American Mineralogist, Volume 76, pages299-305, 1991 NEW MINERAL NAMES* JonN L. Javrnon CANMET, 555 Booth Street,Ottawa, Ontario KIA OGl, Canada Eowl,no S. Gnnw Department of Geological Sciences,University of Maine, Orono, Maine 04469, U.S.A. platy either with a rhombic outline, or equant with a L.v.Razin, o.o. AnyuiiteAupb,-A nearly squareoutline. The mineral forms complex inter- ,,u".lJ,lt,liD possibly new intermetallic of gold and lead. Mineral . Zhumal, growths of three types with native lead, resulting I l(4), 88-96 (in Russian). from breakdown of solid solutions. In the intergrowths, anyuiite typically forms platy aggregatesranging from 1- Electron-microprobe analysesof the mineral and of an 50 pm acrossand 100-900 pm long, and prismatic crys- gave antimony-bearing variety Au 32.6, 34.3, 36.7, Ag tals 50 x 100 pm. Associatedminerals include ilmenite, 0.35,not detected,Pb 64.8, 59.0,52.9,Sb 0.3, 5.8, 10.2, titanian magnetite,chrome spinel, hematite, pyrite, chal- sum 98.05, 99.1, 99.8 wto/0,corresponding to (Au,or,- copyrite, and apatite. Sourcesof the mineral are small A& orr)",or, (Pb, n*rSbo o,r)", ooo, Au, oon(Pb, ,,rSbo ,rr)", ooo, Hercynian ultrabasic-gabbroid massivesderived from a and Au, r0r(Pbr s07sb0onr)", *0. Fragmentsare opaque, sil- platinum-bearing dunite-harzburgite magmatic forma- gray, very luster metallic. Oxidizes after 1.5-2 days, be- tion in the Anyui eugeosynclineof the Koryak-Kam- gray (sil- coming dull lead-gray. In reflected light, light chatka fold province. The mineral is named for the lo- very) with a faint creamy tint, fairly highly reflecting; cality (Bolshoi Anyui River basin). A polished section bireflectancebarely noticeable; commonly oxidized, be- containing anyuiite is in the Fersman Mineralogical Mu- gray poorly coming dark with a blue-black cast and re- seum of the USSR Academy of Sciences,Moscow. gray. flecting. Weakly anisotropic from silvery gray to Discussion. There are several discrepanciesbetween the The antimony-bearing variety is indistinguishable opti- reported intensities in the X-ray patterns for anyuiite and proper, cally but is slightly less reflecting than anyuiite synthetic AuPbr: notably, anyuiite is reported to have an (WTiC for which R, and R. at 20-nm intervals standard) intensity of 60 for ll} (5.22 A; vs. 6 for AuPbr, and l0 are: 420 56.7, 50.3; 440 59.0, 52.9; 460 60.7, 55.0; 480 vs. I 00 for 002; also, a line of intensity 45 and three lines 62.0,5 6.2; 50062.4, 57 .7 ; 52063.2, 58.3; 5 40 63.9,59.3; with intensities of l8 to 20 in synthetic AuPb, are missing 56064.6,59.9; 580 65.r,60.7;60065.6, 6r.4;620 66.0, in the pattern of the natural material. None of the lines 62.r; 640 66.r, 62.6;660 66.2,63.0; 680 66.5,63.4; 7 00 reported in the pattern of the natural material were as- : 66.8, 63.7. VHN2. 146 (range142-152.8), decreasing signed an intensity of 100. The phasehas been reported to 101 (range 100.8-104) for the antimony-bearingva- by other authors as inclusions in a kimberlite pipe, and riety. Plastic and malleable, nonmagnetic.The mineral is data were abstracted in Am. Mineral., 75. 931, 1990. too frne grained for single-crystal study. By analogy with E.S.G. synthetic AuPbr, tetragonal, spacegroup l4/mcm. From powder-diffraction data, a : 7.39(2), c : 5.61(3) A, D*. : 13.49g/cm3 with Z: 4.Lines attributed to the mineral Efremovite* are 5.22(60,1 l0), 3.74(20,200), 2. 8 2( I 0,002, possibly this Ye.P. Shcherbakova,L.F. Bazhenova (1989) Efremorrite 2ll), 2.59(20,220), reflection is a sum of 002 and (NHo)rMg,(SOo)r-Ammonium analogue of langbein- 2.48(10,I l2), 2.23(30,202),l.l 55(20,433),and l. I 30- ite-A new mineral. Zapiski Vses. Mineral. Obshch., (20,541). The remaining six lines in the pattern (intensity I l8(3), 84-87 (in Russian). rangesfrom 20 to 50) are attributed to gold. gave The mineral occurs in concentrates of gold-bearing A chemical analysis SO, 38.37, FeO 0.72, CaO alluvium from tributaries of the Bolshoi Anyui, north- 0.35, MgO 11.47,MnO 0.25, NarO 0.13, K2O 0.50, (NHo)rO 100.07 eastern USSR. Associated minerals in the concentrates 8.31,insoluble residue 39.97, sum wt0/0, (Mg' include gold, platinum, iridosmine, osmium, osmonrthe- corresponding to [(NHo), ool(oorNtu or]",o, ,nFoo.ou- Ceo S, O, ideally (NHo)rMgr(SOo)r.Sulfate niride [rutheniridosmine?], iridian-osmian laurite, chrome ooMnoor)", n, o, r, gravimetrically spinel, ilmenite, hematite, and