A unique collection of 26 polished diamonds derived from a Lesotho Promise stone and which together weigh 224.11 carats, have been put up on display at Laurence Graff’s London showroom. The 603-carat Lesotho Promise is the 15th largest stone to be found so far. It took a team of 35 people to cut and polish it, to produce the 26 diamonds. In 2006, Graff bought the stone for $12.4 million in a tender floated by Gem Diamonds.