n. a low-grade flint-like iron ore containing 20-30% iron
The Century Dictionary and Cyclopedia
n. In petrography, a name proposed by H. V. Winchell (1896) for cherty or jaspery rock, in places calcareous or quartzitic, associated with the hematites of the Masaba Range, Minnesota.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a variety of chert containing magnetite and hematite; mined as a low-grade iron ore
Word Usage
"All that land is filled with taconite, which is the stuff they turn into iron."