American Mineralogist, Volume 6E, pages 245-254, 1983

Orickite and coyoteite,two new sulfide minerals from Coyote Peak, Humboldt County, California

Rrcneno C. Eno eNn Genall K. CzeuaNsrie U. S. Geological Survey Menlo Park, California 94025

Abstract

Orickite and coyoteite occur with rare alkali sulfidesin a mafic alkalic diatreme near Orick, Humboldt County, California. Both minerals are very rare, and only a few milligrams of each have been found. Orickite,Na,KrCuse5Fer.ooSz.zHzO (x,y < 0.03,z < 0.5),is hexagonal;a:3.695, c : 6.164 (both t0.0lA); D = 4.212g cm-3 forZ:4. The six strongestlines in the X-ray diffraction powder pattern are [d in A, t, (*ttt):3.08, 100,(002); 3.20 90, (100);2.84,60, (l0l); 1.73,55, (103);1.583,30, (ll2);2.20, 15,(102). The mineralis brassyellow and opaque, weakly pleochroic, but strongly anisotropic (from grayish brown to grayish blue) in reflected light. Orickite is compositionally near iron-rich chalcopyrite, but the mineral may be related to synthetic chalcogenideshaving a distorted wurtzite-\2[I) structure. Coyoteite, NaFe3S5.2H2O,is triclinic, Pl or Pl; a : 7.409(8),b : 9.881(6),c = 6.441(3)A,a:100'25(3)',F=104"37(5)',y=81"29(5)':D=2.879ecm-3forZ=2.Thesix strongestlines in the powder patter! are: 5.12,100,(lll);7.13,90,(100);3.028,80,(220); 3.08O,70,(OO2);9.6,60,(010);5.60,60,(01l). Coyoteite is black and opaque;in reflectedlight it is pale brownish gray, faintly pleochroic, and strongly anisotropic (from gray to dull golden orange). The mineral is unstable under normal atmosphericconditions.

Introduction Peak, which also gives its name to the U. S. Geo- Several unusual minerals have been found in a logical Survey l5-minute quadrangle map of the mafic alkalic diatreme at Coyote Peak near Orick, area. Both namesand minerals have been approved Humboldt County, California. Previous papers by the IMA Commission on New Minerals and have introduced the minerals erdite, NaFeS2.2H2O Mineral Names. We emphasize the rarity of these (Czamanskeet al., 1980;Konnert and Evans, 1980), two new minerals;our study is basedon only a few bartonite,IQFezrSzo(S,Cl) (Czamanske e/ al., l98l. grains of each found in several specimens. Our Evans and Clark, 1981), , K6Na(Fe, studied holotype material will be deposited at the (National Cu,Ni)2aS26Cl,and rasvumite, FKe2S3 (Cza- SmithsonianInstitution Museumof Natu- manske et al., 1979),also found at this locality. ral History), Washington,D. C., and, barring new Here we introduce two new minerals: orickite, discoveries. we have no other material to distribute for scientific studies. This is particularly regTettable Na"KrCuFeSz.zHzOlx,y I 0.03, z < 0.51, and coyoteite,NaFe3S5.2HzO. In additionto these,sev- in the case of orickite as it has interesting relations eral as yet undescribed, hydrated, Na-Fe and Na- with chalcopyrite, wurtzite, and some synthetic Cu-Fe sulfides are present at Coyote Peak. These chalcogenideshaving a distorted wurtzite structure (Schiifer alkali-bearing sulfides are geologically ephemeral and Nitsche, 1974). and are extremely rare in their occurrence. The only other locality where some of these samealkali Occurrenceand paragenesis sulfides have been found is the Khibina massif on Both minerals occur in small (l-4 cm diameter) the Kola Peninsula,USSR (Chukhrov, 1978;Cza- "pegmatitic" clots, thought to have crystallized manskeet al., 1979). late in the consolidation of the Coyote Peak magma. Orickite (or'ik-it) is named for the small coastal These clots are enriched in Na, K, and H2O relative lumbering town nearest the locality. Coyoteite (ki- to their host rocks and characteristically contain o'ti-it) is named for the local prominence, Coyote phlogopite,schorlomite, aegirine, sodalite, cancrin- 0003-004)v83/0l 02-0245$02.00 245 26 ERD AND CZAMANSKE: ORICKITE AND COYOTEITE ite (vishnevite),pectolite, natrolite, ,and, Table l. Electron-microprobeanalysis of orickite very rarely, calcite. Associated sulfidesare pyrrho- ht Z* Range Recalc. Atmic tite (6l.2wt.Vo Fe,39.l wt.%oS) and one or more of to 1002 ratio (S=2) the alkali-iron sulfidesdjerfisherite, rasvumite, bar- NA 0.4 ( 0.li- 0.53) 0.4 0.03 tonite, and erdite. K 0.2 ( 0.0s- 0.2s) 0,? 0.01 Coyoteite and orickite are rarer and finer grained Cu 31.7 (30.8-32.7) 32.7 0.95 -32.2) than theseassociated sulfides; coyoteite was found Fe 31.0 (30.0 32.O 1.06 s 33,b (33.1-34.4) 34.7 2.00 only in specimen77-CYP-134, and orickite only in ToraI 100.0 specimens77-CYP-134 and 78-CYP-250.The maxi- mum observeddimension for either mineral is 0.4 Average of six grains analyzeq in tro laboratories at 15 and Z0 k[/ using CUFeSZas the stanoard. Six to ten spots per grain xere mm; many grains of orickite are small laths of only occuDleo. approximately 15 x 150 pm. Although grains of ooes not include 1.5-5,1 weight percent (detected qualitatively by analysis wrth a TAP crystai). Sought for, but orickite have been found within clear sodalite (Fig. not detected: Al, Ca, Cl, Co, Mg, and Ni, 1)and one calcitecrystal, the two mineralstypically occur as isolated individuals within a nondescript dark-gray matrix of complex mineralogy and cellu- lar to lamellar texture. This matrix has the aspectof Park, California, using the theoretical data-reduc- leachingand depletion. Attempts to define better tion program FRAME(Yakowitz et al., 1973);stan- the mineralogy of the matrix through microprobe dards and operating conditions are noted in Tables I and X-ray studies suggest that very fine-grained and 6. All the orickite analyzedwas from specimen pyrite, hematite, native sulfur, and a complex ferric 77-CYP-134 from which several polished-section sulfate(?)phase may all be present, presumably as mounts were prepared. Orickite in one of these alteration products. mounts was analyzed both in Menlo Park and in No relations have been observedthat place coyo- Ottawa, Canada (by J.H. G. Laflamme of the teite and orickite within the parageneticsequence of Canada Centre for Mineral and Energy Technolo- the other sulfidephases. On the basisof the compo- gy). Table I incorporates both sets of data, for sition of coyoteite and its occurrence (solely within which mean values differ by less than one weight what appears to be a late-formed unstable matrix), percent. From the averagedanalysis, the formula of coyoteite was probably among the last sulfide orickite is Na"KrCus.e5Fe1.6652'ZH2O,where -r and phasesto form. y are both lessthan 0.03and z is lessthan 0.5. This the alkalis and water, is Orickite composition, neglecting identical with that of an iron-rich chalcopyrite (Ta- Chemistry ble 2). Hall (1975)showed that the mineralsof the Both orickite and coyoteite were analyzed with chalcopyrite seriesare metal-rich rather than sulfur the enr EMX-sM electron microprobe in Menlo poor. Until the of orickite is known, we shall follow Hall in basing the atomic ratios on two atoms of sulfur. Before further discus- sion of the chemical composition and relations of orickite, however,we first considerthe presenceof oxygen and alkalis in the mineral. Orygen. Using routine analytical procedures, summationsnotably below 100wt.% were obtained for both orickite and coyoteite. Because of our earlier experiencewith erdite, NaFeSz'2HzO(Cza- manskeet al.,1980), we suspectedthe presenceof water or hydroxyl ion. Subsequentanalysis with a TAP crystal, using Fe2O3 for comparison (360 counts/sec)and FeS for background (3 counts/sec), showed that orickite contains up to 5 wt.Vo oxygen. Due to the extremely limited amounts of sample Fig. l. Intergrown crystals of orickite in sodalite (dark gray). available for both minerals, we were unable to The lqng dimension of the photograph is 0.44 mm. conduct other tests for the presence of water or ERD AND CZAMANSKE: ORICKITE AND COYOTEITE 247

