Yarrowite

General Information: Chemical Formula:Cu9S8 Composition:(Molecular Weight = 828.44 gm)Copper 69.03 % CuSulfur 30.97 % S  Empirical Formula: Cu9S8 IMA Status:Approved IMA 1978 Locality:Yarrow Creek, AB, Canada. Name Origin:Named for the locality.Physical Properties: Cleavage:[0001] Distinct Color:black or blue. Density:4.89 Diaphaniety:Opaque Habits:Tarnishes - Freshly fractured surfaces form a surface oxidation film, Massive - Uniformly indistinguishable crystals forming large masses., Hardness:3.5 - Copper Penny Luster:MetallicMore details...