Niobite, or columbite, is a complex mineral with chemical formula [(Fe, Mn)(Nb, Ta)2O6]. It is orthorhombic and may be found in massive or granular form, or more rarely as well developed black crystals with a dull metallic lustre. It has the same composition and crystal symmetry as tantalite and the two are often considered a semi-singular mineral series, often referred to as coltan (for columbite-tantalite). In this specimen irregular black crystals are interspersed in a quartzitic pegmatitic matrix. Niobite is an ore for extracting niobium and tantalum, elements of essential use in various corrosion-resistant metal alloys. The origin of this specimen is Pennington county in South Dakota, USA. Actual width is 80 mm.