Table 2. Chemical compositionsof orickite and chalcopyrite

l,leight Z Aton g Mol Z FeS (CuFe52{eS) Cu Fe Cu Fe S Cu/Fe lle/S

CuFe52 34.63 30.43 34.94 25.0 ?5.0 50.0 1.00 1.00 0.0 Orick i te* 32.9 32.? 34.9 23.7 26.4 49.9 0.90 1.01 10.2 Fe-rich cp** 32.9 32.3 34.8 23.7 26.5 49.8 0.90 1.01 10.6 Fe-rich cp+ 3l .1 33.2 35.7 ?2.3 27.0 50.7 0.83 0.97 t7.4 Fe-rich cpff 3l .0 34.3 34.6 23.3 28.2 49.5 0.79 I .02 L7.4

t Analysis from Table 1, omitting alkalis and oxygen, and recalculated to 100 rrtz.

** Synthetic. Data of Sugaki et al. (1975): Run ilo. 074 (at 300"C). (See also (1e81). Hutchinson and Scott

Natural. oata of Picot and Fevrier (1980) for chalcopyrite fron the East Pacific Rise (Gulf of California).

ft Natural. D1!1 of Karpenkovet al.(1974) for chalcopyrite from the Talnakh and 0ktyabrsk cu-Ni sulfide deposits, USSR. Averageof T-we-ntyanalyses (modified here to exclude Ni, 0.27 wtf and Co, 0.OZ).

