Columbite - Wikipedia
Columbite, also called niobite, niobite-tantalite and columbate [(Fe, Mn)Nb 2O 6], is a black mineral group that is an ore of niobium. It has a submetallic luster and a high density and is a niobate of iron and manganese. This mineral group was first found in Haddam, Connecticut, in the United States. It forms a series with the tantalum-dominant analogue ferrotantalite and one with the manganese-domin…
![](/images/whatsappp.png)