49

The C anadian M ine rala g is tVol. 34, pp. 49-54 (1996)

JENSENTTE, Gu3TeeOu.2H2O, A NEW MINERAL SPECIESFROM THE CENTENNIAL EUREKA MINE,TINTIC DISTRICT, JUAB COUNTY, UTAH1

ANDREWC. ROBERTSGeological Suwey of Canada, 601 Booth Street, Ottawa" Ontario KIA 0E8

JOELD. GRICEResearch Division, Canadint Musewt of Naure, Ottawa" Ontaria Kl P 6P4

I.F.F A. GROATDeparturcnt of Geolagical Sciences, University of British Cohanbia" 6339 Stores Roa4

Vancoaver, British Colwnbia V6T l7A

ALANJ. CRIDDLEDepanmet of Minerabgy, The Naural History Museun" Cromwell Roa[ Londan SW7 sBD, U.K.

ROBERTA. GAULTResearch Divisiou Canadian Masew, of Nature, Ottawa, Ontario KIP 6P4

RICHARD C. ERDU.S. Geolagical Survey, 345 Mitdlcfield Roa4 Mmln Parlc CaJifomia 94025, U.SA.

FITZA,RETH A. MOFFATTCanad.im. Conservaion Institwe, 1030 Innzs Road Ottawq Ontario KlA OMs

ABSTRA T

Jenserdte, ideally CurTetuOe.?HzO, is monoclinic, n1lry Q4), with rrnit-cell parameters refined from powder data:a 9.?A4Q), b 9.170Q), c 7.s%(l) A, p 102.32(3)", V 625.3(3) 43, a:b:c 1.@37:1:0.8270, Z = 4. The strongest six reflections ofthe X-ray powder-diffractionpattern ldn A(D(hl<t)l are: 6.428(l00xT0l,lr0),3.217(70)802),2.601,(N)Q02\2.530(50)Q30),2.144(35)Q3l) and 1.750(35X432). Ttre mineral is found on the dumps of the Centennial Eureka mine, Juab County, Utah,where it occurs as isolared crystals or as groups of crystals on drusy white quartz. Associated minerals are mcalpineite,xocomecatlite and rnnamed Cu(Mg,Cu"Fetn)2TefiO66H2O. Individual crystals of jensenite are subhedral to euhedral, andform simple rhombs thal are nearly equanl Some crystals are slightly elongate [101], with a length+o-width ratio up to 2:1. Thelargest crystal is approximately 0.4 mm in size; the average size is between 0.1 and 0.2 mm. Cleavage { 101} fair. Forms are:{1-01}major;{110}medium;{100}minor;{301},{201}, {2tr/3]t,{1U2},{010}verysmall.Themineralistranspaxent,emeraldgreen, with a less intense streak of the same color and an uneven fracture. Jensenite is adamantine, brifile and nonfluorescent;H (Mohs) !-!; ff (czlc.) 4.78 for the idealized formula, 4.76 g/cm3 for the empirical formula- In a polished section, jensenite isvery weakly bireflectant and nonpleocbroic. In reflected plane-polarized light in air, it is a nondescript grey, and in oil, it is amuch darker grey in color with a brownish tint, with ubiquitous bright green intemal reflections. Anisotropy is not detectable.Measured values of reflectance, in air and in oil, me tabulated. Electron-microprobe analy$es yielded CUO 50.91, Z^O 0.31,TeO3 38.91, H2O (calc.) [8.00], total [98.L37wLVo.The empirical formul4 derived from crystal-strucf[e analysis and electon-microprobe analyses, is (Cn2e{n'r)n.ilefoQ'62.03H2o, based on O = 8. The mineral name honors Martin C. Jensen,Reno, Nevafu who discovered the mineral.

Keyvords: jerl,rerllts. new mineral species, tricopper tellurate dihydrate, X-ray data" electron-microprobe data, reflectance d4tqCentennial Eureka mine, Iuab County, Utah.

