long or short wave ultraviolet light. The mean index of refraction of the synthetic sodium analogue is 1.58. The indices of re- fraction of weeksite are close to those of haiweeite, johannite and meta- autunite. Johannite differs from weeksite,however, in being biaxial posi- tive instead of biaxial negative, light green instead of yellow, and a

Tenrn 1. A CoMpanrsoN ol rnn Oprrcel PnopRnrrrs ol. WBnxsrrr .lNo UnaNopn.lrn

Index of Orientation Pleochroism Remarks refraction

Weeksitel X:b 1.596+.003 colorless biaxial (-) Y:c 1.603+.002pale yellow-green 2 V-50-60' (observed) z:a 1.606+.003yellow-green 2Y :66' (calculated) r > \', strong

Uranophane2 X/1a:2.8" 1.642-L645 colorless biaxial negative Ylc:10' r.665-L667 pale canary vellow 2 Y:32" z:b | .667-1.672canary yellow r{v, marked to extreme

I Autunite No. 8 claim on the east side of the Thomas Range, Utah. 2 Data from Larsen, E. S., Jr., Hess, F. L., and Schaller, W.T., 1926.

copper uranyl sulfate instead of a potassium uranyl silicate. Meta- autunite differs from weeksite in being generally crystallized in scaly aggregatesinstead of in fibrous rosettes, fluorescent instead of nonfluo- rescent, and arcalcium uranyl phosphate instead of a potassium uranyl silicate. Haiweeite difiers from weeksite in that it is fluorescent, crystal- lizes in the monoclinic system, and has a similar but distinctly different r-ray pattern, This pattern was a recurrent unknown under investiga- tion in the laboratories of the U. S. GeologicalSurvey.

CuBurcal Coupostrrow About 100 mg. of weeksitefrom the east side of the Thomas Range was purified for analysis. The mineral first was concentrated by crushing the rhyolite containing the uraniferous opal veinlets and making a neavy Iiquid separation of the powder. That portion of the mineral mixture WEEKSITE, A NEW URANIUM SILICATE 45 which sank in bromoform was further purified by scrubbing in an ultra- sonic generator and by passing it through a Frantz Isodynamic Separa- tor. The nonmagnetic portion from the separator contained predom- inantly weeksite and some opal and rutile. The impurities were picked out by hand.under the binocular microscope.The sample is estimated to have been entirely free of impurities. The methods employed in the chemical analysis were guided by quali- tative spectrographicanalyses of the samples(Table 2). Approximately 100 mg. of the naturally occurring mineral and 35 mg. of the synthetic Na analogueof the mineral were available for chemicalanalysis (Table

Terr-n2. Sppcrnocna.prrrcANlrvsrs or Wnxsrrn rnou AuruNrrn N"

Sample over 1016 | to 5/s 0.5 to l/6 o.I to 0.5/s o.05to 0.1/6

MHS-t-501 USi AI Ba Ca Na MHS-1-50' K (3%) Na (0.7%) G-1431(synthetic) USi NaBAI

I Based on a 1 mg. portion of the sample using method of Stich (1953); values given are tough approximations. Analyst: Katherine V. Hazel, U. S. Geological Survey' 2 Semiquantitative analysis for alkalies of a 10 mg. portion of the ignited residue re- maining after the CO: and HzO had been determined. Method of Waring and Annell (1953) was used. Analyst: Ilelen W. Worthing, U. S. Geological Survey. Figures are re- ported to the nearest number in the series 7, 3, 1.5, O.7, O.3,0.15, and 0'07' in per cent' These numbers represent mitlpoints of group data on a geometric scale. Comparisons of this type of semiquantitative results with data obtained by quantitative methods, either chemical or spectrographic, show that the assigned group includes the quantitative value about 60 per cent of the time.

3). There was not enoughof the syntheticK compoundfor chemicalanal- ysis. One fraction of the sample was used for the COz or C and total HzO determinations;a secondfraction of the samplefor theH2O-, SiOz insoluble in (1-|1) HNO3, SiOz soluble in (1*1) HNOa, UO3, BaO, AlzOa,and FezOadeterminations; and a third fraction of the samplefor the KzO, NazO, and CaO determinations.Micro- and semimicroproce- dures were used throughout. The first fraction of the sample was decomposedby ignition at 900" C' in a stream of oxygen. COzor C and total water were determined by use of a modified microcombustion train of the type used for the determina- tion of carbon and hydrogen in organic compounds. The second fraction of the sample was dried to constant weight at 110' + 5o C. and then boiled with ( 1* 1) HNOa until the insoluble material was completely white. Filter paper was used for the separation of the 46 I4T.F. OUTERBRIDGL,ET AL.

