Meaning of thorianite


Pronunciation: (thôr'ē-u-nīt", thōr'-), [key]
— n.
  1. a rare mineral, mainly thoria, ThO, but also containing uranium, cerium, and other rare-earth metals, occurring in small, black, cubic crystals: notable for its radioactivity and used as a minor source of thorium.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.