De Beers’ 15.10-ct Cullinan Blue Diamond Estimated At Over $48 Million

Sotheby’s will present the De Beers Cullinan Blue, one of the most valuable blue diamonds ever to be offered at auction. Estimated in excess of $48 million, this extraordinary 15.10-carat blue diamond has been recently cut from an exceptional rough stone discovered in April 2021.

It is 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 (GIA) 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.

The De Beers Cullinan Blue anchors Sotheby’s Hong Kong Luxury Week, and will be offered in a stand-alone, single lot live auction in late April 2022. Given the global interest in a treasure of this nature, the diamond will be showcased on a worldwide tour.

On view in Sotheby’s galleries in New York, it will then travel to cities including London, Dubai, Singapore, Shanghai, Beijing, Shenzhen, and Taipei.

Bruce Cleaver, CEO of De Beers Group, said: “This diamond ranks as one of the best De Beers has ever seen. 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.”

The diamond was discovered at the Cullinan Mine in South Africa in 2021, one of very few sources in the world for extremely rare blue diamonds.  Over the past year, De Beers has worked with its partner, Diacore, one of the most experienced master diamond cutters, to cut and polish the extraordinary rough diamond (pictured right) and bring The De Beers Cullinan Blue to life. Patti Wong, Chairman of Sotheby’s Asia, commented: “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. At a time of unprecedented demand for the finest, world-class, coloured diamonds, we are incredibly excited to bring to the market what is sure to become one of the most celebrated gems in the world.”

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