Though not a stone--or gold!--this manufactured "gemstone material" is known by many names: "aventurine glass," stellaria, gold star glass, monkstone or monk's gold.
 
Modern goldstone can be created either with copper flecks or with other metallic compounds such as cobalt, manganese or chromium oxide. These are used in goldstones made using colors (respectively) such as purple, blue and green.
 
Called the stone of ambition, goldstone is thought to assist in attaining goals. Some consider goldstone to be a symbol of ingenuity, ambition, and drive. It believed to reduce tension, revitalize the wearer and encourage a positive attitude.