Sotheby’s Expecting Over $48-Million For 15-Carat Cullinan Blue, The Largest Blue Diamond At Auction

Sotheby’s is set to auction the De Beers Cullinan Blue Diamond in April during its Hong Kong Luxury Week sales, starting at an estimate of $48-million. The 15.10-carat step-cut diamond is the largest vivid blue diamond ever to appear at auction and the largest internally flawless step-cut vivid …