Rio Tinto unearths rare octahedral-shaped white diamond at ageing Argyle diamond mine
Rio has dug up a rare octahedral-shaped diamond, one of the largest ever found at its Argyle mine.
At 35 years of age, Rio Tinto’s Argyle diamond mine is nearing the end of its operating life but the massive Kimberly mine is still capable of producing some special gems.
Rio’s latest find is a rare octahedral-shaped white diamond which, at 28.84 carats, is one of the biggest ever found at the lucrative diamond mine.
The stone, named Argyle Octavia for its shape, won’t fetch nearly the prices of the fancy coloured pink and red diamonds that made the Kimberley mine’s renown and turned it into one of the most lucrative in the world.
The Argyle Muse, a 2.28-carat fancy purplish-red diamond was estimated to have fetched $US10-$15 million at tender last year.
But Octavia is notable both for its size, shape and — as possibly one of the last standout gems produced by Argyle — could still fetch more than $500,000 when it goes on the block in Antwerp later this year.
John Calleija, founder and master of design at high-end fashion jeweller Calleija - and one of only few jewellers picked as one of Rio’s Select Ateliers for its pink diamond range - said the nostalgic impact of its appearance, near the end of Argyle’s life, could add a premium to its price.
“It’s so rare, and so amazing, with its perfect shape as well as size. The mine is famous for its pink diamonds, and to produce near the end, as its last hurrah, something so beautiful makes it very special,” he said.
Mr Calleija said most sizable diamonds would lose up to half of their carats when cut and polished, but Octavia’s size meant it could remain a 20 carat diamond when cut for the shop floor.
“Cut, I think it could easily fetch $US3 million ($4.2, perhaps even more than that. I’d love to get my hands on it, you’d surround it with Argyle pink diamonds and you could make something very special,” he said.
Argyle’s rich history is likely to come to a close next year as its economic reserves run down and Rio prepares to begin rehabilitation work at the east Kimberly mine.
Rio Tinto copper and diamond boss Arnaud Soirat said the latest discovery was testament to the quality of the mine.
“We are delighted with this discovery which is a testament to the extraordinary Argyle orebody that continues to deliver these miracles of nature, even as it nears the end of mine life,” he said.