I Geological Survey of Canada contribution number 68094.

50 TTIE CANADIAN MINERALOGIST

Somaans

La jensenite, de composition id6ale CurTeeO6.2H2o, est 6e1q'clinique, P21ln (14), et possbde les paramblres r6ticulairessuivants, affin€s d partir des donndes de dicfraction X obtenues sur poudre: a 9.2MQ), b 9.170Q), c 7 .5M(1) A, P 102,32(3)" ,V 625.3(3) Ar , a:b:c 1.0037: 1 :0.8270 , Z = 4. L,es six raies les plus intenses du clich6 de ditraction X ld en A(0(ftt41 sont:6.428(100XT01,110),3.217QO)802),2.601(40)(202), 2.530(s0X230),2.t44QrA3D er 1.750(3s)(432). La jensenite a dt6d6couverte sur les amas de rebus h la mine Centennial Eurek4 dans le comtf de Juab, au Utab, et se presente en cristaux isol6sou en groupes de cristaux sur du quartz laiteux tapissant une cavit6. Lui sont associ6s mcalpin6ite, xocomecatlite, et un min6ralsans nom, Cu(Mg,CuFeZn)2TetuO6.6H2O. I€s cristaux individuels sont subidiomorphes h idiomorphes, et se prdsentent enrhombobdres simples presque 6quidimensionnels. Certains cristaux sont l6gdrement allong6s selon [01], avec un rapport delongueur i largeur de 2;l,Laraille maximale est de 0.4 mm, mais les cristaux sont entre 0.1 et 0.2 mm, en g6n6ral. lr clivage{101} estconvenable; lesformes sont: {T01} majeur, {110} moyen, {100} nineur, et {301}, {201}, {203}, {T02}, {010}minuscules. Ir mindral est transparent, vert 6meraude, ayec une rayure de la mdme couleur mais moins intense. La cassure estin6gale et l'6clat, adamantin. Lajensenite est cassante et non fluorescente. La duret6 de Mohs est enffe 3 et 4. l,a densit6 calcul6eest 4.78 pour la formule id6ale, et 4.76 pour la formule empirique. Dans une section polie, la jensenite est trbs faiblementbirdflecta:rte et non pl6ocbro'fque. Dans la lumidre r6fl6chie polarisde, dans I'air, elle est gris ordinaire, et dans thuile, elledevient beaucoup plus fonc6e avec un tein brunatre et de multiples r6flexions internes vert brillant. Nous ne d6celons aucuneanisotropie. Nous documentons la rdflectance, dans I'air et dans lhuile. lrs analyses d la microsonde 6lectronique ont doundCUO 50.91, ZnO 0.31, TeO3 38.91, H2O (calc.) [8.00], total[98.13]Vo (poids). Ia formule empirique, ddrivde des r6sultats d'uneanalyse de la structure cristalline et d'analyses chimiques i la microsonde 6lectronique, est (Cur.rrZq.0rD.%Tefbtoj. s7.2.03H2Opour huit atomes d'oxygbne. Ir mindral honore Martin C. Jensen, de Reno, Nevada, qui en fait la ddcouverte.

(Iraduit par la R6daction)

Mots-cl6s: jensenrte, nouvelle espdce min6rale, tetlurate bihydrat6 de cuivre, donn6es de diffraction X, donndes de microsonde6lectronique, donn&s de r6flectance, nine Centennial Eureka, comt6 de Juab, Utah.

huxouucnoll

Jensenite, ideally Cu3TeGO6zHrO, is a newlyrecognized mineral species tlat was first encounteredduring megascopic examination, scanning electronenergy-dispersion study and routine X-ray powder-ditfraction characterization of a suite of secondaryCu- andTe-bearing minerals. This suite of samFles wascollected in July 1992 from the mineralized dumpsadjacent to the Centennial Eureka mine, Tintic district,Juab County, Utah. This mineral is the third of at leasteight new secondary Cu- and Te-bearing phases thatwill eventually be characterized; it was glven thedesignation 1mknown no. 2" in Matty et al. (1993),who described the primary and secondary mineralsfound at the Centennial Eureka mine.

