diamond sells at auction for $57.73 million, it surpasses all previous records for price per carat.

Friday night in Hong Kong, a pink diamond sold for $57.73 million at auction, making it the most expensive diamond ever sold per carat.

At a Sotheby's auction, the 11.15-carat Williamson Pink Star diamond found a buyer. The auctioneer's commission is included in the $57.73 million price tag. The diamond's raw cost, excluding fees, is $49.9 million, or $4.475 million per carat. It was predicted to fetch around $21 million at auction.

According to Forbes, the Oppenheimer Blue diamond, which sold for a hammer price of $51.3 million and weighed 14.62 carats, or $3.5 million per carat, was the most expensive diamond ever sold per carat up to this point.

Tobias Kormind, managing director of De Beers, said, "This is an astonishing outcome, illustrating the endurance of premium diamonds in a fragile economy."