Christie’s Geneva auction on 28 May 2026 saw the 5.50‑carat Ocean Dream—a fancy vivid blue‑green diamond—fetch CHF 13.56 million ($17.3 million). The triangular cut, SI1 clarity and 5.50‑carat weight make it the largest known stone of its hue, a fact that drove the record price.
But the gem’s allure isn’t just its size—its blue‑green tint is a product of natural radiation that altered its crystal lattice, a rarity that few other colored diamonds share. Cut from an 11.70‑carat rough discovered in Central Africa in the 1990s, the stone was reduced to less than half its original mass to preserve the vivid hue. Christie’s noted the meticulous polishing that kept the color intact.
In May 2014, the same diamond sold at Christie’s Geneva for CHF 7.7 million (about $8.5 million). The jump to $17.3 million—almost a 100% increase—underscores the escalating demand for exceptional fancy colored diamonds and signals a new price ceiling for future sales.
The stone has also lived beyond auction rooms. In 2003, it was on display at the Smithsonian National Museum of Natural History as part of “The Splendour of Diamonds,” standing beside the De Beers Millennium Star and the Steinmetz Pink. That exhibition highlighted how rare colors can captivate both scientists and the public.
While the buyer remains anonymous, the sale is expected to set a new benchmark for fancy vivid blue‑green diamonds, prompting collectors to bid higher at future Christie’s events. The market will likely watch closely as other rare gems enter the auction house, ready to test whether the Ocean Dream’s price can be matched or surpassed.
The next auction cycle will see Christie’s announce a new catalog of colored diamonds; analysts predict that the Ocean Dream’s record will influence pricing strategies for upcoming sales, potentially inflating the value of similar stones.