Magnocolumbite

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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