Rare pink diamond expected to fetch $31.8m at Hong Kong auction

The Williamson Pink Star is the second-largest, internally flawless "fancy vivid pink" diamond to ever go under the hammer. PHOTO: AFP

HONG KONG - A rare pink diamond was expected to fetch more than £20 million (S$31.83 million) at an auction on Hong Kong on Friday, The Guardian reported.

The Williamson Pink Star is the second-largest, internally flawless "fancy vivid pink" diamond to ever go under the hammer.

Cushion-shaped and 11.5-carat in weight, its name pays homage to two other huge pink diamonds: the 59.60-carat, mixed-cut, oval Pink Star diamond that sold for US$71.2 million (S$101.83 million) at an auction in 2017 and a 23.60-carat diamond dubbed the Williamson stone, which was gifted to the late Queen Elizabeth II as a wedding gift by the Canadian geologist and royalist John Thorburn Williamson in 1947.

Williamson owned the mine in Tanzania where both the Williamson Pink Star and Williamson stone were discovered.

Pink diamonds are a mystery in the gemological world. A rare colour for a diamond, it is unclear how they are formed geologically.

Among the most valuable of all the coloured diamonds, the size and flawless character of the Williamson Pink Star further put it into an even smaller subset of the rarest of gems.

Join ST's Telegram channel and get the latest breaking news delivered to you.