Columbite-(Fe) Locality: Minas Gerais , Southeast Region, Brazil ( Locality at mindat.org ) Size: 5.5 x 4.9 x 3.9 cm. A large, complete all-around cluster of two, lustrous, blocky, black, parallel-growth ferrocolumbite crystals from an unknown locality in Minas Gerais, Brazil. Ex. Charles Hansen Collection. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Columbite-(Fe)
Columbite, also called niobite, niobite-tantalite and columbate, with a general chemical formula of (FeII,MnII)Nb2O6, is a black mineral group that is an ore of niobium. It has a submetallic luster, a high density, and is a niobate of iron and manganese. Niobite has many applications in aerospace, construction and the medical industry. Dating columbite minerals is primarily completed by uranium–lead dating, a slow process. Columbite has the same composition and crystal symmetry (orthorhombic) as tantalite.
Intro adapted from Wikipedia (CC BY-SA).
Columbite-(Fe) is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe²⁺Nb₂O₆.
It crystallizes in the orthorhombic crystal system (space group Pbcn). It is a member of the Columbite structural group.
IMA symbol Clb-Fe, IMA status: approved, named in 1805.