The De Beers Blue diamond was a massive 15.10-carat largest internally flawless step cut vivid blue diamond. The exceptionally rare diamond was sold at Sotheby's in Hong Kong after an eight minute long bidding from four expectant buyers. The Gemological Institute of America classified the jewel as fancy vivid blue and Sotheby's statement informed that only five gems over 10 carats have ever appeared at its auctions and none have ever been over 15 carats, making the appearance of this flawless gem a landmark event in itself. 

Graded by the Gemological Institute of America with a final price of $57,471,960, The De Beers Cullinan Blue just narrowly missed setting the record for the most expensive blue diamond ever to sell at auction. The De Beers Blue was a 39.35-carat rough precious stone when it was discovered by Petra Diamonds in April 2021 at its Cullinan mine in South Africa. In July, De Beers and Diacore bought the stone for $40.2 million, and Diacore manufactured the piece into the final polished. The De Beers Cullinan Blue diamond is bigger than the Oppenheimer Blue, a 14.62 carat stone that set the world record price for a blue diamond at auction in May 2016 when it sold for $57.5 million. In February, London’s Sotheby sold the Enigma, the largest cut diamond ever to come to auction at 555.55 carats for £3.16 million.