Huge diamond that’s ‘one of world’s best ever found’ expected to sell for £40m

An admirable diamond that is touted as “one of the world’s best ever found” is likely to be sell somewhere between £27 million and £40million.

The 17.61-carat blue diamond could become one of the most expensive stones ever sold by Christie’s at an auction in Geneva. 

The Bleu Royal is the top lot in a series of auctions to be held this month on the shores of Lake Geneva, including legendary items from the history of cinema, such as pearls worn by Audrey Hepburn and a Marlon Brando’s engraved watch.

‌The 17.61-carat stone is the largest flawless bright blue fancy gemstone ever offered for sale at auction. Set in a ring, it had been part of a private collection for 50 years.

‌Rahul Kadakia, the auction house’s international head of jewellery, told AFP: “It will be in the top 10 of Christie’s sales in terms of value.”

According to Mr Kadakia, many modern diamonds have been cut to enhance their colour. 

But in the case of the Bleu Royal, “the rough material itself was so rich that they were able to cut it in a classic brilliant faceting style. It ticks all the boxes – it really is the best in its class,” he said. 

Vivid blue fancy diamonds over 10 carats are rare. 

Since Christie’s was founded in 1766, only three such stones have been offered for sale, and all of them in the last 13 years. 

The Bulgari Blue sold for almost €14.7 million in 2010, the Winston Blue fetched €22.2 million in 2014 and the Oppenheimer Blue was acquired for $53.6 million in 2016.

Mr Kadakia added: “This part of the jewellery market is now subject to the same kind of appreciation as art.

“The market has seen the great rarity of these special stones and prices are now valued in the same way as they are for great paintings.”