General Information:
Chemical Formula:
(Mn,Fe++)(Nb,Ta)2O6
Physical Properties:
Cleavage:
[010] Distinct, [100] Indistinct
Color:
brownish black or black.
Density:
5.28
Diaphaniety:
Opaque
Hardness:
6 - Orthoclase
Luster:
Sub Metallic
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