TANTALITE
tantalite
(noun) a mineral consisting of tantalum oxide of iron and manganese that occurs with niobite or in coarse granite; an ore of tantalum
Source: WordNet® 3.1
Etymology
Noun
tantalite (plural tantalites)
(mineral) A dark-brown mineral that is an ore of tantalum and niobium, of the chemical formula (Fe, Mn) Ta2O6.
Source: Wiktionary
Tan"ta*lite, n. Etym: [Cf. F. tantalite.] (Min.)
Definition: A heavy mineral of an iron-black color and submetallic luster.
It is essentially a tantalate of iron.
Source: Webster’s Unabridged Dictionary 1913 Edition