The mineral is named jensenite in honor of Mr.Maxtin C. Jensen (1959- ) of Reno, Nevada who firstcollected and subsequently recognized this species aspotential new mineral. Mr. Jensen, an avid mineralcolector and noted scanning elecfion-microprobespecialist, has coordinated numerous mineralogicalstudies of mines and prospects throughout the westernUnited States, in particular Utah and Nevada. Themineral and mineral name have been approved bythe Commission on New Minerals and Mineral Names,I.M.A. Holotype material, consisting of four specimensand eleven single-crystal mounts, is housed in theSystematic Reference Series of the National MineralCollection at the Geological Survey of Canada,Ottawa, Ontario under catalogue number NMC 67424.

OccunnnNcs AND AssocIArD Mnlmar,s

Jensenite has been identified on at least twelvespecimens collected from the dumps of the CentennialEureka mine, Tintic dishict, Juab County, Utah (at.39o56'38'T.{, long. ll2o7'1,8\I). This copper, gold andsilver property, worked primarily from 1876 to 1927,was formerly the most productive and profitabledeposit in the district. The immense dumps ef fts minswere largely removed and processed for their low-grade concentrations of gold in late 1991. At this time,a wide variety of mineralized samples were exposed,including several boulders that contain tle newCu- and Te-bearing assemblages. Jensenite wasobserved in several of these boulders, but must beconsidered very rare; only about 10 mg of the mineralis presently known. On the holotype material, themineral is found as isolated crystals or groups ofcrystals that are perched otr drusy white to colorlessquartz. Associated minerals are thin lime-green stainsand dark green-black microspherules of mcalpineite@oberts et al. 1994), green nodules of xocomecatliteand pale yeUow transparent hexagonal plates ofunnamed cu(Mg,cu,Fe,7n)2TecO66H20 (desiguatedas UKCE-10). Additional Cu- and Te-bearingsecondary minerals that have been identified by X-raypowder-diffraction methods on similar specimensinclude cesbronite, frankhawthomeite (Roberts ar a/.1995, Grice & Roberts 1995), dugganile, quetzal-coatlite and four additional unnamed Cu- and Te-bearing phases currently under investigation.

JENSEMTE. A NEW SPECIES FROM UTAH 5 1

Additional information regarding the geology andmineralogy of the Centennial Eureka mine can befound in Marty et al. (L993). Jensenite is a secondarymineral that formed from the breakdown of primaryCu- and Te-bearing sulfides.

Pnvsrcer PnopsRTEs

Jensenite crystals are emerald green and transparent;the streak is the same color but less intense relative totle uncrushed material. The mineral is brittle,possesses an uneven fractule and au adamantine lusler,and is nonfluorescent under both long- and short-waveultraviolet radiation. The density could not bemeasured owing to the size of available specimens anddearth ofmaterial. The calculaled density based on theempirical formula is 4.76 g/cm3; that based onthe idealized formula is 4.78 g/cm3. The Mohshardness is estimated to be 3-4.

CnvsurMonpgorcv

Jensenite occurs on drusy quartz as isolated singlecrystals or as groupings of several crystals. Individual

FIGs. 1A, B. SEM photomicrographs of nearly euhedralcrystals of jensenite showing well-developed {T01} and{110} forms. Associated minerals are mcalpineite(spherules) and quartz (matrix). Scale bars: 10 [m.

