The Gemstone

 “There is in them a softer fire than the ruby, there is the brilliant purple of the amethyst, and the sea green of the emerald – all shining together in incredible union. Some by their splendor rival the colors of the painters, others the flame of burning sulphur or of fire quickened by oil.”

 

~Pliny the Elder, on the opal gemstone

Andamooka Opalstone is a “naturally occurring opalised sandstone”. There is no human intervention in its material formation – it is classified as “Natural Australian Opal”. During the gemstone’s “opalization phase”, opal leaches into the surrounding sandstone and entirely opalises that surrounding material – not simply a portion – thereby creating a silica solution. Eventually, further evaporation of water takes place and opal is formed from the trapped silica solution.

The Andamooka Opalstone has been recognised by the South Australian Government as a unique “Precious Opal”, which naturally exhibits the play of colours and fire within. The South Australian Government’s Department of Primary Industry and Resources SA (PIRSA) examined the Gemstone in 1995 and during 2000-2001, in order to determine whether it belonged to an existing class of opal or it was a new precious gemstone.

PIRSA’s tests showed that the gemstone was precious opal, different to all other know types of opal. The “Opalstone” exhibited no trace whatsoever of any residues within the healed fissures of the stone. The Gemstone’s name, “Andamooka Opalstone”, was endorsed by PIRSA and the South Australian Government Department, Invest SA, in 2001 (see official announcement in Minerals SA).