| n. | 1. | (Min.) A mineral of a black color, submetallic luster, and high specific specific gravity. It is a niobate (or columbate) of iron and manganese, containing tantalate of iron; - first found in New England. |
| Noun | 1. | columbite - a black mineral that is an ore of niobium and tantalum Synonyms: niobite |