crystals are subhedral to euhedral, and consist ofsimple rhombs that are nearly equant. Some crystalsare slightly elongate [101], with a length-to-width ratioup to 2:1. There is a fah {TOIJ cleavage. SEMphotomicrographs of several individual crystals,scattered on quartz and associated with mcalpineite,are lnesented in Figures 1A and 1B. The largest knowncrystal is approximately 0.4 mm in longest dimension,but the average size of the crystals is between 0.1 and0.2 mm. The observed forms, measured with a two-circle optical goniometer and supported by X-raysingle-crystal studies, are: major { 101} (ortho-pinacoid); medium {110} (prism);_minor {100}; verysmall {301}, l20L}, l2o3l, {lo2l, and_{010}.Interestingly, the forms {100}, {301}, and {102} allgive a blue-colored signal on the goniometer; thereason for this is unclear at this time. Twinning was notfound in X-ray single-crystal studies; however,megascopic examination ofjensenite in sin onrnneralspecimens shows some interpenetrating crystals thatmay possess a twin plane.

X-Rev CnYsrar.rccRAPIrY

Two crystals of jensenite were examined by single-crystal precession methods employing Zr-filtered Moradiation. One was mounted such that 101*, and theother such that 101*, is parallel to the dial axis.Precession films indicate monoclinic symmety, audsystematic absences (ft01 with h + I + 2n and 0k0 withk*2n) dictate that the space group is uniquely deter-mined as Y2yln (L4). Crystal-stucture analysis (Griceet al. 1996) has confirmed that this is the correct space-group. The rcfinsd unit-cell parameters, a 9.204(2),-u g.[totz), c 7.584(r) 4,, P toz.tz(z)", v 62s3Q) 43,a;bic = 1.0037:.l:0.8270, and Z = 4, are based on thed values^ of 24 X-ray powder lines between 3.896 and1.317 A for which unambiguous indexing waspossible, based on visual inspection of precessionsingle-crystat films. All reflections down io 1.28 Lwere visually examined on the precession filns.A firlly indexed powder pattem is presented in Table 1.The powder data are unique and bear no resemblanceto any other inorganic or mineral phase listed in thePowder Dffiaction File.

Orncer, PnoPsRTFs

The polished section previously used for electron-microprobe analyses was buffed with a slurry ofaluminum oxide in distilled water on Pellon cloth toexpose the fragment of jensenite for optical investi-gation. This fragrnent turned out to be fractured; thelargest individual fragment is 20 pm in maximumdimension.

In polished section, 66s mineral is very weaklybireflectant and nonpleochroic. In plane-polarizedreflected light jensenile is a nondescript grey, but is a

52 TTIE CANADIAN MINERALOGIST

35 2.t44s 2.u283 1.9t5

20 1.94630 1.8533 t:f79

35 1.7505 tJ20

'5 tJt2

3b t.63820 1.60920 l.5EE

5 lSU

30 t.527

r00l 03

30

l0b

l 020

5

105

5

1.507

t.447t.463t.436t.416t.399l38 tt.3461.3t7

I J

4050t 030

30

33

TABIJ I. X-RAY POVDR-DIFFRAC.IIOI\I DATA FOR JE{SENIIE

,lest. dAmeas. dAcelc. hkr ,fesl dAnru. d&a\c. hH

The largest area of jensenite was used for ameasurement ofreflectance; the procedures and equip-ment used were as described by Criddle et al. (L983).The x40 dry and immersion objectives (adjusted toprovide effective numerical apertures of 0.26) werefound to provide insfficient flux of reflected light forretable measurement at lower wavelengths, and hencethe tabulated data (Table 2) omit air and oilreflectances at 400 nm and oil reflectances at 420 and/,5 nr:r'. Application of the procedures recommendedby Embrey & Criddle (1978) for the evaluation of thereliability of measured reflectance data proves thatthe values measured in oil, particularly those for mR2,are the least reliable ofthe four data-sets. and that thisis a consequence of an unavoidable contribution fromintemal reflections (as a diffrrse component) to thespecular reflectance of the mineral. Jensenite is closeto being optically isotropic; however, small butmeasurable differences, dependent on optical orienta-tion, were detected photometrically, thus conformingwith its monoclinic symmety. The reflectance spechaare compared with those of mcalpineite (from which itdiffers appreciably) in Figure 2. Tbe indices ofrefraction of jensenite, calculated from tle morereliable reflectances in air at 590 nm (assuming fr = 0)ne l.9l-1..92 (those incorporating the oil reflectancesin the Koenigsberger equations are 1.87-1.89, yetanother indication that the values in oil are somewhatsuspect).

