Christie's said on May 13, 2026, that the Ocean Dream diamond had sold in Geneva for $17 million, a price that established a new auction record for a blue-green diamond. The sale placed one of the rarest colored stones ever handled by the house back in the spotlight, where collectors were bidding not just on size and beauty but on a combination of provenance, color and scarcity that very few gems can match.
The stone is 5.5 carats and was described by Christie's as the largest blue-green diamond ever recorded. The auction house said the gem was extracted from a mine in Central Africa in the 1990s and later cut from a rough stone weighing 11.70 carats. Christie's also said the Smithsonian Institution had listed it among the world's eight rarest diamonds, a distinction that helps explain why the jewel has remained so closely watched over the years.
Max Fawcett, Christie's global head of jewellery, stressed how unusual it is to find a stone of this color and size. He noted that green diamonds are extremely rare even when they weigh more than one carat and said a five-carat stone of this quality and color is remarkable. Christie's said the diamond is type Ia, which places it among the purest natural gems and adds another layer to its appeal for serious buyers.
The auction also showed how strongly the top end of the gemstone market responds to a stone with a clear history. Christie's said three clients from different parts of the world were bidding on the gem, but the winner chose to remain anonymous. That global interest matters because the market for colored diamonds depends on a small pool of buyers who understand both the aesthetic value and the long-term collectability of rare stones.
Ocean Dream is not new to the market. Christie's said it sold the same stone in 2014 for $8.5 million to a private Asian collector, meaning the latest sale roughly doubled the previous price. The diamond had also been exhibited at the Smithsonian's Museum of Natural History in Washington in 2003 as part of a show on exceptional gems, reinforcing its status as a stone that sits at the intersection of geology, museum history and luxury commerce.
Christie's said the stone had already proved its value on the market before the latest sale, having changed hands in 2014 for $8.5 million. It had also spent time in a museum setting in 2003, when it was shown at the Smithsonian's Museum of Natural History as part of a diamond exhibition. That museum history, plus the stone's unusual color and triangular cut, helps explain why the same gem can move between display, private ownership and auction room attention without losing its mystique.
That arc from rough stone to museum exhibit to record sale is part of why colored diamonds keep attracting attention. They are scarce, easy to identify and difficult to replace, which means their value can be driven by story as much as by sparkle. In this case, Christie's was selling a known object with a documented history, and that history helped turn a gem into an event.
