Auctions

On Wednesday 27th April at an evening sale at Sotheby’s in Hong Kong, The De Beers Cullinan Blue diamond was sold for a price of US$57.5m in eight minutes of bidding between four hopeful buyers.

A Magnificent and Spectacular Fancy Vivid Blue Diamond

Only five blue diamonds over 10 carats had ever been auctioned before and this extraordinary 15.10 carat step- cut blue diamond is the first to exceed 15 carats. The diamond also achieved the highest rankings in coloured diamonds by GIA (Gemological Institute of America) who categorised the jewel as "fancy vivid blue"; the top colour grading, awarded to no more than 1% of blue diamonds submitted to the world’s foremost grading organisation. 

It was discovered in April 2021 by Petra Diamonds in the famous Cullinan mine in South Africa, which yields not only most of the blue diamonds that are unearthed, but produced the largest diamond ever discovered in 1905, The Cullinan Diamond. The two largest stones cut from this historic rough diamond, which was given to Edward VII for his 66th birthday, are part of the Crown Jewels (the Great Star of Africa, or Cullinan I, is in the Sovereign's Sceptre with Cross, and the Second Star of Africa, Cullinan II, is mounted in the Imperial State Crown), while seven other major diamonds from it are owned by Her Majesty who inherited them from her grandmother. De Beers purchased the 40 carat rough diamond with Diacore, one of the most experienced diamond cutters, who then cut and polish the rough diamond into this exceptional step-cut gemstone.

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Blue diamonds are natural diamonds that form in the earth’s crust over billions of years, the blue colour comes from traces of boron in the diamond’s carbon composition. Blue diamonds are the rarest of fancy colour diamonds, except for red diamond and the bluer the intensity – the higher the value. The Hope Diamond, in the Smithsonian Institute in Washington, is one of the most famous blue diamonds. Laurence Graff bought the Wittelsbach blue diamond in 2007 and caused a furore in the jewellery world, as he recut it slightly to remove flaws and increase its colour grading from fancy deep greyish blue to fancy deep blue.