‘Billionaires with everything except a red diamond’: Ultra-rich and gemstone buffs snoop Rio Tinto collection

A cohort of ultra-wealthy diamond enthusiasts filed discreetly into a top secret Perth location this week to make their bids for the final batch of rare Rio Tinto stones mined at the now-shuttered WA Argyle mine. While much of the population agonises over the cost of an ad-free Netflix subscription, others are mulling whether they should open their chequebooks for a pink, red, yellow or blue diamond, of which the highest calibre can fetch millions of dollars. The Rio Tinto tender is an invite only process open to about 100 individuals and companies. Some have a deep passion in gemology, while others are “billionaires with everything except a red diamond on their on their finger,” Rio’s Michelle Sherring says. The Rio sales and business development manager for its diamond division recounts that there’s been increased interest in the tenders, a process that usually “bucks the trend” of what’s happening in the broader economic environment. The entire collection comprises six so-called “masterpiece” collections, 39 single diamonds and seven curated “sets” of stones - all totting up to a tidy 45.44 carats. The “Fancy Vivid Yellow” diamond weighs in at 6.12 carats and is the largest in the collection. But it’s the colour and the clarity that can make a big difference. In 2024, an Argyle Phoenix 1.56ct Fancy Red — purportedly far rarer than a pink — fetched $US4.3 million at an auction in Geneva. And there’s also seemingly no concern from Rio’s diamond division about the meteoric ascent of lab grown alternatives. “Certainly there’s a place for a well-managed, lab grown industry. But when we’re talking about the 1 per cent, can’t-be-recreated- market. . .we see probably a greater correlation between what happens in the art space in terms of collectability,” Ms Sherring says. The stones are mostly from Rio Tinto’s closed Argyle mine with some from Diavik in Canada, and have already been showcased in Hong Kong. They will make their way to the diamond capital of Antwerp before bids close on October 20. The collection has been billed by Rio as its final tender.