10

$a

6

4

2

450 500 550

)"nm

Ftc. 2. Reflectance spectra ofjensenite measured in air andin oil (if2 = 1.515) and compared with mcalpineite.

6.428 |:frl5363 5.7635293 52654.s23 4.523

4.0854.O37

3.896 3.8993.73E 3J33

3.444

321'7 32t63.129 3.t24

3.0vt'vzd 3.016

2.8942.887

2'6t6 2-a8.2.461

2.639 2.6352.il1 2.6002.s30 2.5282.434 2.4332357 2.358

22622248

2219 2212.t9t 2.190

l 0 lil00 l linl l l120210a li2rit2tzl2u2i2lir2tt2130intti l l131202x0i l30322240014004r

20

l 5l 0l 5l 53l 0t 525

2.145 i3l2.024 1231.986 4l tt.946 I331.852 0041.780 051l.?50 432't.7/2. 2241.703 3131.641 5l It.636 524l.6oi 4ul.58r 234r.566 443t.s62 U2t.524 0601.527 4321.508 333r.io6 fu2t.497 i6lt.4& 511t.43i 5331.415 234IJ98 l l5rjro 1s2t346 630t317 2A

114.6 m Debyesdfiq povdrr @ mployilg Ni-frlud & radlado (lG fa alj4l78 A). I@siri6 6t'mred viM!$ b = bmad lire. Nd @ected tu shiDkage edm idma.l sdrd lsd" ttu d @ a92&4, b gJm, c 758y'. LB w232",

much darker grey, though with a brownish tint, ifimmersed in oil (Np = 1.515). Bright green internalreflections occur at the grain boundaries. These 'Tlood"

the mineral, when it is observed between crossedpolars, and effectively mask any anisotropy (if, indeed,it is present). Qualitatively, it would be very dfficult todistinguish jensenite from another recently describedcopper teilurate, mcalpineite @oberts et aI. 1994).

TABII2. RBI.;FCTANCE DATA AND @LoR VALIJESFOR JENSB{ITE

\tu R, R, bR' tuR, ltn R' R, ^R, ^R,

5@5805E9

l.7t 1.93 600t.61 1.95 00tJz t.w 640t.69 t.97 6s01.68 1.97 6601.65 r.90 6801.63 1.88 700

Color Valu6

ClEnlmi@tA:

16

14

12

10.15 10 .39.9 10.09.8 9.99.6 9.89.4 9.6925 9.49.15 9.49.15 9.39.0 929.1 92

400420 ll.0 11.3440 10.8 lr24ffi 10.7 l l. l470 10.7 l l.0480 10.7 I 1.05m 10.7 10.8520 10.6 10.7540 10.4 r0.5546 10.4 10.4

1.59 1.80l.5t 1.68t.41 t.621.40 1.551.31 l.4lt24 t28123 t30123 1.30t21 t28r22 t27

CIE lllminqnt C:

tl3/o

|'a

P,o/o

0.435 0.436 0.423 0.418 x 0299 0298 0290 028'l0.,$8 0.406 0.412 0.416 / 03ll 0J08 0.310 031410.0 10.1 1.51 1.70 lilo l0.l 10.3 1.56 1.77496 49t 498 5W 1,, 485 492 4ffi 4902.9 2.9 5.6 6.8 P.o/o 4.6 52 8.0 8.9