residue, which, after washing with dilute nitric acid, was ignited to con- stant weight at 850o C. Qualitative spectrographicanalysis of the ig_ nited residueshowed that siliconwas the onry major constituentpresent. The soluble silica was determined gravimetricaly by dehydration in a HNos solution. Aliquots of the filtrate from the soluble silica determina- tion were used for the UO3, BaO, AlrOa, and FezOadeterminations. UOr

Tenre 3. Cnnurcll ANarysrsor Naruner,Wmxsrrn awuIrs :--- I 2 MHS-1-50 G-143

SiOzinsolublcin 1*1 HNOr 33.0 32.O 32.79 33.77 33.1 SiOzsoluble in 1*1 HNOI 0.6 19 AlrOa 0.6 UOa JI..) 52.0 52.09 53.66 52.8 CaO 1.1 5.4 NarO 0.7 7.2 5.82 KzO 5.5 8.56 BaO 1.4 (- 0.3 (wood) COz 0.3 (totai) HrO 6.6 8.1(somefromrvood)6.56 6.75 8.7 HsOt* 5.5 62 HzO- 71 1.9 liezOr <0.1

Total 101.3 r01.5 100.00100.00 i00.0

1. g weeksite from the Autunite No. claim on the east side of the _rhomas l{anse. Robert Meyrowitz, ana"lyst. 2. Synthetic sodium analogue of weeksite. Robert Mevrowitz, analvst. 3. Kr(UOtr(SizOs)r. 4HzO. 4. Naz(UO)z(SrzOs):.4HzO. 5. Haiweeite, McBurney and Murdoch, 1959. " Calculatecl by dif{erence between total H:O ancl HzO-. was determined spectrophotometricallyby the ammonium thiocyanate procedure in an acetone-watermedium. Barium was separatedand de- termined as the sulfate. Aluminum was determined spectrophotometri- cally using aluminon. To avoid the interference due to uranium in the aluminon procedure, aluminum was separated from the uranium by use of the ion-exchangeresin Dowex 1X10 in a 9 molar HCI medium. rron was determined spectrophotometricallyby the o-phenanthrolinepro- cedure. WEEKSITE. A NEW URANIUM SILICATE 47

In the third fraction of the sample, potassium, sodium, and calcium were determined by flame photometry using aliquots of the filtrate re- sulting from the removal of the (1+1) HNOa insoluble material. The filtrate was compared to standard solutions containing approximately the same concentrationsof uranium, potassium,sodium, and calcium as were presentin the solution of the sample. Weeksiteis one of thosesilicates which, when treated with acid, yield a hard skeletonof silica. Murata (1943 and 1946)described this feature for certain common silicatesand notes that it is limited to some silicate structures,including SiO3chains, SiOr double chains, SizOssheets with but minor substitution of ferric iron for silicon, and three dimensional frameworks having an aluminum content less than the ratio of two aluminum atoms to three silicon atoms. The formula calculated from the chemical analyses (Table 3) is Kr(UOrr(SirOs)e'4HzO,but Na, Ca, and Ba and probably other metals can also substitute for K. The newly describedmineral haiweeiteis the calciumanalogue of weeksite,having the formula Ca(UOz)z(SirOs)s'5HzO (I{cBurney and Murdoch, 1959). In the synthetic sodium analogue (Table 3) sodium has completely substituted for potassium in the min- eral, yet its *-ray powder pattern is identical to that of the synthetic weeksite. Weeksite is the only uranyl silicate known besidesboltwoodite (Frondel and Ito, 1956) that containsan alkali as an essentialcation. Weeksite and the sodium analogueof weeksite were prepared syntheti- cally by Pommer by heating alkaline uranate solutions in sealed pyrex tubesat 150' C. for at leastthree days. The calculatedpressure inside the tubes was approximately 70 lbs./in.2. The conditions of synthesisare summarizedin Table 4. It shouldbe noted that the solutionsdid not con- tain silica; the glassof the tube, somewhatattacked by alkalinesolutions at the temperature of the experiment, was relied upon as a sourceof silica. The Na analogue of weeksite first appeared as a solid phase during an attempt to reduce a uranium-vanadium solution with wood at a high pH to form a mixture of uraninite and montroseite. The wood failed to act as reducingagent, probably becausethe pH was too high. More of thc compound was prepared by this method in order to test its reproduci- bility and to furnish a supply of the material for further study. After the chemical compositionof weeksitebecame known, weeksitewas synthe- sized successfullywithout the addition of vanadium. The use of wood was continued,however, because in other mineral synthesisexperiments (Pommer, 1958,unpublished laboratory data) wood appearedto act as a buffer in some solutions and promoted the formation of phases which otherwise did not precipitate. Finally a synthesisof the Na analogue without wood was successful.Part of the work then was repeatedto form 48 W. F. OUTERBRIDGE, ET AL.

the K phase. Several of the solutions contained sodium carbonate or potassium carbonate as a bufier. The conditions of formation of bolt- woodite and weeksiteare similar and co-precipitatedin sev- eral runs. The componentsof all the runs were identified by r-ray diffrac- tion.

