Moonstone

1. n. A nearly pellucid variety of feldspar, showing pearly or opaline reflections from within. It is used as a gem. The best specimens come from Ceylon.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.