Ourayite

General Information: Chemical Formula:Pb4Ag3Bi5S13 Composition:(Molecular Weight = 20815.77 gm)Silver 12.96 % AgBismuth 41.16 % BiLead 29.86 % PbSulfur 16.02 % S  Empirical Formula: Ag25Pb30Bi41S104 IMA Status:Approved IMA 1977 Locality:Old Lout mine, Ouray, Colorado. USA. Name Origin:Named for the locality.Physical Properties: Color:gray. Density:7.11 Diaphaniety:Opaque Habits:Microscopic Crystals - Crystals visible only with microscopes., Bladed - Aggregates of thin lath-like crystals (e.g. kyanite)., Hardness:2 - Gypsum Luster:MetallicMore details...