Rhodizite , Columbite-(Mn) Locality: Sahatany Pegmatite Field (Mt Bity (Ibity) area), Manandona Valley, Vakinankaratra Region , Antananarivo Province , Madagascar ( Locality at mindat.org ) Fine rhodizite specimens with rich color, excellent lustre, and sharpness of the crystal (which is 1.3 cm in height). 3.7 x 3.5 x 2.5 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Columbite-(Mn)
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-(Mn) is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mn²⁺Nb₂O₆.
It crystallizes in the orthorhombic crystal system (space group Pbcn). It is a member of the Columbite structural group.
IMA symbol Clb-Mn, IMA status: approved, named in 1892.