from
The Collaborative International Dictionary of English v.0.48
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.
[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]