sulfides. Polymineralic was determined with BaClr, magnesium gravimetrically pyrophosphate, + potas- grains containing the mineral, gold, and lead are with ammonia potassium photom- l-4 mm across,weakly rounded, angular, elongate and sium as chlorplatinate, and by flame etry. The insoluble residue is inferred to be organic ma- terial and quartz thal were admixed with the mineral. * Before publication, minerals marked with an asterisk were approved by the Commission on New Minerals and Mineral The mineral is soluble in water; upon heating with alkali Names, Intemational Mineralogical Association. and upon heating in a closed tube, ammonia is evolved, 0003-004x/9 1/0I 024299$02.00 JAMBOR AND GREW: NEW MINERAL NAMES and (NH4)rSO4melts out and subsequentlydecomposes Electron-microprobe analysis gave NarO 3.52, KrO with evolution of ammonia. In air at ordinary tempera- 2.68,MgO 0.06,MnO 31.14,FeO l.l2,BaO 8.88,Al,O3 tures, the mineral is hydrated to boussingaultite in the 0.03, SiO, 27.32,TiO, 9.44, ZrO, 0.12, Nb,Os 13.35, course of several days. The mineral shows an endother- H,O (TGA) 3.49,F 0.84,O = F 0.35,sum 101.64wto/o; mic effect at 430-495 "C (maximum 475 "C) accompa- the ideal formula NarKBaMnrTi4Si8O3,(OH) r. 2HrO re- nied by a weight loss of 35.80/oassociated with decom- quiresNarO 3.62,KrO 2.75,8aO8.96, MnO 33.16,TiO, position into MgSOo and (NHo)rSOoand breakdown of 18.68,SiO, 28.09, HrO 4.74, sum 100 wt0/0.Occurs in the latter (the calculated weight loss from the ideal for- pegmatite at Mont Saint-Hilaire as orange-brown, pris- mula is 35. 5olo). Occurs as equant grains,0.0 I -0.0 I 5 mm, matic to tabular crystals to I mm, elongate [00], flat- in gray to white aggregatesthat have a dull luster, fI: tened on {010}; forms shown by the crystalsare {001}, -2, uneven fracture, vitreous luster, no cleavage.Aggre- {010}, {100}, and hjl (possibly101); swallow-tailtwins gatesare opaqueexcept in thin slivers. In immersion oil, on twin plane {001} are common. Crystals are transpar- colorless to locally tinted weak brown, isotropic, n : ent to translucent, vitreous luster, pale brown streak, 11 1.550(1).Hydration resultsin zoned grains with aniso- : 4, very brittle, uneven fracture, perfect {001} cleavage, tropic margins of boussingaultite.No single-crystalXRD D--" : 3.71(5),D*,. : 3.81 g/cm3.Optically biaxial neg- data. Given the close correspondenceofthe powder pat- ative,u : 1.785(2),B : l.8l(l), r : 1.82(l),2V^"". : tern with that of the synthetic compound (PDF 18- 66(lf ,2V. b: 64, X : b, Z Ir c: 9.6' in the acuteangle 110),cubic, space group P2r3, a: 9.99(l)A, D-" : 2.52 B; strong dispersion,r < y; pronouncedpleochroism, X, I g/cm3 with Z : 4. The strongestlines (31 given) of the : lrght yellow, Z: dark orange-brown.Monoclinic sym- powder pattern are: 5.76(35,lll), 4.07(70,211),3.15 metry, spacegroup C2/c, a : 10.819(3),b : 13.822(5), (100,310),3.00(35,311), 2.668(50,321), and 1.620 c : 21.149(41A, B : 99.61(3)"as refined from X-ray (25,6rr). powder data; the cell parametersand ideal formula give The mineral occurs in the burning dumps from two D*r" : 3.64 g/cm3with Z : 4. A pronounced subcellwith shafts in the Chelyabinsk coal basin in the southern Urals, spacegroup A2/m, A2, ot Amhas a' : a/2, b' : b/2, c' USSR. At one shaft the mineral was deposited from hot : c, Z: l. Strongestlines of the X-ray pattern, in order gasesissuing from a fumarole. The deposit consists of of decreasingintensity, arc 3.47, 10.4,2.61, 3.19, 2.08, four layersoverlying red burning rock (l) unconsolidated and 2.87. The new name is for ProfessorGuy Perrault of material on top, (2) asphaltJike crust with crystalsof sul- Ecole Polytechnique,Montreal, Quebec. fur and kladnoite, (3) crusts and stalactitesof mascagnite, Discussion.The data were published with the permis- (4) densecementlike gray massesdominantly of efremov- sion of G.Y. Chao, who is to present the complete de- ite, hydrated in the upper part to boussingaultite.At the scription at alater date. The mineral was referred to pre- other shaft, the mineral occurs in a white, fine-grained viously as UKl7, for which Chao et al. (Can. Mineral., crust on an incompletely combusted area of the dump 9, 109-123, 1967) gave the strongest X-ray lines as that is enriched by a carbonaceousmass. The new min- 3.47(I 00), 3.I 9(40), 2.87(50), 2.60(40),1.729(308), and eral is interpreted to have formed by the decomposition 1.599(30).J.L.J.