The 15.10-carat "De Beers Blue" came within a whisker of setting a new world record for the priciest vivid blue diamond ever sold at auction. The hammer price of $57,471,960 at Sotheby's Hong Kong last night was just short of the $57,541,779 achieved by the 14.62-carat "Oppenheimer Blue" at Christie's Geneva in 2016. The single-lot, […]