According to the South Australian Museum, the Fire of Australia is valued at AU$900,000 and weighs an estimated 998 grams.
The gemstone, which is almost 5,000 carats and has a size comparable to two cricket balls, was discovered by Walter Bartram in 1946 in Coober Pedy, South Australia. It had remained in the possession of the Bartram family until now.
The museum acquired the Fire of Australia for AU$500,000 with support from the Federal Government, which provided AU$455,000 in funding through its National Cultural Heritage Account.
South Australian Museum collection manager Ben McHenry told Jeweller that although the owners had applied for approval to export the opal overseas, they had offered it to the museum at a “much-reduced value” in an effort to keep the gemstone in Australia.
“The Fire of Australia is the largest piece of high-quality light opal rough in existence,” McHenry stated.
“Ordinarily, it would have been cut up for the jewellery trade,” he said, adding, “Keeping it in its current form gives the museum the opportunity to display to its visitors just how magnificent opal in the rough can be.”
Commenting on the decision to sell the gemstone to the museum, Bartram’s son Alan explained it was important that the opal was preserved as a rough.
“Because it is a family piece, we were able to decide what to do with it; and we didn’t want to see it cut up in our lifetime,” he said.
The opal has been left in its original rough state – two faces have been polished –with the South Australian Museum describing it as the finest sample of its kind to be on public display.
The Fire of Australia was on loan for the South Australian Museum's Opals exhibition that ran from 25 September 2015 to 14 February 2016.
It will be on display in the museum’s foyer until 28 February 2017 before being placed in its permanent opal collection.
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