( 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.
( 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.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012