Pink diamond expected to fetch more than £20m at Sotherby

Williamson Pink Star, the second largest, internally flawless “fancy vivid pink” diamond ever to appear at auction, is expected to sell for more than £20m when it goes under the hammer at Sotheby’s in Hong Kong on Friday.

Report informs, citing The Guardian, that the 11.15-carat, cushion-shaped diamond, known as the Williamson Pink Star, is named after two other huge pink diamonds: the 59.60-carat, mixed-cut, oval Pink Star diamond that sold for a record $71.2m at auction in 2017, and the Williamson stone, a 23.60-carat diamond given to the late Queen Elizabeth II as a wedding gift by the Canadian geologist and ardent royalist John Thorburn Williamson in 1947.

Pink diamonds are particularly rare among coloured diamonds and no one quite knows exactly how they become pink geologically.