Matura diamond: Meaning and Definition of

Ma'tu•ra dia'mond

Pronunciation: (mä'tur-u, mat'ur-u), [key]
— Jewelry. Jewelry.
  1. a zircon heat-treated to render it colorless: not a true diamond.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.