The uncut 404-carat stone named the “4 de Fevereiro” discovered in Angola in February 2016. The gem has been cut into a 163-carat D flawless diamond, (de Grisogono).

A 163-carat D flawless diamond, described as the largest ever put up for auction, will be unveiled in Hong Kong on Thursday.

‘D’ graded diamonds are colorless

The diamond, which will be unveiled by jewelry specialist de Grisogono, is cut from a 404-carat stone named the “4 de Fevereiro” that was discovered in Angola in February 2016. A team of diamond cutting specialists spent 11 months cutting and polishing the gem, which will be auctioned as a 163-carat stone in Geneva, Switzerland on Nov. 14.

After the unveiling, the diamond will be taken on a world tour, visiting London, Dubai and New York before the Geneva auction.

In 2015 a ‘perfect’ 100-carat flawless D diamond was sold at Sotheby’s New York for $22 million, including the buyer’s premium.

An uncut diamond the size of a tennis ball sold for $53 million Tuesday. British jeweler Graff Diamonds bought the 1,109-carat stone, the Lesedi La Rona, which was mined in Botswana in 2015.