aventurine, n. [F. aventurine: cf. It. avventurino.].
Aventurine feldspar, a variety of oligoclase with internal firelike reflections due to the presence of minute crystals, probably of hematite; sunstone.
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]
A variety of translucent quartz, spangled throughout with scales of yellow mica. [1913 Webster]