Letseng diamond mine

The Letseng diamond mine, found in the landlocked Southern African kingdom of Lesotho, is owned by Gem Diamonds, Ltd. and the government of Lesotho, and at an elevation of 3,100 m (10,000 ft) it is the world's highest diamond mine.ProductionIt is characterised by extremely low grade ore and is well known for producing huge diamonds, having the highest percentage of large diamonds, giving it the highest dollar value per carat of any diamond mine. The world average is roughly US$81 per carat, while Letseng averaged over US$1,894 per carat for the first six months of 2007.Unusual for Africa, and due to the elevation, temperatures at the mine drop to -20 °C, and snowfalls are common in winter.GeographyClimateLetseng has a tundra climate (ET, according to the Köppen climate classification), with an average annual precipitation of 881mm. This climate has chilly to cold temperatures throughout the year, with snowfalls.Significant diamond findsLesotho PromiseOn 4 October 2006 the 603 carat white diamond, the Lesotho Promise was unearthed, and is the largest reported find this century and the 15th largest diamond ever found. The stone is an exceptional colour, rated D, the top colour for diamonds.Lesotho BrownPreviously the largest diamond found at Letseng was the 601 carat Lesotho Brown, recovered in 1967.