De Beers Cullinan Blue Diamond Could Bring $48M at Auction

Sotheby’s will auction a stone described as “the largest vivid blue diamond ever to appear at auction” on April 27 in Hong Kong.

Sotheby’s estimates that it could bring $48 million.

The 15.1 carat step-cut blue was cut from a rough stone discovered in April 2021. It is “the largest internally flawless step cut vivid blue diamond that the Gemological Institute of America (GIA) has ever graded,” according to a press statement.

“This diamond ranks as one of the best De Beers has ever seen,” said Bruce Cleaver, CEO of De Beers Group. “It is extremely rare and unique, and as the Home of Diamonds, De Beers is pleased to join together with Sotheby’s to bring this diamond to the world.”

Only five blue diamonds over 10 carats have ever come to auction, Sotheby’s notes. Until now, none has exceeded 15 carats.

“Blue diamonds of any kind are rare on the market, but this is the rarest of the rare; nothing of remotely similar calibre has appeared at auction in recent years,” says Patti Wong, chairwoman of Sotheby’s Asia. “Hundreds of millions of years in the making, this extraordinary blue diamond is surely one of nature’s finest creations.”

The diamond comes from the Cullinan mine in South Africa.