Launayite

General Information:
 Chemical Formula:
Pb22Sb26S61
 Composition:
(Molecular Weight = 9,679.93 gm)
Antimony 32.70 % Sb
Lead 47.09 % Pb
Sulfur 20.21 % S 
 Empirical Formula:
Pb22Sb26S61
 IMA Status:
Approved IMA 1967
Physical Properties:
 Cleavage:
[100] Perfect, [001] Perfect
 Color:
lead gray.
 Density:
5.75
 Diaphaniety:
Opaque
 Hardness:
3.5-4 - Copper Penny-Flourite
 Luster:
Metallic
 Streak:
black
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