A rare blue-green diamond known as “Ocean Dream” sells for more than $17 million at Christie’s auction in Geneva. Christie’s says the 5.5-carat triangular-cut stone, described as the largest “fancy vivid blue-green” diamond known to exist, is the standout piece at the sale and ultimately fetches more than 13.5 million Swiss francs, equivalent to about $17.3 million. Multiple outlets report the same final price and characteristics, including the diamond’s cut and the description of its coloration and rarity.

CBS News adds that the diamond was found in Central Africa in the 1990s. Other reporting also says the stone is extracted from a mine in Central Africa, aligning with that timeframe. The accounts focus on the diamond’s sale result and its advertised status as an exceptionally large blue-green diamond, as well as its origin in Central Africa before the stone reaches the auction market. The reports do not name a buyer.