Dictionary
zir•con
Pronunciation: (zûr'kon), [key]—
n.
a common mineral, zirconium silicate, ZrSiO
4, occurring in small tetragonal crystals or grains of various colors, usually opaque: used as a refractory when opaque and as a gem when transparent.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.