hydroxyl ion. The amount of oxygen in orickite been reported in the resulting products. On the appearsto vary from grain to grain becausesumma- other hand,on the basisofluminescence and reflec- tions of analyzedelements range from 94.9 to 98.5 tancespectra, Shalimova et al. (1974a,b)found that wt.Vo.This range in summationswas obtained from K* ions were incorporated into sphalerite grown freshly polished surfaces, and because these sur- from hydrothermal solutions of KOH. The K+ ions faces show only slight tarnish after more than two introduced into the ZnS produced stacking faults years exposure, significantoxidation or hydration and point defects. Colaitis et al. (1976)have pro- of orickite during the course of our study seems posed that a defect structure of wurtzite might be unlikely. Skinner and Barton (1960) showed that produced by the incorporation of Ce3+ ions into small amountsof oxygen (up to 0.2 wt.Vooxygen) that structure. While Na and K may play a role in can substitute for sulfur in wurtzite formed at low the wurtzite-like structure of orickite, they are of temperatures.No report of oxygen in either natural little compositional importance, and we ignore them or synthetic chalcopyrite is known to us. The in discussing the relation of orickite to the other maximum amount of oxygen measuredin orickite is chalcopyritelike minerals. less than half that needed to form a single mole of Although various Na-Cu and K-Cu sulfides are water or hydroxyl ion. The role and limits of oxygen known (Burschka, l979a,b; Brown et al., 1980), (and probably ) in orickite must await none have any apparent relations with orickite. discovery of more material or synthesis of the More closely related chemically to orickite, and mineral. Here we consider orickite on an oxygen- discussedlater in this paper, are some Na- and K- free basis. bearing copper-iron sulfidesfrom the Khibina mas- Alkalis. Na and K also were found to vary in sif, describedby Dobrovol'skayaet al. (1977,1979). amount from grain to grain, independent of the Chemical properties. Orickite is insoluble or variation in summation (apparent oxygen content). slightly soluble in cold 1:1 HNO3 or HCI but is If Na and K were combined as alkaline hydroxides readily soluble in hot acids of the same concentra- or oxides, their maximum concentration deter- tion. Lack of material precluded thermal studies of mined requires less than one-third of the minimum orickite. apparent oxygen content. Although alkaline solu- Synthesis. Orickite has not been found as a tions containingNa+ and K+ ions have been em- syntheticphase so far, despiteextensive studies of ployed in many synthesesof chalcopyrite (e.g., the Cu-Fe-S and related systems (Barton, 1973; Barnard and Christopher, 1966;Lee et al., 1975; Cabri, 1973;Leeet al., 1975;Moh, 1975;Sugaki et Moh, 1975;Sugaki et al., 1975),no Na or K has al., 1975;Dutrizac, 1976;Vorob'ev and Borisov- ERD AND CZAMANSKE: ORICKITE AND COYOTEITE skii, 1980).Its absenceprobably arisesfrom causes readings were taken without changing the settings similar to the difficulty in synthesizingeither cuban- of the light source. From graphical plots, maximum ite or haycockite: according to Cabri (1973), slow reflectancevalues for orickite are 34.7, 39.9,42.8, cooling over geologic time may be required to form and46.9(at470,546,589, and 650 nm, respectively, theseorthorhombic structuresfrom a high-tempera- with elongation EW). On the best plots, reflectance turefcc phase.The difficulties of both synthesisand shows a straight-line variation that contrasts with recognition of the phases formed, and the impor- the reflectance curves of chalcopyrite (Aray a et al., tance of the cooling rate in the formation of the 1977).The quality of the grains and the high magni- various polymorphs of metal-enrichedchalcopyrite, fications neededare such that minimum-reflectance were demonstratedby McConnell (1978)and Putnis valuesare not given.With grainsin the NS position, (1978).We have not attemptedto synthesizeorick- reflectance values are so similar to those for EW ite. that a meaningful difference could not be estab- lished. Physical properties X-ray crystallography Orickite is brass yellow with a black and metallic luster. There is a good on {001} The poor quality of the orickite crystals limited and the mineral has conchoidal fracture. The hard- the information that we have been able to gather. nesscould not be measured,although the mineral is The X-ray powder diffraction patterns show diffuse easily scratched with a steel needle. The specific and relatively broad lines, and the reflections in the gravity could not be measured, due to contamina- single-crystal X-ray precession photographs are tion by epoxy resin, but the calculated is streakedand appear as short arcs except inthe hkn 4.212 g cm-3 with Z : 4. Orickite is weakly net. Only Laue arcs and no zero-order ring appear magnetic. in cone-axis[c] photographs.Nevertheless, prelimi- nary data were sufficient to characterizeorickite as Optical properties having a wurtzite{21{) unit cell with a : 3.695,c : -r0.01A), In polished section orickite is bright, pale yellow, o. to,{-(both and V : 72.8A3. The largest similar in color to, or slightly lighter than, chalcopy- coherent crystal analyzed (0.05 x 0.38 mm) was rite. The lamellar cleavageof orickite is distinctive extractedfrom specimenTT-CYP-134and was used (Fig. 1). Reflectionpleochroism is weak, from pale to obtain hk{, h\l, Dkl, and cone-axis [c] photo- to slightly deeperyellow, with maximum absorption graphs with Zr-filtered Mo radiation. This crystal with the cleavagetrace parallel to the plane of the detachedfrom the goniometer head during prepara- polarizer (NS for our microscope). Anisotropism is tion of the 0k/ net and was lost; it becamenecessary strong (in contrast to chalcopyrite); colors change to duplicate and continue data collection with a from grayish brown to grayish blue. There are no singlecrystal ofpoorer quality from anotherspeci- internal reflections. and no external form is ob- men (78-CYP-250). A fragment from the second servedin polished sections. Good polished surfaces crystal was used for the X-ray powder photograph' are obtained on orickite; this fact and other obser- Table 3 lists the X-ray powder diffraction data; vations suggestthat its hardnessis more like that of the pattern is simple and may be indexed complete- chalcopyrite (4) than of erdite (ltlz). Polished sur- ly by using the wurtzite-(21{) cell. The data are faces or orickite remained bright for at least a year compared with those of the synthetic compound in Menlo Park. California. Cu2FeSiS4, described by Schiifer and Nitsche Reflectivity values in air (measured by John (1974)as being an orthorhombic superstructure of Jambor, Canada Centre for Mineral and Energy wurtzite. The reflections indicating orthorhombic Technology), were obtained by comparison with symmetry in Cu2FeSiSaare all very weak (intensi- N.P.L. silicon standard N2538.42.Because only ties less than 3). Although these reflections could small grains were available for measurement,a 60x not be found in the orickite pattern (with exposures objective had to be used end the areas measured as long as 65 hours), such weak lines in our pattern were reclangular. Each grain was alignedparallel to would be sufficiently diffuse to go undetected. a crosshair, and a total of 14 or 15 wavelength The I(100):I(002)ratio is reversedfrom that found readingswere taken throughout the spectrum (450- for wurtzite by Short and Steward (1955), who 662 nm). The samplewas then replaced immediate- demonstrated that grinding affects the relative in- ly by the Si standard, and the same wavelength tensities of these peaks. The orickite used for the ERD AND CZAMANSKE: ORICKITE AND COYOTEITE 249

