Iron, sulfosalts

Primary minerals formed in the ore deposit prior to weathering and erosion, including a wide variety of metal sulfides and sulfosalts, metal oxides, metal- and alkaline-earth carbonates, sulfates, crystalline silica, clays, and other silicates. Many metal sulfides (especially iron sulfides such as pyrite), when exposed by erosion or mining to atmospheric oxygen and water, can form acid-rock drainage (ARD). 

Reactions (1) and (4) result in strongly acidified solutions which, in addition to dissolve large amounts of Fe(II) and SO, also leach important quantities of many other major and trace metals from the mineralizations and the host rocks, including Al, Mg, and Ca (with minor Na, K, and Ba) from the accompanying aluminosilicates, carbonates, and sulfates, in addition to Cu, Zn, Mn, As, Pb, or Cd from other sulfides (sphalerite, chalcopy-rite, galena, arsenopyrite) and sulfosalts (tetrahedrite-tennantite). Iron and aluminum are usually the most abundant metal cations of those present in AMD [5, 9, 12, 22]. 

Chalcocite [22205-45-4] [Named from the Greek, chalkos, copper] (ICSD 100333 and PDF 33-490) Cu,S Ms 159.158 79.85 wt.% Cu 20.15 wt.%S (Sulfides and sulfosalts) Orthorhombic as 1188.1 pm bs 273.23 pm cs 1349.1 pm (Zs 96) Cuprite type Biaxial R = 32.2% 2.5-3 (HV 68-98) 5800 Habit massive, granular, euhedral crystals. Color black or iron black. Luster metallic. Diaphaneity opaque. Streak grayish black. Qea ige 110 indistinct. Twinning II0, 032, 112. Fracture Conchoidal. Occurrence secondary mineral in/near the oxidized zone of copper sultide ore deposits. Others p-type semiconductor with = 0.06 eV-0.13eV. Electrical resistivity 80 to 100 jQ.cm.> melting point of 1100 C... 

Coloradoite [Named after its occurrence in Smuggler mine, Boulder, Colorado) (ICSD 31086 and PDF 32-665) HgTe Ms 328.19 61.12wt.% Hg 38.88 wt.% Te (Sulfides and sulfosalts) Cubic a - 646.0 pm B3, cF8 (Z=4) S.G. F43m P.G. 43m Blende type Isotropic R s 35.4 2.5 (HV 25-28) 8070 Habit massive, granular. Color iron black. Luster metallic. Diaphaneity opaque. Streak black. Fracture conchoidal. 

Petzite [Named after the chemist, W. Petz] (ICSD 27539 and PDF 44-1420) Ag,AuTe, M = 667.90294 32.30 wt.% Ag 38.21 wt.% Te 29.49 wt.% Au (Sulfides and sulfosalts) Cubic P.G. 23 Isotropic R = 45% 2.5 8700- 9140 Habit massive, granular. Color iron black or steel gray. Luster metallic. Diaphandty opaque. Streak grayish black. Fracture brittle, sectile. 

Stephanite (syn., Brittle Silver Ore) [Named after the Austrian engineer, A. Stephan] (ICSD 16987 and PDF 11-108) Ag.SbS. M = 789.355 68.33 wt.% Ag 15.42 wt.%Sb 16.25 wt.% S (Sulfides and sulfosalts) Orthorhombic P.G. mm2 Biaxial 6250 L Habit pseudo hexagonal, tabular, massive. Color iron black. Diaphaneity opaque. Luster metallic. Streak black. Fracture subconchoidal. Cleavage [010] imperfect, [021] poor. 1... 

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