Katoptrite

General Information:
 Chemical Formula:
(Mn,Mg)13(Al,Fe+++)4Sb+++++2Si2O28
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
black or red.
 Density:
4.56
 Diaphaniety:
Translucent to Opaque
 Hardness:
5.5 - Knife Blade
 Luster:
Metallic
 Streak:
red brown
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