Qitianlingite

General Information:
 Chemical Formula:
Fe++2Nb2W++++++O10
 Composition:
(Molecular Weight = 641.35 gm)
Niobium 28.97 % Nb
Iron 17.42 % Fe
Tungsten 28.67 % W 
Oxygen 24.95 % O 
 Empirical Formula:
Fe2+2Nb2WO10
 IMA Status:
Approved IMA
Physical Properties:
 Color:
black.
 Density:
6.42
 Diaphaniety:
Opaque
 Hardness:
5.5 - Knife Blade
 Luster:
Sub Metallic
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