7006506000 L400

for&n,.rr ',1.515

JENSEI\TTE. A NEW SPECIFJ FROM UTAH 53

CHHVtr.STRY

Crystals of jensenite were analyzed with a JEOL733 elechon microprobe using Tracor Northern 5500and 5600 automation. The wavelength-dispersionmode was used. Data reduction was done with aconventional ZAF routine in the Tracor NorthemTASK series of programs. The conditions were asfollows: operating voltage 15 kV, beam cuneil 20 nA,and beam 20 pm in diameter. Data for the sample werecollected for 25 seconds or 05OVo precision, whicheverwas obtained first" and for the standards. 50 secondsor 0.25Vo precision, whichever was obtained first. Al00-second energy-dispersion scan indicated that noelemetrt$ w:r'thZ> 8 other than those reported here arepresent. The following standards were employed:natural cuprite (C\rKcl), syntletic ZnSeO3 QnIa) ndsynthetic Fe3+TqO5(Otf (mackayite) (Ielo). Thevalence states for both Cu and Te. as well as thenumber of O atoms, were determined by crystal-stucture analysis (G,rice et al. 1996) prior to finalinterpretation of the elecfron-microprobe results. Thepaucity of pure uncontaminated material preventedthe quantitative determination of HrO by classicalmethods. However, its presence as bonded H2O wasconfirmed by both crystal-structure analysis and apowder infrared-absorption study; the formula wastherefore calculated to give 2H2O. T\e average resultoftwo analyses gave CuO 50.91 (range 50.89-50.92),ZnO 0.3L (range 0.31-0.31), TeO3 38.91 (range38.90-38.91), H2O [8.00], total [98.13] wt.7o. Wirh

O = 8, the empirical formula for this tricopper telluraledihydrate is (Cn .s2Zno.oz):z.s4Tef,*orO s.si'2.o3Hzo.The ideal formula" Cu3TeeO6'2HrO, requires CuO53.00, TeO3 39.00, H2O 8.00, total 100.00 wt.7o. Thisis yet another example of the use of crystal-structureanalysis in order to determine the precise chemicalformula of a complex mineral species (Hawthome &Grice 1990).

The Gladstone-Dale constants of Mandarino (1981)and the oxide proportions determined from theelectron-microprobe data and from the crystal sffucturelead to K. values of 0.185 and 0.184, respectively. Kp,calculated using the ayerage index of refractiot, 1.92,and the calculated density derived from the empiricalformula, is 0.194; for the same average index ofrefraction and the calculated density derived from theidealized formul4 Kpis0.l92. The compatibility indexis -{.M8 for the empirical formula and -0.043 for theidealized formula, indicating good compatibility(Mandarino 1981) between the physical and chemicaldat^.

Nrnenno SPEcIRoscoPY

The infrared specfrum of jensenite was obtainedu5ing a Specta-Tech IR-Plan infrared microscopeinterfaced to a Bomem Mchelson MB-120 Fourier-transform infrared spectrometer, which utilizes a0.25 mm liquid-ninogen-cooled mercury cadmiumtelluride detector. A small amount of the pure mineralwas mounted in a diamond-anvil microsample cello

6

E

gF

Wavenumber (crnr)

Ftc. 3. Intared-absorption spechum of jensenite.

54 THE CANADIAN MINERALOGIST

then pressure was applied to crush the mineral andcause it to spread as a randomly oriented powder; aftercrushing, the pressure was released. The diamond cellwas then positioned in the microscope accessory, audthe powdered sample masked, so as to isolate a circulararea measuring 100 pn in diameter and between I and5 p"rn in uniform thickness. Two hundred scans werecollected and co-added at 4 cm-l resolution, from700 to 4000 cm-r. The ffansmittance spectrum (Fig. 3)was produced by taking the ratio of the single-beamspectrum of the specimen in the diamond-anvil cellagainst a single-beam spectrum of the empty diamondanvil cell collected with the same parameters. Thespectrum shows a major band, centered on 3220 cm-[,which is due to O-H stretching and confirms thepresence of structurally bound HrO. The rather sharppeaks at 2928 and2857 cm-l, and probably the peak atL742 cnrl, are most likely aliphatic C-H stetchingvibrations due to a contaminant such as grease. Greasewas used on the tip of a needle to facilitate transfer ofthe very small grains to the diamond-anvil micro-sample cell.

