The record per carat is $1,375,938 (£854,705), for a 7.03-carat fancy vivid blue modified rectangular brilliant-cut diamond sold at Sotheby’s, Geneva, Switzerland, on 12 May 2009.

The total which it sold for was given in Swiss francs = CHF 10,498,500 or £6,000,000 ($9,959,000). The diamond was cut from an original stone, which weighed 26.58 carats, discovered in the Cullinan mine in Gauteng Province of South Africa, the same mine that produced the largest rough diamond in the world, from which was cut the Great Star of Africa, which is part of the Crown Jewels.