Columbite Locality: Galiléia, Doce valley, Minas Gerais, Southeast Region, Brazil (Locality at mindat.org) WOW! This is an unusual pseudocubic crystal of columb — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Columbite
Also known as: Coltan ore (with tantalite).
The black iron-manganese niobate that gives niobium its alternate name 'columbium' — a dense, submetallic ore mineral.
Intro adapted from Wikipedia (CC BY-SA).
Columbite is a mineral group, with the chemical formula (Fe,Mn)Nb₂O₆.
It crystallizes in the orthorhombic crystal system.
Key properties: Mohs hardness 6–6.5; typically black or brown.
Collections: Metals & Native Elements, Collector Favorites.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data and a Wikipedia introduction — a full written entry hasn’t been published yet.
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