Aventurine \A*ven"tu*rine\, 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.

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

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

Source: Webster's Revised Unabridged Dictionary (1913)