adularia

Noun.  A variety of orthoclase feldspar found as colorless to white prismatic crystals in cavities in metamorphic rocks. Some specimens reflect a bluish sheen along crystal faces. This phenomenon is called ''adularescence'', and adularia with this property is called ''moonstone''. (See sanidine).

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This entry was last updated on RefTopia from its source on 3/20/2012.