Bartonite

General Information:
 Chemical Formula:
K3Fe10S14
 Composition:
(Molecular Weight = 1,124.69 gm)
Potassium 10.43 % K 
Iron 49.66 % Fe
Sulfur 39.92 % S 
 Empirical Formula:
K3Fe2+10S14
 IMA Status:
Approved IMA 1978
 Locality:
Coyote Peak diatreme, 16 miles SW of Orick, Humboldt Co. California.
Physical Properties:
 Cleavage:
[112] Distinct
 Color:
black brown.
 Density:
3.305
 Diaphaniety:
Opaque
 Hardness:
3.5 - Copper Penny
 Luster:
Metallic
 Streak:
black
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