Collier's New Encyclopedia (1921)/Columbite

COLUMBITE. A mineral containing iron, columbium, and usually manganese and tantalum. Its formula is commonly given as (Fe, Mn) (Cb, Ta)₂O₆. Occurs as opaque orthorhombic crystals, dark brown or black in color; specific gravity about 6.0. The mineral is found in Colorado, Connecticut, Maine, North Carolina, South Dakota, Virginia, and in Norway, and is of interest because the element Columbium was first discovered in it by C. Hatchett, in 1802, the name being given because the mineral in which the metal was found came from America.