[ moon-stohn ]

  1. Also called precious moonstone. a 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.

  1. (not used technically) any milky or girasol stone used as a gem.

Origin of moonstone

First recorded in 1625–35; moon + stone

Words Nearby moonstone Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use moonstone in a sentence

  • She only once alluded to the matter of the moonstone, and that was in the way of forbidding any present mention of it between us.

    The Moonstone | Wilkie Collins

British Dictionary definitions for moonstone


/ (ˈmuːnˌstəʊn) /

  1. a gem variety of orthoclase or albite that is white and translucent with bluish reflections

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012