Ourayite

General Information:
 Chemical Formula:
Pb4Ag3Bi5S13
 Composition:
(Molecular Weight = 20815.77 gm)
Silver 12.96 % Ag
Bismuth 41.16 % Bi
Lead 29.86 % Pb
Sulfur 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:
Metallic
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