(IDEX Online) - Gem Diamonds has recovered its third +100-ct diamond of the year at its Letseng mine, in Lesotho.But it's still leaves the UK-based miner at well below its long-term average of eight +100-ct recoveries a year.The latest find is a 101.96-ct Type IIa diamond. Gem did not provide further details.In July it recovered a 163.91-ct yellow diamond and in March it recovered of a 122-carat D color Type II white diamond.Letseng, known as the highest dollar per carat kimberlite diamond mine in the world, saw average prices fall 22 per cent in the six months to 30 June, from $1,765 to $1,373.The mine is 70 per cent owned by Gem and 30 per cent by the Lesotho government.Pic courtesy Gem Diamonds