(Sharecast News) - Gem Diamonds has recovered another diamond of more than 100 carats from its Letseng mine in Lesotho.The company said on Wednesday that it has recovered a 138 carat, top white colour Type IIa diamond.This marks the twelfth diamond of more than 100 carats this year and a record for Gem in terms of the number of diamonds of more than 100 carats recovered in a year. Last month, the group recovered a 100.5 carat, top white colour Type IIa diamond from Letseng.At 0935 BST, the shares were up 2.6% to 117p.