The "Ocean Dream," the largest blue-green diamond on record, sold at Christie's Geneva auction for US$17 million on May 13, 2026, setting a new benchmark for blue-green diamonds worldwide [1, 2]. Weighing 5.5 carats, the triangular brilliant-cut gem is prized for its rare vivid blue-green color, large size, and exceptional clarity. It is classified as a Type Ia diamond, among the purest natural diamonds [1, 2, 3].
The diamond was originally mined in Central Africa in the 1990s. At that time, it weighed between 11.17 and 11.70 carats in rough form; sources differ slightly on the exact original weight [2, 3]. It was later cut into its current 5.5-carat polished shape [2, 3].
In 2003, the Ocean Dream was exhibited at the Smithsonian Institution's Museum of Natural History in Washington DC as part of the "Splendor of Diamonds" exhibit, highlighting its prominence in the gem world [2, 3]. It was previously sold in 2014 to a private Asian collector for approximately US$8.5 to 9 million [2, 3].
The 2026 auction saw intense competition among three bidders from different parts of the world. The winning bidder chose to remain anonymous [1, 2]. Max Fawcett, global head of Christie's Jewellery, remarked, "It's very rare to find green diamonds, even over one carat. To find something in five carat of this quality and this colour is truly remarkable" [2].
There was some discrepancy in reporting about the auction price and the stone's original weight. While most sources confirmed the $17 million final price, one source noted the market expected $12.8 million but did not confirm the final figure [1, 2, 3]. Likewise, the rough stone's weight is reported as 11.17 or 11.70 carats depending on the source [2, 3].
The sale marks the latest chapter in the Ocean Dream's history, from Central African mine to museum exhibit to record-setting auction jewel. The next major display or sale event for the gem has not been announced as of today.
