General Information:
Chemical Formula:
(Mg,Fe++,Mn)(Nb,Ta)2O6
IMA Status:
Approved IMA 1963
Physical Properties:
Cleavage:
[010] Indistinct, [100] Indistinct
Color:
brownish black or black.
Density:
5.04
Diaphaniety:
Opaque
Hardness:
6.5 - Pyrite
Luminescence:
Non-fluorescent.
Luster:
Sub Metallic
Streak:
dark brown
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