Stone Mania

Goldstone is also known as aventurine glass but this name is unpopular as it implies it is related to the mineral aventurine which it is not. 

Although it was known first, goldstone is now a common imitation of aventurine and also sunstone.  Goldstone is distinguished from the latter two by its coarse platelets of copper which are dispersed within the glass in an unnaturally uniform manner.  Goldstone is most commonly found in a golden brown colour and also deep blue which is known as blue goldstone.

The name aventurine comes from the Italian 'a ventura' meaning 'by chance'.  This came about at some point during the 18th century when goldstone was first discovered.  It is said that during the renaissance, glass-manufacturing monks in Venice accidentally spilt some molten copper into a vat of molten glass, when the mixture cooled, the copper crystallized which created this spangly or glittery effect. 

There is some controversy over whether goldstone should be referred to as a gemstone due to it being synthetic, however for the time being it is still considered as one.

The following link offers further reading on goldstone

http://en.wikipedia.org/wiki/Goldstone_%28gemstone%29