The origin of modern Aventurine Glass or Goldstone is generally thought to have begun in Murano, Italy - the Venetian Island still famous for its glass - during the 17th century.
It became known as "Aventurine glass" from the Italian for "by accident", as it was thought to have been created by the accidental spillage of copper filings into a vat of molten glass.
However artefacts of a material similar to modern goldstone have been excavated in Iran, dating from the 12th-13th century.
Unlike brown goldstone, which gets its sparkle from copper particles, the blue version substitutes cobalt, giving the resulting glass a silvery-blue glitter.
The choice of blue stones and the Swarovski "sapphire" crystals make this gorgeous necklace a good choice for those born in September, or with the zodiac sign Virgo, whose traditional birthstone is the Sapphire and whose birthstone colour is deep blue.