RAPAPORT… A record blue diamond co-owned by De Beers far outstripped its presale estimate in a stand-alone sale at Sotheby’s in Hong Kong, garnering HKD 450.9 million ($57.5 million).
The step-cut, 15.10-carat, fancy-vivid-blue, internally flawless stone, called the De Beers Cullinan Blue, is the largest of its color to appear at auction. The stone sold to an unnamed buyer following a “prolonged, eight-minute battle between four contestants,” Sotheby’s said Wednesday.
The price achieved is a tie with the current record holder for a blue diamond, and also makes the stone the third most valuable diamond of any color to sell at auction, Sotheby’s explained. The stone had been expected to fetch up to $48 million.
“The De Beers Blue captivated me from the moment I laid eyes on it,” said Patti Wong, chairman of Sotheby’s Asia. “With its powerful vivid color, and breathtakingly beautiful cut, it is truly a once-in-a-generation stone, and quite simply the greatest blue diamond of its size I have ever seen during my 31-year career at Sotheby’s.”
Petra Diamonds discovered the 39.35-carat rough 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.
To date, only five blue diamonds weighing more than 10 carats have come to auction, none of which has exceeded 15 carats, Sotheby’s explained. Similar blue diamonds have also fetched high prices, including the Blue Moon of Josephine, a cushion-shaped, 12.03-carat, fancy-vivid-blue, internally flawless diamond that sold for $48.5 million at Sotheby’s Geneva in 2015. Meanwhile, the Oppenheimer Blue, a step-cut, 14.62-carat, fancy-vivid-blue, VVS1-clarity stone, garnered $57.5 million at a Christie’s Geneva sale in 2016.
Image: The 15.10-carat De Beers Cullinan Blue diamond. (Sotheby’s)