Neyite

General Information:
 Chemical Formula:
Pb7(Cu,Ag)2Bi6S17
 Composition:
(Molecular Weight = 3,398.66 gm)
Copper 2.80 % Cu
Silver 1.59 % Ag
Bismuth 36.89 % Bi
Lead 42.68 % Pb
Sulfur 16.04 % S 
 Empirical Formula:
Pb7Cu1.5Ag0.5Bi6S17
 IMA Status:
Approved IMA 1969
Physical Properties:
 Cleavage:
None
 Color:
lead gray, gray blue, yellow blue, or silver gray.
 Density:
7.02
 Diaphaniety:
Opaque
 Hardness:
2.5 - Finger Nail
 Luster:
Metallic
 Streak:
gray
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