Biggest diamond ever to be sold fetches £25 million at auction

Experts are bitterly disappointed as they had expected the diamond to be sold for at least £12 million more.

The world's biggest diamond ever to be put up for sale at an auction fetched £25 million late on Tuesday. 

Called The Art of Grisogono, the 163.41-carat diamond - attached to an emerald and diamond necklace - was sold to an unnamed telephone bidder at the Christie's autumn jewel auction in Geneva, Switzerland. Experts, however, are bitterly disappointed as they had expected the diamond to be sold for at least £12 million more. 

Nonetheless, Rahul Kadakia, auctioneer and head of Christie's international jewels division, said that it was a record price for a D-colour diamond at an auction. D, according to gemologists, is the highest colour grade given to diamonds and indicates that the precious stone is absolutely colourless and therefore rare.

The diamond itself was cut from a 404 carat rough rock which was found in February of 2016 in Angloa's Lulo mines. Ten diamond-cutting specialists worked on the rough in New York after it was analysed in Antwerp.