<p><strong>Noun</strong></p><ul><li>precious moonstone</li><li>a semitransparent or translucent, opalescent, pearly-blue variety of adularia, used as a gem</li><li>any of several adularescent feldspars, as certain varieties of albite, labradorite, or oligoclase, used as gems</li><li>any milky or girasol stone used as a gem</li></ul>