Columbite Article about Columbite by The Free Dictionary
columbite mineralogy Fe,MnCb,Ta2O6 An iron black mineral with a submetallic luster that crystallizes in the orthorhombic system the chief ore mineral of niobium columbium hardness is 6 on Mohs scale, and specific gravity is 5.4 6.5. Also known as dianite greenlandite niobite. Columbite from Latin columbium, an alternate






































