Goldstone is a type of glass made with copper or copper salts in the presence of a reducing flame. Under normal oxidative conditions, copper ions meld into the silica to produce transparent bluish-green glass; when the reduced goldstone melt cools, the copper remains in atomic isolation and precipitates into small crystalline clusters. The finished product can take a smooth polish and be carved into beads, figurines, or other artifacts. The most common form of goldstone gives the illusion of being reddish-brown, although in fact that color comes from the copper crystals and the glass itself is colorless.
