Ocean Dream Blue-Green Diamond Sells for $17.3 Million at Christie's Geneva Auction

A 5.5-carat triangular-cut diamond billed as the largest fancy vivid blue-green diamond known to exist sold for $17.3 million on Wednesday, Christie's said. The auction house called it a record price for a stone of its kind sold at auction.

The "Ocean Dream," the standout lot at Christie's Geneva jewelry sale, was found in Central Africa in the 1990s. The price easily topped the presale estimate of 7-10 million francs (around $9-13 million).

Rahul Kadakia, president of Christie's Asia Pacific, said an unspecified private client bought the stone. It took about 20 minutes to sell, a sign of strong interest.

The price more than doubled the roughly $8.5 million the gem fetched at Christie's in 2014. That stone had appeared among rare colored diamonds at the Smithsonian Splendour of Diamonds Exhibition in 2003.

"A stellar result worthy of the world's rarest blue-green diamond," Tobias Kormind, managing director of online jeweler 77 Diamonds, said in a statement.

Christie's said the "Ocean Dream" weighs 9.4 grams and includes a ring mount set with sculpted rock crystal, round diamonds and pink diamonds.

On Tuesday, a 6-carat fancy vivid blue diamond failed to sell at Sotheby's Geneva auction. The auction house said the rare stone from South Africa's Cullinan mine carried a presale estimate of 7.2 million to 9.6 million francs ($9.2 million to $12.3 million).

"Although the diamond didn't find a buyer during the auction, we are now in conversations with several interested parties and are confident that it will find a new home soon," Sotheby's said in a statement.

Both houses say collectors show growing interest in rare colored diamonds, which represent only a fraction of all diamonds mined worldwide.

Christie's and Sotheby's have sold high-profile diamonds over the years. In 2023, an exceptionally rare blue diamond weighing 17.61 carats brought $43.8 million at a Christie's Geneva auction. In 2018, the auction house sold the "Pink Legacy" diamond for more than $50 million.