Ferrocolumbite

General Information: Chemical Formula:Fe++Nb2O6 Composition:(Molecular Weight = 337.66 gm)Niobium 55.03 % NbIron 16.54 % FeOxygen 28.43 % O  Empirical Formula: Fe2+Nb2O6 Environment:Pegmatites, and alluvial deposits. Locality:M'buye Mine, Rwanda. Name Origin:Named after its content of the element niobium, formerly called columbium and the Latin ferrium - "iron."Physical Properties: Cleavage:[010] Distinct Color:black or brownish black. Density:5.3 - 7.3, Average = 6.3 Diaphaniety:Translucent to opaque Habits:Massive - Granular - Common texture observed in granite and other igneous rock., Striated - Parallel lines on crystal surface or cleavage face., Hardness:6 - Orthoclase Luminescence:Non-fluorescent. Luster:Sub Metallic Streak:blackish brownMore details...