General Information:
Chemical Formula:
(Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6
Physical Properties:
Cleavage:
None
Color:
brownish black, dark brown, or black.
Density:
4.69 - 4.79, Average = 4.74
Diaphaniety:
Subtranslucent to Opaque
Hardness:
4-4.5 - Between Fluorite and Apatite
Luster:
Vitreous - Resinous
Streak:
grayish brown
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