dioptase: Meaning and Definition of

di•op•tase

Pronunciation: (dī-op'tās), [key]
— n.
  1. a mineral, hydrous copper silicate, CuSiO&multiplydot;HO, occurring in emerald-green crystals.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.