Home Columbite
IV - Oxides
Crystal habit of Columbite Columbite

Name   Columbite
Chemistry   (Fe,Mn)(Nb,Ta)2O6
Hardness   6
Lustre   metallic
Colour   black
Streak   brown to black 
Density [g/cm3]   5.3 - 8.1
(Nb)  (Ta)
Crystal habit   orthorhombic, crystals (Nb) tabular prismatic, (Ta) prismatic
Cleavage, Fracture   [010] distinct, fracture conchoidal
other characteristics and occurrences   mixed crystals
niobite   (Fe,Mn)Nb2O6
tantalite (Fe,Mn)Ta2O6
massive, in pegmatites, rarely in alkali granites

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© 2004 Büro für angewandte Mineralogie · Dr. Stephan Rudolph · D-47918 Tönisvorst
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