Rnerrousrm ro KNowN SpBors

Jensenite is the second confirmed copper telluratehydrate known in nature. The fint is mcalpineite,CurTeOu.HrO @oberts et al. 1994). There are nohydrated synthetic compounds listed in the PowderDiffraction File.

Xocomecatlite, Cu3TeeO4(OH)n, originally de-scribed by Williams (1975), has the same Cu:Te ratioand the same number of O atoms. The possibilitycertainly exisa that jensenite and xocomecatlite arepolymorphs. Unfortunately, this cannot be determinedat present; neither the type locality, the Bambollitamine, Moctezuma, Sonor4 Mexico, northe CentenniatEureka mins pl6yide xocomecatlite material that issuitable for crystal-structure analysis.

Acrc{owr-encExvm\Ts

The authors thankMartin C. Jensen @eno, Nevada),who generously provided the jensenite-bearing mineralspecimens for study and who also supplied the SEMphotomicrographs reproduced in Figures 1A and 18.The autlors also thank Drs. A R. Kanpl W.B.Simmons, Jr., A.U. Falster and R.F. Martin for criticalp2dings of the manu5gripl.

Rmmmvcrs

CRTDDLE, A.J., Srent-sv, C.J., CltrsHou\4, J.E. & FErR, E.E.(1983): Henryite, a new copper-silver telluride ftomBisbee, Arizona. BulL Mindral lM,5ll-SL1 .

Eil4BREy, P.G. & Cnnoue, A.J. (1978): Error problems in thetwo-media method of deriving the optical constants z and& from measured reflectances. Arz. Mineral. 63, 853-862.

Grucs, J.D., Gnolr, L.A. & Rosmrs, A.C. (1996): Jensenite,a cupric tellurate framework structure with two coordina-tions of copper. Can Mineral. 34, 55-59.

& Rosm.rs, A.C. (1995): Frankhawthomeite, aunique HCP franework stucture of a cupric telurate.Can. Mine ral. 33. il9 -653.

HAwTHoRNE, F.C. & Gnrcs, J.D. (1990): Crystal-structureanalysis as a chemical analytical method: application tolight elements. Can. Mircral.2l, 693-702.

MANDARnTo, J.A. (198 1): The Gladstone-Dale relationship.IV. The compatibility concept and its application. CanMinzral.19,441450.

MARry, J., Jwsw, M.C. & Ronnnrs, A.C. (1993): Mineralsof the Centennial Eureka mine, Tintic disfict, EurekaUtah. Rocts & Mirwrals 68" 406416.

RoBs.rs, A.C., ERcrr, T.S., Cnnple, A.J., Jorrs, G.C.,Wu,mus, R.S., Cuns'ror, F.E., tr & JB{SB{, M.C.(1994): Mcalpineite, Cu3TeO6'H2O, a new mineral fromthe McAlpine mine, Tirolumne County, California andfrom the Centennial Eureka mine, Juab County, Utah.Mineral. Mag. 58, 417 424.

Gruce, J.D., CnooLE, A.J., Jwsn, M.C., IIARRIS,D.C. & Morparr, E.A. (1995): Frankhawthorneite,Cu2TetuO4(OH) 2, a new mineral species from theCentennial Eureka mine, Tintic District, Juab County,Utah. Can, Minera]. 33, ill-@1,

WtrrAMs, S.A. (1975): Xocomecatlite, Cu3TeOo(OlI1n, andtlalocite, CuleZn6(TeOf (TeO)2CI(OII)25'27H2O, trrtonew minerals from Moctezum4 Sonora, Mexico. Mineral.Mag.40,221-226.

Receiyed March 14, 1995, reviseil manuscript acceptedMay24,1995.