Table 3. X-ray powder diffraction data for orickite and related compounds

Calcu I ated* 0bserved Calcul atedt+ (l'lTZ2H) (lrTZ-sT) liurtzite (2!)** 0ri cki te*** Cu2FeSi54 f

hkr, dhk dhk t /A) ilA) J.t fuilEt $ks(A) dhk/A) hk!, 4.708 ; 4.732 011 ::: :_ ::: 4.428 3 4.438 r01 100 3.200 3.309 100 90 3.20 3.207 100 3.200 200,L20 002 3.080 3.128 86 100 3.@ 3.074 28 3.080 002 101 2.840 2.925 84 60 2.84 2.844 85 2.840 20r,L2L 2.598 I 2.598 LLz ::: ::: 2.363 1 2.366 o22 Loz 2.219 2.273 29 15 2.20 2.2L9 13 2.2L9 202,L22 110 1.848 1.911 74 70 1.85 1.852 48 1.848 040,320 r03 1.728 I.764 52 55 1.73 1.725 26 L.728 2O3,L23

200 r.600 1.654 10 r.603 6 1.600 400,240 112 1.584 1.630 45 30 I .583 1.585 16 1 .584 042,322 201 1.549 1.599 L2 3 I .543 1.551 3 1.549 40L,24L 004 1.540 1.564 2 1.540 004 202 1.420 I.462 5

104 1.388 I .414 L 203 1,.262 1.296 14 L.261 210 1.209 I .25r 6 -1: zLL 1.187 1.226 3 114 1.183 L.zLO 10 105 I .149 1.1 703 4 5 'ru 2L2 1.126 1.1611 8 204 1.110 I .1364 <1 300 1.067 I .1029 13 2L3 L.W2 L.0724 6 5 1.0r3 006 I.027 --: 302 1.008 1.0401 5 205 0.9761. 0.9979 6

Indexingbased_on the wurtzite-(2!) structure. The$lxvalues (>0.975)are calculatedfor orickite with a=3.6954,c=6.16. ** Synthetic c-ZnS; data from Swansonand Fuyat (1953). Diffractometer; CuKcradiation.

rH* Specimen78-CYP-250. Film 947: Debye-Scherrercamera (114.6 nmtlia.); FeKcradiation; Si used as internal standard; 65 hours exposure. Intensities estimated viiually. data :{t*li9-C!?f"!ilti from Schir?erand Nitsche (1974). Guinier camera;CuKo radiation; a=6.411A,b=7.404, c=b.140 (g and b interchangedfrcxn Schafer and Nitsche).

tt Indexing basedon the liurtz-stannite structure (Schf,ferand Nitsche, 1974). The (>1.540A)are calculated $lxvalues for orickite with a-6.40A,b=7.39, 9=6.16.

