Aventurine

Aventurine is a translucent to opaque, massive variety of Quartz containing small inclusions of one of several shiny minerals which give the stone a glistening effect. The glistening effect of Aventurine is known as aventurescence. The color of the aventurescence depends on the mineral included in the stone. Mica inclusions give the give the stone a yellowish or silverish glitter or sheen. Goethite and Hematite inclusions give the stone a reddish or grayish glitter or sheen. Fuschite inclusions give the stone a greenish sheen.
Aventurine may be green, orange, brown, yellow, or gray. All colors may be used in jewelry, but the green type is by far the most desirable. Aventurine is cut and polished into cabochons and beads for jewelry, and is sometimes carved into ornamental figures.

Most Aventurine is Quartz, but some Oligoclase Feldspar exhibits aventurescence, and may also be called Aventurine. However, the term Feldspar must be added to the name to distinguish it from Quartz Aventurine. The more accepted term for Aventurine Feldspar is Sunstone.