The De Beers Blue, an exceptional 15.10-carat fancy vivid blue diamond, sold for HK$451 million (around US$57.5 million) at Sotheby’s Hong Kong, making it among the priciest diamonds ever sold at auction.

The diamond, the largest of its kind ever to appear at auction, set a “significant new benchmark for the diamond market,” having achieved among the highest prices ever for diamonds of any colour in the open market, according to Sotheby’s. 

It beat pre-sale estimates of HK$380 million (around US$48 million).

A private collector represented by Wenhao Yu, chairman of Jewellery and Watches at Sotheby’s Asia, purchased the diamond via phone, besting four other bidders. 

“The sum of US$57,470,391 is a near tie with the current record-holder for a blue diamond, achieved in 2016 when The Oppenheimer Blue (14.62 carats), sold for US$57,541,779,” revealed the auction house.

Cut from a historical rough stone discovered in April 2021, the gem has re-emerged as the largest vivid blue diamond ever to appear at auction and the largest internally flawless step-cut vivid blue diamond that the Gemological Institute of America has ever graded. 

Blue diamonds of this importance are exceptionally rare, with only five 10-carat+ examples ever having come to auction. None of which have exceeded 15 carats, making the appearance of this flawless gem a landmark event in itself, according to Sotheby’s.