powder photograph was not ground but was the central part of the Cu-Fe-S system,just outside crushed between two glass slides and further the field of the intermediate solid solution shown by crushed during mixing with the mounting medium, Cabi (1973,p. 44'7,Fig. 5). In their study of the using a steel needle. A spherical mount reduced the structure of haycockite, Rowland and Hall (1975) efiects of preferred orientation. pointed out that all minerals with compositions in the central part of the Cu-Fe-S system have, at Discussion some temperature, a sphaleriteJike arrangementof Relation to chalcopyrite-like minerals. Disregard- close-packed layers of sulfur atoms tetrahedrally ing the minor alkalis and oxygen, orickite lies near coordinated to the copper and iron atoms. Hall chalcopyrite on the chalcopyrite-cubanite join in (1975)stated further that the metal-rich minerals in 250 ERD AND CZAMANSKE: ORICKITE AND COYOTEITE this part of the Cu-Fe-S system are related to Table 5. Comparisonof axial ratios of chalcopyrite-like and ZnS chalcopyrite by the presence of additional metal minerals in wurtzite-2'ilI setting atoms at interstitial sites of the cubic close-packed s(A) e(A) 4(A) g(A) cq !/ sulfur lattice. He noted that relative unit-cell vol- 3.774 5.146 90.80' l.628 (V/Z) I'|ooihoekite 10.585* umes increase with increasing metaUsulfur Sphalerite 5.409r* 3.824 6.246 90.00- 1.633 ratio and that the formulas for these minerals are all Putoranite 5.30*** 3.748 6.120 90.00- 1.633 stoichiometric. The close relation of orickite to Talnakhite 10.593* 3.745 6.116 90,00- 1.633 J./Or O.raf 89.16- L.637 these chalcopyriteJike minerals may be seen in Haycockite 10.705* 31.630 Chatcopyrite 5.292+ 10.40i 3.711 6.077 89,2I' 1.638 Table 4, in which all formulas are basedon 16 sulfur Fe-rich cp 5.30it I0.42 3.716 6.085 89.20" 1.639 atoms for comparison. The composition of orickite llurtzite 3.820tft 6.260 3.820 6.260 90.00' 1.639 (with Na, K, and O neglected) lies about halfway Cu2FeSi54 6.411'1, 6.140 3.702 6.140 90.00' 1.658 orickite 6.40W 6.16 3.695 6.16 90.00- L.667 betweenCuFeS2 and iron-rich chalcopyrite, (Dutri- zac (1976) suggestedthat about I 8 mole percent FeS Natural mineral (Hall, 19i5). &-3xtz, !=!ytz in wurtzite-2H (in the pseudobinarysystem CuFeS2-FeS)is the seEEtno. limiting composition for iron-rich chalcopyrite. The Syntneiic e-zns (Skinnerand Barton,1950). compositional limits of chalcopyrite were also dis- Natural mineral (Filiminovaet al., 1980). cussedby Barton and Skinner (1979)). T Synthetic stoichiometricchalcopyrite (cp) (Adams,1974). A further similarity between orickite and the +t Iron-rich chalcopyrite frm the Talnakh and 0ktyabrsk Cu-l{i deposits, (Karpenkovet al., 1974). chalcopyrite-like minerals is that the strongest liqe sulfide USSR (Swanson 1953). in all their X-ray diffractionpatterns, at 3.04-3.084, fit Synthetic czns and Fuyat, u Synthetic (Sch'a'ferand Nitsche' 1974). correspondsto the {111}plane of hexagonalclose- packed sulfur in sphalerite. In chalcopyrite this is W This study. the {112}plane which is the most important poly- synthetic twinning plane in its deformational twin- ning (Kelly and Clark, 1975)and correspondsto the (1.66) suggeststhat the true structure of orickite {001}plane of wurtzite and orickite. All the chalco- may not be identical to that of wurtzite. pyrite-like minerals have been placed (Table 5) in a Relation to wurtz-stannite comporznds.This high wurtzite-(2ll) pseudocell, using the vectors corre- axial ratio is our best present evidencethat orickite spondingto [111]sPr'and [011]"Pfras [001]-" and may be related to a large group of ternary and [100]-", respectively. When the chalcopyrite-like quaternarychalcogenides which possessa distorted minerals, together with sphalerite and wurtzite, are wurtzite structure. This structure is an orthorhom- arrangedin order of increasingC/A (Table 5), it may bic supercellof wurtzite that arisesfrom an ordered be seen that orickite and the synthetic compound arrangementof cations on former Zn sites and has Cu2FeSiS4are set apart by their high C/A ratios. oorth - 2owtz, Sorth - 3a-rr, and corrh - c.rr. Even allowing for the uncertainty of the axial Compoundswith this structure are strongly pseudo- parametersof orickite, the lowest possible C/A hexagonal and have axial ratios in the wurtzite

Table 4. Comparisonof orickite with other chalcopyriteJike minerals

Mineral Forrnula(5=16) Me/s v/z(A31 g Reference Chalcopyri te CusFeB516 1.000 72.9 4.18 Adams(1974 Synthetic 1.000 72.9 3.14 Schafer and Nitsche (1974) CurFeOSiOSrU 0ri cki te* cu7.6F"B.ssr6 I .005 72.8 4.19 This study et al. (1974) Fe-rich cp cuz.2F"9.rsr6 1.020 73.2 4.20 Karpenkov Talnakhi te Cu9Fe8Sl6 I .063 74.3 4.28 Hall (r97s) Putorani te 74.4 4.43 Filimonovaet al. (1980) CugFegS16 1.125 Mooihoekite Cu9Fe9Sl6 L.L25 75.4 4.37 Hall (197s) Haycockite CugFel0Sl6 1.125 75.7 4.33 Hall (1975)

