from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A black, red-brown, or colorless mineral, essentially (Fe, Mn)(Nb, Ta)2O6, the principal ore of niobium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A black mineral that is a mixed iron and manganese niobate and tantalate, and is the main ore of niobium and tantalum.
from the GNU version of the Collaborative International Dictionary of English
- n. 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.
from The Century Dictionary and Cyclopedia
- n. The native niobate (columbate) of iron, a mineral of black color and high specific gravity, crystallizing in the orthorhombic system.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a black mineral that is an ore of niobium and tantalum
columb(ium) + -ite1.(American Heritage® Dictionary of the English Language, Fourth Edition)