At 12.03 carats, the Blue Moon is the largest cushion-shaped fancy vivid blue diamond ever to appear at auction. It is mounted on a ring and has the top grading of fancy vivid blue. Sotheby’s gave the diamond a pre-sale estimate of $35 million to $55 million.
Auctioneer David Bennett called the Blue Moon the "highest price per carat" ever obtained for any kind of stone, and the diamond set a world record for any jewel at more than $4 million per carat.
The blue diamond stone was found in South Africa’s famed Cullinan mine in January 2014. The distinctive blue color in diamonds is attributed to trace amounts of the element boron in the crystal structure.
The Blue Diamond Tops the Graff Pink
Until recently, the auction record had been held for five years by the Graff Pink diamond, which British billionaire jeweler Laurence Graff bought for almost $46 million at another Sotheby’s auction in Geneva in 2010.
Graff paid 45.4 million francs — almost $46 million — for the diamond and quickly renamed it, the “Graff Pink.” The rare pink diamond is rectangular shaped, and weighs 24.78 carats. It is among less than two percent of the world’s diamonds categorized as “potentially flawless” because it needs repolishing.
Graff’s buying price of $46 million at the time topped a previous world record for the selling price of a jewel at auction.
In 2013, Sotheby’s auctioned a pink diamond called the “Pink Star” for $83.2 million, but the buyer ultimately defaulted on the payment. The stone remains in the auction house’s inventory.
Other Big Sales at Sotheby’s
At the November 11 Sotheby’s auction, royal jewels, colored gemstones, and designer pieces by Van Cleef & Arpels, Cartier, and Harry Winston were among 410 lots that found new owners, bringing in $139 million.
A fancy vivid purple-pink, pear-shaped diamond ring sold for 13.9 million Swiss francs — approximately $14 million — the second-highest lot of the night.
An 8.48 carat Burmese ruby and diamond ring that belonged to the late Maria-Jose, the last Queen of Italy reached just 5.2 million francs, surprising those in attendance that it failed to meet the reserve price set by the seller.
Of interest to history buffs, a Cartier diamond and pearl tiara that survived Germany’s sinking of the Lusitania cruise liner 100 years ago — along with its Canadian owner Marguerite Lady Allan — sold for $800,000 after heated bidding, doubling its estimate.
A 15.20 carat fancy orange-pink diamond pendant owned by former James Bond actor Sean Connery sold for more than 4 million francs, tripling its estimate.