* Na, K, and 0 omitted. ERD AND CZAMANSKE: ORICKITE AND COYOTEITE 251

subcell that are all close to or exceed 1.65. The Table 6. Electron-microprobeanalyses of coyoteite name "wurtz-stannite" was applied to the distorted I'lt 2* Range Cal.c. compn. wurtzite structure by Schiifer and Nitsche 0974\. NaFe355'2H20 Orickite may be the first mineral representative of the wurtz-stannite structure type. Na 5.99 ( 5.94- 6.01) 5.94 A wurtzite analog to chalcopyrite was first found Fe 44.0 (43.7 - 44.3) 43.31 in ftNaFeO2 by Bertaut and Blum (1954) and s 41.3 (40.e - 4L.7) 41.44 Bertaut, Delapalme, and Bassi (1964). Because of Hzo 8.71** 9.31 the presenceof and oxygen in orickite, we considered the possibility of an interlayered struc- Total 100.00 100.00 ture consisting of slabs of B-NaFeO2and CuFeS2, analogous to the slabs found in (Evans. Averageof five grains analyzeoat 10kV, using 1968).However, the contents of Na. K. and O in synthetic FeSand a natural crocioolite (4.63 wt %Na)as standaros. Six to ten spots per orickite are far too low to permit such a possibility. grarn v{ereoccuple0. Na-K-Cu-Fe suffidesfrom the Khibina massif. Rasvumite grains from the (Cza- By oifference. K<0.2 nt7; sought for by Khibina massif wavelengthdispersive spectrometry, but not manske et al., 1979) contain small amounts of a detecteo: Cl, Cu, Mg, ano Ni. phase simiiar in appearanceto orickite. The grains are too small to obtain an X-ray diffraction pattern, but electron-microprobe analyses of two grains As in the case of orickite, all analyses sum to (weight show percent):Cu23.2,21.6;Fe 37 .4,38.8; about nine weight percent too low. Qualitative S 28.4,30.2;O 11.8,9.4(by difference).The aver- analyseswith a TAP crystal confirmed that oxygen age composition of these grains is quite distinct is present in coyoteite. No other element with an from that of orickite but is close to that of a atomic number greater than 11 was detected in the hypotheticalhydroxycubanite, CuFeS3(OfD2 (ide- energy-dispersivespectra, and so we assume that allyCu 20.80,Fe36.57, S 31.49,and O 11.14).This oxygen and hydrogen account entirely for the nine- phasewas found independentlyby Dobrovol'skaya percent deficiency in the analyses. There must, et al. (1979)in the Khibina massif, where it occurs therefore, be two atoms of oxygen per formula, with both rasvumite and djerfisherite. Dobrovol' although the further question of whether these exist skaya et al. (1977, 1979)also found and partiallv as water or hydroxyl ion remains unresolved. By describedseveral other Na- and K-bearingiamellar analogywith erdite, we offer the provisional formu- copper-iron sulfides in complexly intergrown mate- la NaFe3S5.2H2Ofor coyoteite. We could find no rial in the Khibina massif. One of these sulfideshas published record of a hydrous or anhydrous sodi- a chalcopyrite-like structure and a composition near um-iron sulfide near this composition. Cu2FeS3,but neither this phase noi any of the Coyoteiteis insoluble,or very slowly soluble,in others has a composition or X-ray data near to that cold 1:1 HCI or HNO3, but it dissolvesreadily in of orickite. hot acidsofthese concentrations.It altersto unde- termined decomposition products in a matter of Coyoteite months. Neither thermal studies nor a qualitative determination of water could be made with the Chemistry limited material at hand. The electron-microprobe data in Table 6 were obtained on five discrete grains from specimen Physical properties number 77-CYP-134for which was found a nearly Coyoteite is black in incident light and has a black constant high sodium content. The largest of these streak; its luster is metallic, and the mineral is grainswas only 0.2 x 0.4 mm in size. Many other opaque in the smallestfragments. No crystal forms grains, similar to appearance to coyoteite, were were observed in the polished sections. Coyoteite found to containlesser amounts of sodium,presum- has perfect flll} cleavage,which most grains dis- ably as a result of alteration and leaching. One play conspicuouslyin polished sections. An unusu- relatively large analyzed grain was removed from al chevron pattern is commonly developed by op- the polished section for X-ray difraction and other posing sets of cleavage lamellae (Fig. 2). The studies. measured specific gravity ranges from 2.5-2.6 but 252 ERD AND CZAMANSKE: ORICKITE AND COYOTEITE

Discussion The data that we could obtain from coyoteite were limited both by the scarcity and ephemeral nature of the mineral; it alters to undetermined decomposition products. Until more and better crystallized material is either found or synthesized, it is impossible to know whether the mineral con-

