- Also called precious moonstone. a semitransparent or translucent, opalescent, pearly-blue variety of adularia, used as a gem.
- any of several adularescent feldspars, as certain varieties of albite, labradorite, or oligoclase, used as gems.
- (not used technically) any milky or girasol stone used as a gem.
Origin of moonstone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for moonstone
"I am going to read 'The Moonstone' out in the garden the whole afternoon," she replied.The Beth Book
You may discover so much by reading the "Moonstone," that monument of ingenuity and absurdity.Hieroglyphics
The opal and the moonstone are the gems most often figuring in these tales.The Myths and Fables of To-Day
Samuel Adams Drake
Nobody in Moonstone ever found what Wunsch's first name was.
The wickedness of Denver and of Chicago, and even of Moonstone, occupied her thoughts too much.
- a gem variety of orthoclase or albite that is white and translucent with bluish reflections