Photo: Richard Lyons courtesy South Australian Museum.
South Australia Museum opal exhibition, including the exhibition’s centerpiece, the Virgin Rainbow, is itself worth in excess of a million dollars and its refracting colours defy description.
We had to put the picture of the renown ‘Virgin Rainbow’ opal on this issue’s cover because it’s simply stunning.
It’s some distance for a lot of our readers but if you happen to have the opportunity to visit the South Australian Museum in Adelaide you’ll sure to be impressed with the superb collection of opals on view.(exibition closes spring 2016)
The Virgin Rainbow was found in 2003 and represents a belemnite fossil 63mm in length weighing 72.65 carats.
Opal formation began when South Australia’s inland sea acted as a breeding ground for plesiosaurs, the marine reptile equivalent of dinosaurs. As plesiosaurs died their bodies sank to the bottom of the sea. Later, after climate change transformed the area into an arid moon landscape, some of these skeletons became opalised fossils.
“In time this sparked the creation of opal mining communities in places like Coober Pedy, Andamooka and Mintabie, which have remained opal mining hubs to this day.
“It is ironic that in the most harsh of terrains the most beautiful of naturally occurring gems are now found.”
Australian opals, are composed of tiny silica spheres of certain sizes, stacked closely together, classified as Opal-A and are usually more stable than opals from other regions such as Ethiopia where the opals are referred to as hydrophane(meaning absorbs water like a sponge, due to an irregular structure which creates gaps).
Famous Australian opals include the Andamooka Opal a cut 203 carat stone presented to Queen Elizabeth II in 1954 & the Light of the World a rough 2268 carat black opal discovered in 1928, subsequently cut into a 252 carat gem.
All photos: courtesy South Australian Museum.