After buying 8.2 percent in Gem Diamonds over the past two months, Laurence Graff has been working at increasing this stake, He recently brought its 8.2 percent stake to 9 percent, as reported by Industry Website. The shares of Gem Diamonds had spiraled after it issued a profit warning in November. %% Graff made further purchases from the company recently, buying another rare diamond from the company – a 478-carat rough Leseli la Letseng diamond, profiled as the 20th-largest rough diamond ever mined, from Gem Diamonds. Graff bought the rough for $18.4 million. His association with the company has been prevailing over some time, as he bought various exceptional stones from Gem Diamonds, including the 603-carat Lesotho Promise and the 493-carat Letseng legacy.