Columbite-(Mg)
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-(Mg) is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula MgNb₂O₆.
It crystallizes in the orthorhombic crystal system (space group Pbcn). It is a member of the Columbite structural group.
IMA symbol Clb-Mg, IMA status: approved, named in 1963.