Benjaminite

General Information: Chemical Formula:(Ag,Cu)3(Bi,Pb)7S12 Composition:(Molecular Weight = 2,134.46 gm)Copper 2.23 % CuSilver 11.37 % AgBismuth 48.95 % BiLead 19.41 % PbSulfur 18.03 % S  Empirical Formula: Ag2.25Cu0.75Bi5Pb2S12 IMA Status:Approved IMA 1975 Locality:Outlaw Mine, 12 miles north of Manhattan, Nye Co. Nevada, USA.Physical Properties: Cleavage:[???] Good Color:grayish yellow or copper. Density:6.7 Diaphaniety:Opaque Hardness:3.5 - Copper Penny Luminescence:Non-fluorescent. Luster:MetallicMore details...

(Ag,C )3(Bi,Pb)7S12