/ Dictionary / Index C cassiterite: Meaning and Definition of Find definitions for: cas•sit•er•ite Pronunciation: (ku-sit'u-rīt"), [key] — n. a brown or black mineral, tin dioxide, SnO, that crystallizes in the tetragonal system; tinstone: the principal ore of tin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cassiterite (Thesaurus) Cassite Cassius Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language