A Rare 15-Carat Blue Diamond Just Sold for $57.5 Million at a Sotheby's Auction
Sotheby's is constantly auctioning off incredible finds, including a rare gem rumored to be from outer space and an original print of the U.S. constitution. One of the auction house's latest marvels, however, is an incredibly valuable blue diamond that was originally projected to sell for $48 million in February. When the massive bauble came to auction in Hong Kong on Wednesday, however, it prompted an eight-minute-long bidding war; the winner, an anonymous buyer on the telephone, took it home for a whopping $57.5 million, reports CNN—$10 million over its projected selling price.
At 15.10 carats, the gem, which has been coined the "De Beers Cullinan Blue," is the biggest vivid blue diamond ever to appear at auction. According to the Gemological Institute of America, the diamond was given the highest rankings by which the quality of a colored diamond is judged. The GIA stated that it's "the largest internally flawless step cut vivid blue diamond" to be appraised by them. It was categorized as "fancy vivid blue,"—the highest possible color grading—which has been given to no more than one percent of blue diamonds reviewed by the institute.
Additionally, the exceptionally rare gem is one of five diamonds over the 10-carat mark that have ever come to auction. "Blue diamonds of any kind are rare on the market, but this is the rarest of the rare," says Patti Wong, chairman of Sotheby's Asia, in a press statement. "Nothing of remotely similar calibre has appeared at auction in recent years."
The diamond was cut from a 39.34 carat piece of rough mined at the Cullinan mine in South Africa, Forbes reports. That same mine has produced many valuable gems in the past and is considered to be the world's primary source of rare blue diamonds.