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Lisiguangite,CuPtBiS_3,is a new mineral species discovered in a PEG-bearing,Co-Cu sulfide vein in garnet pyroxenite of the Yanshan Mountains,Chengde Prefecture,Hebei Province, China.It is associated with chalcopyrite and bornite,galena,minor pyrite,carrolite,molybdenite and the platinum-group minerals daomanite(CuPtAsS_2),Co-bearing malanite(Cu(Pt,Co)_2S_4)sperrylite, moncheite,cooperite and malyshevite(CuPdBiS_3),rare damiaoite(Pt_2In_3)and yixunite(Pt_3In). Lisiguangite occurs as idiomorphic crystals,tabular or lamellae(010)and elongated[100]or as aggregates,up to 2 mm long and 0.5 mm wide.The mineral is opaque,has lead-gray color,black streak and metallic luster.The mineral is non-fluorescent.The observed morphology displays the following forms:pinacoids{100},{010},{001},and prism{110}.No twining is observed.The a:b:c ratio,calculated from unit-cell parameters,is 0.6010:1:0.3836.Cleavage:{010}perfect,{001}distinct, {100}may be visible.H Mohs:2 1/2;VHN_(25)=46.7-49.8(mean 48.3)kg/mm~2.Tenacity:brittle. Lisiguangite is bright white with a yellowish tint.In reflected light it shows neither internal reflections nor bireflectance or pleochroism.It has weak to moderate anisotropy(blue-greenish to brownish)and parallel-axial extinction.The reflectance values in air(and in oil)for R_3,R_4 and(~(im)R_3,~(im)R_4),at the standard Commission on Ore Mineralogy wavelengths are:37.5,35.7(23.4,22.3)at 470 nm;38.6,36.5 (23.6,22.6)at 546 nm;39.4,37.5(23.6,22.7)at 589 nm and 40.3,38.2(23.7,22.9)at 650 nm.The average of eight electron-microprobe analyses:Cu 12.98,Pt 30.04,Pd 2.69,Bi 37.65 and S 17.55, totaling 100.91%,corresponding to Cu_(1.10)(Pt_(0.83),Pd_(0.14))_(Σ0.97)Bi_(0.97)S_(2.96)based on six atoms apfu.The ideal formula is CuPtBiS_3.The mineral is orthorhombic.Space group:P2_12_12_1,a=7.7152(15),b=12.838(3) ,c=4.9248(10),V=487.80(17)~3,Z=4.The six strongest lines in the X-ray powder-diffraction pattern[d in(I)(h k l)are 6.40(30)(020),3.24(80)(031),3.03(100)(201),2.27(40)(051),2.14(50)(250), 1.865(60)(232).
Lisiguangite, CuPtBiS_3, is a new mineral species discovered in a PEG-bearing, Co-Cu sulfide vein in garnet pyroxenite of the Yanshan Mountains, Chengde Prefecture, Hebei Province, China. It is associated with chalcopyrite and bornite, galena, minor pyrite, carrolite, molybdenite and the platinum-group minerals daomanite (CuPtAsS_2), Co-bearing malanite (Cu (Pt, Co) _2S_4) sperrylite, moncheite, cooperite and malyshevite (CuPdBiS_3), rare damiaoite (Pt_2In_3) and yixunite (Pt_3In) occurs as idiomorphic crystals, tabular or lamellae (010) and elongated [100] or as aggregates, up to 2 mm long and 0.5 mm wide. The mineral is opaque, has lead-gray color, black streak and metallic luster.The mineral is non-fluorescent. The observed morphology displays the following forms: pinacoids {100}, {010}, {001}, and prism {110} .No twining is observed. a: b: c ratio, calculated from unit-cell parameters , is 0.6010: 1: 0.3836.Cleavage: {010} perfect, {001} distinct, {100} may be visible. H Mohs: 2 1/2; VHN_ (25) = 46.7-49.8 (mean 48.3) kg / mm ~ 2.Tenacity: brittle. Lisiguangite is bright white with a yellowish tint. In contrast light it shows neither internal reflections nor bireflectance or pleochroism. It has weak to moderate anisotropy (blue-greenish to brownish) and parallel-axial extinction. Reflectance values in air (and in oil) for R_3, R_4 and (~ (im) R_3, ~ (im) R_4) at the standard Commission on Ore Mineralogy at averages of 37.5, 35.7 (23.4, 22.3) at 470 nm; 36.5 (23.6,22.6) at 546 nm; 39.4,37.5 (23.6,22.7) at 589 nm and 40.3,38.2 (23.7,22.9) at 650 nm. The average of eight electron-microprobe analyzes: Cu 12.98, Pt 30.04, Pd 2.69, Bi 37.65 and S 17.55, totaling 100.91%, corresponding to Cu_ (1.10) (Pt_ (0.83), Pd_ (0.14)) _ (Σ0.97) Bi_ (0.97) S_ (2.96) The ideal formula is CuPtBiS_3.The mineral is orthorhombic.Space group: P2_12_12_1, a = 7.7152 (15) , b = 12.838 (3) , c = 4.9248 (10) , V = 487.80 = 4. The six strongest lines in the X-ray powder-diffraction pattern [d in (h)) are 6.40 (30) (020), 3.24 (80) (031), 3.03 (201), 2.27 (40) (051), 2.14 (50) (250), 1.865 (60) (232).