Table 7. X-ray powder diffraction data for coyoteite

!!c e (l) sll)- I - hL4 llr

010 9.62 9.6 60 100 7.I27 7.L3 90 Fig. 2. Coyoteite crystals showing chevron pattern developed 001 ri.163 6.15 20 by opposing cleavage sets. Continuous parallel lines are 110 6.055 5.60 60 polishing scratches. The long dimension of the photograph is 0T1 5.590 0.26mm. T10 5.461 Iol 5.311 s.31 40 TI1 5.L29 5.L2 100 011 4.875 020 4.831 4.827 15 these values are low becauseof minor contamina- tion by epoxy resin along the cleavage lamellae. T11 4.290 L20 4.2L5 4.199 20 The calculateddensity is 2.879gcm-3 for Z : 2. 101 4.204 Coyoteite is moderately magnetic. oVt 4.113 VL 4.016 :_= Opticalproperties 1T1 3.911 3.910 50 L20 3.813 Under the ore microscope, coyoteite is pale 111 3.801 brownish gray with a pink tint. Reflection pleochro- 200 3.564 02L 3.552 3.552 50 ism is faint, from grayer to pinker. Anisotropism is strong; colors between crossed polars changefrom 8t 1.199 3.4s6 20 ML J..t5l. gray to dull golden orange. Internal reflection is 030 3.22L 3.222 15 absent.Although reflectanceand hardnesshave not 003 3.081 3.080 70b 220 3.028 3.029 80b been measured.the hardnessis estimatedto be near that of erdite (approximately 1/z (Mohs)). Coyoteite frz 2.8? 2.884 10 is so soft that the most carefully polished surfaces oL? 2.816 2.808 20 of the mineral show scratches(Fig. 2). 20L 2.81s T? ?.709 2.707 20b IJI 2.529 2.528 10 X-ray crystallography 230 2.528 X-ray precessionphotographs (Mo radiation, Zr 2.404 30 2.365 30 filter) of an analyzed single crystal show coyoteite 2.LU 10 to be triclinic, spacegroup Pl or Pl. The crystal, 1.901 80 L.877 20 however, proved to be of poor quality, and reflec- L.862 20 tions are streaked and diffuse. A small piece of the (but ground), crystal was detached,crushed not and All calculatedhkt's listgd for.d61g> usedto obtain the powder diffraction data (Table 7). j.sOOA. All d61o> 2.5004are inilEfe?f. Indices from liiit:squares analysis of X-ray The unit-cell dimensions refined by least-squares powderdata using the ciigital computerprogram of analysis of the X-ray powder diffraction data are Applemanand Evans(1973). : (estimatedstandard deviations in parentheses):4 ** specimenlio. 77-cYP-134. Film ]rh. 904: Fe/l4n 7.409(8),b : 9.881(6),c : 6.441(3)4, raciiation; lFeKc= 1.937284. Debye-Scherrer : .t : cameradiameter 114.6 mn; film correcteo for 101'25(3)"p 104"37(5)" 81"29(5)"and v: shrinkage. 446.2(5)A'. ERD AND CZAMANSKE: ORICKITE AND COYOTEITE 253 tains hydroxyl and (or) hydrate water. From the Chukhrov, F. V. (Ed.) (1978)Mineralogy of the Khibina massif. properties that we have been able to determine. we (in Russian)V. l, V. 2. Moscow, Izdatelstvo Nauka. (1976) can find no other mineral or synthetic compound Colaitis, D., Caro, P. E., and Loriers, J. D€fauts dans le wurtzite lies a la pr6sence petites that is de inclusions de cdrium. closely related to coyoteite. Its perfect Materials ResearchBulletin. ll. 437-444. cleavage, however, suggeststhat coyoteite has a Czamanske,G. K., Leonard, B. F., and Clark, J. R. (19E0) layered structure that together with the chemical Erdite, a new hydrated sodium iron sulfide mineral. American composition, would place coyoteite near to (but Mineralogist, 65, 509-515. distinct from) the valleriite series of minerals. Czamanske,G. K., Erd, R. C., Leonard,B. F., and Clark, J. R. (1981)Bartonite, a new potassiumiron sulfidemineral. Ameri- Acknowledgments can Mineralogist, 66, 369-375. Czamanske,G. K., Erd, R. C., Sokolova,M. N., Dobrovol'ska- Special appreciation is due J. H. G. La-flamme and John ya, M. G., and Dmitrieva, M. T. (1979)New data on rasvu- Jambor of the CanadaCentre for Mineral and Energy Technolo- mite and djerfisherite. American Mineralogist, 64, 776-:77 E. gy, who, through microprobe and X-ray studies, confirmed our Dobrovol'skaya,M. G., Sokolova, M. N., and Tsepin, A. I. early designationof orickite as a new mineral and obtained the (1979)Chemical composition of potassium-containingsulfides reflectivity data. We also appreciate the counsel and advice from the Khibiny Massif. (in Russian)Akademiya Nauk SSSR received ofour colleaguesJoan R. Clark and Howard T. Evans, Izvestiya, Seriya Geologicheskaya,1979 (6), 152-156. Jr. For thoughtful, critical reviews, we thank paul B. Barton. Jr.. Dobrovol'skaya,M. G., Sokolova,M. N., Tsepin, A. I., and Howard T. Evans, Jr., and Steven D. Scott. Especially helpful Organova, N. I. (1977) Nonuniformity of segregationsof a were severaltranslations from the Russianliterature bv Michael potassium-containingsulfide with chalcopyrite-like structure. Fleischer. (in Russian)Neodnorodnost' Mineralov i tonkie Mineral'nye References Smesi.1977.65-68. Dutrizac, J.E. OnO Reactions in cubanite and chalcopyrite. Adams, R. L. (1973) The preparation and characterization of CanadianMineralogist, 14, 172-181. chalcopyrite and related phases. Ph.D. Dissertation, Brown Evans, H. T., Jr. and Allmann, Rudolf (1968) The crystal University. (not seen; extracted from Dissertation Abstracts, structure and crystal chemistry of valleriite. Zeitschrift fiir 834,4318, 1974). Kristallographie, 127, 73-93. Araya, R. A., Bowles, J. F. W., and Simpson, p. R. (1977) Evans, H. T., Jr. and Clark, J. R. (1981)The crystal structure of Reflectanceand composition of chalcopyrite from El Teniente bartonite, a potassiumiron sulfide, and its relationship to the ore deposit, Central Chile. Neues Jahrbuch fiir Mineralogie structures of pentlandite and djerfisherite. American Mineral- Monatshefte, 461467. ogist, 66, 376-384. Barnard, W. M. and Christopher, P. A. (1966)Further study of Filimonova, A. A., Evstigneeva,T. L., and Laputina, I. P. the efectiveness of aqueous solutions in the hydrothermal (1980)Putoranite and nickeliferous putoranite-new minerals synthesisof chalcopyrite. Economic Geology, 61, 1287-nqJ. of the chalcopyrite group. (in Russian)Vsesoyuznogo Miner- Barton, P. B., Jr. (1973)Solid solutions in the system Cu-Fe-S. alogicheskogoObshchestva, Zapiski, 109, 336-341. Part I: The Cu-S and CuFe-S joins. Economic Geology, 68, Hall, S. R. (1975)Crystal structures of the chalcopyrite series. 455465. CanadianMineralogist, 13, 168-172. Barton, P. 8., Jr. and Skinner, B. J. (1979)Sulfide mineral Hutchinson,M. N. and Scott, S. D. (1981)Sphalerite geobaro- stabilities.In H. L. Barnes, Ed., Geochemistryof Hydrother- metry in the Cu-Fe-Zn-S system. Economic Geology, 76, mal Ore Deposits, p. 27840!. John Wiley and Sons, New 143-153. York. Karpenkov,A. M., Mitenkov, G. A., Rudashevskii,N. S., So- Bertaut, E. F. and Blum, Pierre (1954)Structure d'une nouvelle kolova, N. G., and Shiskin, N. N. 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S., Takenouchi, Sukune, and Imai, Hideki (1975)Syn- state structure and electronic properties of a mixed-valence theses of stannoidite and mawsonite and their genesisin ore two-dimensional metal, KCuaS3. Inorganic Chemistry, 19, deposits. Economic Geology, 70, 834-843. l%5-1950. McConnell, J. D. C. (197E)K-space symmetry rules and their Burschka, Christian (1979a)Na3CuaSa-ein Thiocuprat mit un- application to ordering behaviour in non-stoichiometric(met- verkniipften o[CuaSo]-Ketten.Zeitschrift f0r Naturforschung, al-enriched)chalcopyrite. Physicsand Chemistry of Minerals, 34b,396-397. 2,253-265. Burschka,Christian (1979b)Zur Kristallstruktur der Thiocuprate Moh, G. H. (1975) Tin-containing mineral systems. Parr II: K3CusS6und Rb3CusS6.Zeitschrift ftir Naturforschung, 34b, Phaserelations and mineral assemblagesin the Cu-Fe-Zn-Sn- 675-677. S system.Chemie der Erde, 34, l4l. Cabri, L. J. (1973)New data on phaserelations in the Cu-Fe-S Parth6, E., Yvon, K., and Deitch, R. H. (1969) The . Economic Geology, 68, 443454. structure of Cu2CdGeSaand other quaternary normal tetrahe- 254 ERD AND CZAMANSKE: ORICKITE AND COYOTEITE

