aventurine

n. [ F. aventurine: cf. It. avventurino. ] 1. A kind of glass, containing gold-colored spangles. It was produced in the first place by the accidental (par aventure) dropping of some brass filings into a pot of melted glass. [ 1913 Webster ]

2. (Min.) A variety of translucent quartz, spangled throughout with scales of yellow mica. [ 1913 Webster ]

Aventurine feldspar, a variety of oligoclase with internal firelike reflections due to the presence of minute crystals, probably of hematite; sunstone. [ 1913 Webster ]