Largest blue diamond set to fetch US$48 million at Sotheby’s Hong Kong auction

A 15-carat De Beers Cullinan Blue diamond will go under the hammer at Hong Kong's Sotheby's in April 2022. The diamond is rare in terms of size, colour and cut, and has been graded as a Fancy Vivid Blue by the Gemological Institute of America (GIA). It is the largest and most valuable blue diamond ever to go on the block and is expected to fetch over US$48 million.