Rio Tinto’s own data show that the prices for their Argyle pink diamonds have risen 500% since 2000, though it won’t reveal the specific amount bidders have paid at any of its tenders.
But industry insiders know. Olya Linde, a partner at Bain & Co. in Moscow who studies metals and mining, says pink diamonds go for about $1 million to $3 million a carat.
It’s easier than ever to know the true value because, as West says, “we’re in the information age, and people find out what is really rare and what isn’t.”
Theories about the reason for the spike in prices vary, but Linde thinks it has to do with a concerted marketing effort by Argyle to promote itself as the “gold mine,” if you will, of pink diamonds.
Jewelers prize the Argyle “name-brand” stones even more than similar-quality gems from mines in Russia or South Africa. Each Argyle pink diamond comes with a certificate of authenticity.
Rio Tinto’s tenders are legendary as well, with stops in Perth, Singapore, London, and New York before bids close. They’re shrouded in secrecy as interested buyers place a sealed bid, and the winner is notified at the tender deadline.
There’s also the role of pop culture. Ben Affleck proposed to Jennifer Lopez in 2002 with a 6.10-carat fancy intense pink diamond from Harry Winston, setting off a trend in colored diamonds.
In general, says Sotheby’s jewelry specialist Quig Bruning, success begets more success in the diamond industry. “You have a couple of stones that sell for really big numbers who get a lot of attention,” he says.
The CTF Pink Star, an oval 59.60-carat mixed-cut Fancy Vivid Pink diamond mined by De Beers, set the world auction record for any diamond or jewel when it sold for $71.2 million at Sotheby’s Hong Kong in April 2017.
In 2018 the 18.96 Pink Legacy sold for $50 million at Christie’s auction house, breaking the world record for price paid per carat for a pink diamond at auction.