dral structure compounds.Acta Crystallographica,825, 1164- Short. M. A. and Steward, E. G. (1955)X-ray powder diffraction 1174. data for hexagonalzinc sulphide. Acta Crystallographica' 8' Picot, P., and Fevrier, M. (1980)Etude mineralogiqued'6chantil- 73t-:734. lons du Golfe de Californie (CampagneCyamex). Document Skinner, B. J. and Barton, P. B., Jr. (l%0) The substitution of du Bureau de Recherches G6ologiques et Minidres. Paris, oxygen for sulfur in wurtzite and sphalerite.American Miner- France. Number 20, l-52. alogist,45, 612-425. Putnis, A. (1978)Talnakhite and mooihoekite: the accessibility Sugaki,A., Shima, H., Kitakaze, A., and Harada, H' (1975) of ordered structuresin the metal-rich region around chalcopy- Isothermal phase relations in the system Cu-Fe-S under rite. CanadianMineralogist, 16, 23-30. hydrothermal conditions at 350"Cand 300'C. Economic Geol- Rowland,J. F. and Hall, S. R. (1975)Haycockite, CuaFe5S6: a ogy, 70, 806-823. superstructurein the chalcopyrite series.Acta Crystallograph- Swanson,H. E. and Fuyat, R. K. (1953)Standard X-ray diffrac- ica, B31, 2105:2112. tion powder fatterns. National Bureau of StandardsCircular Schiifer, W. and Nitsche, R. (1974) Tetrahedral quaternary 539.II. 14-15. chalcogenidesof the type Cu2-II-IV-Sa(Sea). Materials Re- Vorob'ev. Yu. K., and Borisovskii, S. E. (1980)The phase searchBulletin. 9. 645-654. transformation and composition of chalcopyrite. (in Russian) Shalimova,K. V., Morozova, N. K., Malov,,M. M., Kuznet- Akademiya Nauk SSSR Izvestiya, Seriya Geologicheskaya, zov,Y. A., Shternberg,A. A., and Lobachev,A. N. (1974a) 1980(8), 86-101. Effect of the conditions of synthesison the optical properties Yakowitz, H., Myklebust,R. L., and Heinrich, K. F. J. (1973) of zinc sulfide crystals grown by the hydrothermal method' FRAME: An on-line correction procedure for quantitative Soviet Physics Crystallography, 19, 86-89. electron probe analyses.National Bureau of StandardsTech- Shalimova.K. V.. Morozova, N. K., Kuznetzov, V. A., Ko- nical Note 796, 146. tel'nikov, A. P., and Veselkova,M. M. (1947b)Defectiveness of sphalerite crystals grown in alkaline hydrothermal media. Manuscript received,January 22, 1982; Soviet Physics Crystallography, 19, 392-394. acceptedfor publication, July 26, 1982.