Beads of Bali

Goldstone beads are synthetic glass that can be easily polished and carved. It is occasionally sold under the names "aventurine glass," "stellaria," and "sun sitara." 

The most popular form of goldstone is deep red in color and contains metallic copper crystals.  The "recipe" consists of melting together silica, copper oxide, and other metals that lead to the formation of elemental copper.  The mixture is then sealed to avoid exposure to air but kep under heat until metallic crystals precipitate.  Composition can be altered to create goldstone of many different colors.