A billion-year-old black diamond, believed to be the world’s largest cut diamond, has sold for £3.16m ($4.3m). Named The Enigma, the 555.55 carat gem, which weighs about the same as a banana, had been expected to fetch more than £4.4m in the online action. Auctioneer Sotheby’s said “the buyer has opted to use cryptocurrency for […]
