Meaning of moonstone

moon•stone

Pronunciation: (mn'stōn"), [key]
— n.
  1. Also calleda semitransparent or translucent, opalescent, pearly-blue variety of adularia, used as a gem.
  2. any of several adularescent feldspars, as certain varieties of albite, labradorite, or oligoclase, used as gems.
  3. (not used technically) any milky or girasol stone used as a gem.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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