'Ierln 4. Svwrnusrsor Wnaxsrrn .q.NnRor,treo Coui,ounns

, Molaritvof uran- Molarityo[va- B.l|"r.d Com- lH , Woo,l at ium (addedas nadium(adderl as acllusreo .ur- pound ,il}ii. 1,rn *"*"",.1.t".t uranylnitrate) vanadylsulfate) with bonale formedr

G-33 10.0 0.025 0.05 NaOH no yes a G-52 10.0 0.025 0.05 NaOH no ycs a G-53 10.0 0.025 0.05 NaOH no yes b G-55 10.0 0.025 0.05 NaOH no yes c G-143 11.2 0.05 NaOH yes yes c G-tffi tl .2 0.05 NaOH yes yes d G-163 1r.2 0.05 NaOH yes yes e G-r66 11.2 0.05 NaOH nonoc G-167 tl .2 0.05 KOI{ yes yes f G-r70 tr.2 0.05 KOH yes yes g G-174 rt.2 0.05 KOH nonog G-179Ir.2 0.05 KOH yes yes f G-182tt.2 0.05 KOH yes yes g G-18411 .2 0.05 KOH yes yes g G-187rl .2 0.0.5 KOH nonog G-18811.2 005 KOI{ nonos

a. Sodium analogue of weeksite but with slightly larger spacing of some lines. b. Sodium analogue of weeksite mired with boltwoodite Kz(UOz)z(SiOr)z(OH)z.5HsO). c. Sodium analogue of weeksite. d. Sodium analogue of weeksite plus some other unidentified compound represented by three dilTractionlines. e. Sodium analogue of weeksite, plus someother unidentified compound representedby two weak lines. f. Boltwoodite the dominant compound with iesseramounts of weeksite. g. Weeksite, 1 Cornpound identified by r-ray study by Daphne R. Ross.

X-R,c,v DrltnecrroN D.rr.q. The x-ray difiraction powder pattern of weeksite was one of the recur- rent unknown patterns in the r-ray laboratories of the GeologicalSurvey from 1950until the recentdetailed study. The pattern resemblesthe pat- terns of the uranophane group in a general way, but not in detail, and is similar to, but distinctly different from, that of haiweeite.No significant differences could be observed between the powder patterns of natural WEEKSITE, A NEW ARANIUM SILICATE 49

Tesm 5. X-Rlv Powonn Dlre ron N.lrunlr- AND SYNTHETTcWenxsrtn, Kz(UOz):(SirOr)3'4HzO, AND roR tnn SvNrrrntrc Na ANar'ocun, ColrPnnno wrtrr Hntweule : Weeksite: orthorhonrbic, a : 14.26+ 0.O2,b : 35.88+ 0.1 0, c 14.20+ 0.02 A ; space group, Pnnb-Dzn6

Measuredl

Calculated Synthetic Na Haiweeite Analogue

040 8.97 8 8.98 8.67 10 9.14 (8,200,002 I 7 .87) 2 8.05 200 /-lJ 10 7.tl 7.08 002 7.r0 4 7.05 (8,240,O42 1 6.17) 240 5.58 9 5.57 .).J/ 2 5.53 042 .)..x) 1 5.06 222 4.84 4.83 4.84 4 .85 + 4.9o 071 4.82 2ffi 4.58 Aa7 062,t7 | +-tl 4 4.58 4.60 4.56 301 4.51 080,103 4.49 3 4.48 322 3.86 o 4.42 262,223 3 .85 4 384 3 .84 3.84 z 3.82 091 3.84 -1 ??O 280 3.80 2 v.tr 082 3.79 400 J.J/ / J.JJ 3 .54 3.56 3 .54 004 282,303 3.35 4b 3.34 313 J.J4 044,44A,362 3.30 7 3.30 3.29 3 .30 3 .30 263 3.29 IM 3.22 2.ro.o 3.2r 3.20 3.r9 0.1o.2,4n2,M| 3.20 2O4,0.11.1 3.18 422,343 J.l+ 3.106 224,2.10.r,372 3.13 J.IJ 1.r0.2,273,292 3.t2

l Camera diameter, 114.6 mm; radiation, Cu/Ni, I CuKa:1'5418 A' Film cut-ofi, d> 13.0A; b:broad. 50 W. F. OUTERBRIDGE, ET AL

