Meaning of hawk's-eye

hawk's-eye

Pronunciation: (hôks'ī"), [key]
— n.
  1. a dark-blue chatoyant quartz formed by the silicification of crocidolite, used for ornamental purposes. Cf. tiger's-eye (def. 1).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.