The closure of the Argyle mine in Rio Tinto to raise...

At 14.83 carats, the Spirit of the Rose is the largest vibrant purple-pink diamond to appear at auction. When the gemstone goes under the hammer at Sotheby’s in Geneva on November 11, it is expected to bring in CHF 21-35 million (USD 23-38 million).

The sale comes at a turning point in the production of pink diamonds. Last Tuesday was the final day of mining at Rio Tinto’s Argyle Mine in Western Australia, the only consistent source of pink diamonds, accounting for 90 percent of global supply.

The exact impact of the closure on the market remains to be seen, but as demand increases, further reductions in limited supply are likely to push rising prices even higher.

Pink diamonds, which were first discovered in India in the 17th century and whose color is believed to be due to the stress on the diamonds during their creation, are rare. Found today in two Alrosa mines in Russia – including the Yakutia site where the miner discovered the 27.85-carat pink rough from which the Spirit of the Rose was cut – they account for less than 0.001 percent of the company’s production volume out.

Argyle Pink diamonds are “usually small” but have “color strength,” says Patrick Coppens, general manager of sales and marketing for Rio Tinto’s diamond business. The gemstones make up 0.13 percent of the roughly 865 million carats of rough diamonds that have been mined since production began in 1983. “A full year of argyle pink diamonds over half a carat would fit in the palm of your hand,” says Coppens.

The mine’s rarest polished pinks are sold via sealed bids in the annual Argyle Pink Diamonds Tender, an invitation-only event for around 100 collectors, jewelry stores and diamond connoisseurs. The rest of the polished production is sold to 14 partners who supply 35 “selected studios”.

One of the six “hero” gemstones in this year’s 62-stone tender collection – the penultimate one – is the 2.24-carat purple-pink Argyle Eternity, the largest fancy, vibrant, round, brilliant diamond offered in the history of the tender .

The bids won’t close until December 2nd, but according to Coppens the interest is “very high” as the market recognizes the “finiteness of the supply and the rarity of argyle pink diamonds”.

“There are currently no other consistent sources of pink diamond, and even if another deposit of ore containing pink diamonds were discovered, it would take an average of 10 years for a mine to go from discovery to production,” he says.

Boodles, a selected Argyle studio, will be among the bidders. Last month, the British jeweler bought the largest and most expensive pink diamond in its history – a pear-shaped stone weighing more than 10 carats (pictured below) from the Williamson mine in Tanzania. The gem is expected to sell for around £ 3.5 million in a ring. The purchase came in response to strong interest: pink diamond jewelry accounted for 32 percent of Boodles’ sales over £ 100,000 between mid-June and mid-October, compared to 10 percent for the same period in 2019.

Michael Wainwright, CEO of Boodle, predicts “very high” prices for the latest Argyle diamonds. Overall, the price of the Argyle Pink Diamonds Tender has risen by more than 500 percent since 2000, according to Rio Tinto. “We’ll be willing to pay more for them because the brand is worth a lot,” says Wainwright.

Alisa Moussaieff, managing director of Moussaieff, says the mine has “marketed its products very, very well”. “At the moment, the name ‘Argyle’ is contributing to salability,” she says.

Graeme Thompson, Phillips’ Global Head of Jewelry, agrees that Argyle diamonds receive a premium based on brand awareness. But prices for pink in general have gone up: the auction house says they have increased 300 percent in the past decade and have doubled in the past five years.

According to Sotheby’s, five of the top 10 most expensive diamonds sold at auction are pink, including the record-breaking 59.60 carat CTF Pink Star that was sold by the Hong Kong auction house in 2017 for HK $ 553 million ($ 71.2 million ) was sold.

Rio Tinto announced in 2018 that the Argyle mine had sufficient reserves to produce diamonds by the end of 2020. According to Thompson, there has been a “surge in interest” in pink diamonds after coverage of the closure placed them “in front and in the center of the colored diamond” collector’s spirit “. Although this interest was global, the Asian market in particular is driving consumption. “Pink in Asia – obviously Hello Kitty is another thing to look at – is just a very, very popular color,” he says.

Jardin de Giverny, a necklace that can also be worn as a bracelet or ring and has a 19-carat light pink diamond as its centerpiece (pictured above), is one of two lots that Chinese jewelry designer Feng J designed for Phillips ‘Jewelery & Jadeite auction in Hong Kong on November 28th. It has an estimate of HK $ 20-30 million ($ 2.5-3.8 million).

According to Thompson, pinks are viewed as an “alternative investment”. “When 90 percent of the world [pink] Diamonds are not produced, one would expect that the demand would surely exceed the supply, and that should drive prices up even further, ”he says.