Taern 5 (continued)

Measuredl

Calculated Weeksite Synthetic Na Haiwecite Synthetic Analogue

d'n*r ut*t

432 3.08 234 3.07 3.06 460 3.06 093,064 3.05 442 3.00 244,0.12.0, 391, 461 2.99 2.99 2.99 164,193 2.98 210.2,363 2.92 4!.2 2.91 6 2.91 2.91 2.94 2.905 2.11.1,1.11.2,2542.90 ?,73,3.r0.1,392 2.81 3 2.80 2.79 2.81 2.8r 293,1.10.3 2.80 0.11.3, 3E3 2.69 + 2.69 2 2.62 1 3.r12 2.52 3 2.51 2.51 2.51 2 2,5r 2.rr.3,404,414 2.51 4 2.41 2.41 2.M s 2.37 z -.1t 2.37 2 2.39 5 2.28 228 2.28 2 2.28 4 2.24 2.24 )14 3 2.20 2.20 2.20 + 2.r7 4 2.r3 2.13 2.14 4 2.ll 2.t0 2.10 4 1.994 3 1.973 1.977 t.973 r.979 3 1.922 1.921 1.916 t.923 4 1.905 4 1.899 1.897 1 898 1 1.872 ; 1.8s4 1.854 2h 1.831 1.829 3 1.791 4 1778 1 781 + r.763 3b 1.741 I r.726 r.732 4 L689 1.686 plus additional lines,all with r<3 WEEKSITE,A NEW URANIUM SILICATE 51 wceksite,synthetic weeksite'and the synthesizedNa analogue,in spitc of the wide differencebetween the ionic radii of Na and K' Nor were there any differencesin the spacingor in the width of the lines betrveen roughly and gently ground specimensof the same sample' Powder pat- terns of samplesground in acetonedid not differ from the pattern of a

the true volume is eight times the volume of the pseudocelland therefore contains 16 formula units of weeksite.The spacegroup of the true cell is Pnnb - Dzn6. Calculated interplanar spacings based on the true cell and space group are given in Table 5, togethcr with observedd-spacings for natural and synthetic weeksite,the synthetic Na analogue,and haiweeite.

RnlnneNcrs Science, FnoNorL, Cttl'r.ono, eNn Ito, JtrN (1956), Boltwoodite, anerv uraniumsilicate: 124, no. 3228,931. (1926), minerals from Llnsrx, E. S., Jn., Hrss, F. L., nNn Scner,r-nn, W. T. Uranium Lusk, Wyomingl. Am. Mi,neral., ll' 155-164. mineral from McBunNBv, T. C., .tNo Munnocn, J (1959), Haiweeite, a new uranium California: Am. Mineral', 44, 839-843- MoNrcolrenv, Ancrun (1957), Three occurrencesof high thorian uraninile near Easton, Pennsylvania : Am. M iner al., 42, 804-820. gelatinize with acid: Munern, K. J. (1943), Internal structure of silicate minerals that

t955: U . S. GeoI SurtteyProJ. Papu 300' 131-136. grains: u. s. Geol'.survey Srrcn, J. N. (1953), Spectrographic iclentification of mineral Circ.234. W.nuNc, C. L., aNo ANNrlr., C. S. (1953), Semiquantitative spectrographic method for analysis of minerals, rocks and orcs"A.nal.,Chemistr"t,25. 117+-1179' 52 W. F, OUTERBRIDGE, ET AL.

I{ote add,ed,in proof Since this paper was prepared, Russell Honea (1959) has applied the unit cell parameters determined for weeksite by Joan Clarke by r-ray diffraction to material he calls gastunite. Honea's materiar is undoubtedly identical with weeksite. More recent study of the type gastunite, which was not available to Honea at the time his paper was published, shows that gastunite and haiweeite are probably the same material.

REr,ERxNcEs

Hannnr-alrar, Hnnsrnr ello Scrlnnrn, Arlnno (1951) Die Mineral- und Elementverge- sellschaftung des Zentralgneisgebietes von Badgastein (Hohe Tauren): Tschermahs Mitt.,2, 307-313. HoNn.r., Russrlr. M. (1959) New data on gastunite, an alkali uranyl silicate:,4 m. Minerot. 4,1047-1056.

Manuscri,pt receivedApril 23, 1959.