Letseng diamond mine
| Location | |
|---|---|
  Letšeng Diamond Mine | |
| Country | Lesotho |
| Coordinates | 29°0′01″S 28°51′43″E / 29.00028°S 28.86194°E |
| Production | |
| Products | diamonds |
| Type | diamond |
The Letšeng Diamond Mine, found in the landlocked Southern African kingdom of Lesotho, is owned by Gem Diamonds, Ltd. and the government of Lesotho, at an elevation of 3,100 m (10,200 ft) it is the world's highest diamond mine.
Production
[edit]It is characterised by extremely low grade ore (less than 400 milligrams (2 carats)/hundred tons) and is known for producing huge diamonds, having the highest percentage of large diamonds (greater than 2 grams (10 carats)), giving it the highest dollar value per carat of any diamond mine. The world average is roughly US$81 per carat, while Letšeng averaged over US$1,894 per carat for the first six months of 2007.[1]
Unusual for Africa, and due to the elevation, temperatures at the mine drop to -20 °C, and snowfalls are common in winter.
Geography
[edit]Climate
[edit]Letšeng has an alpine tundra climate (Köppen: ET) bordering on a dry-winter subarctic climate (Dwc). This means that Letšeng has a chilly climate with fairly cool temperatures throughout the year, even for Lesotho, and snowfalls can happen as well. The average annual temperature is 5.2 °C (41.4 °F), the average annual high temperature is 10.4 °C (50.7 °F) and the average annual low temperature is 0.1 °C (32.2 °F). The warmest month, January, has an average temperature of 9.8 °C (49.6 °F) and an average high temperature of 14.8 °C (58.6 °F). The coldest month, June, has an average temperature of −0.1 °C (31.8 °F) and an average low temperature of −5.5 °C (22.1 °F). June is the only month with an average temperature below freezing, although the average temperature of July is exactly 0 °C (32 °F).
Letšeng has an average annual precipitation of 881 millimetres (34.7 in). However, like most of Lesotho and South Africa, this is not evenly distributed throughout the year. Letšeng has a wet season with abundant rainfall from October to March and a dry season with less precipitation from May to August - the coldest time of year. In terms of precipitation April and October serve as transitions between the wet and dry seasons. January is the wettest month, receiving 133 millimetres (5.2 in) of precipitation on average, while July is the driest month, receiving only 8 millimetres (0.31 in) of precipitation on average.
| Climate data for Letšeng-la-Terae | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Mean daily maximum °C (°F) | 14.8 (58.6) | 14.5 (58.1) | 12.2 (54.0) | 10.6 (51.1) | 7.7 (45.9) | 5.4 (41.7) | 5.4 (41.7) | 6.8 (44.2) | 9.9 (49.8) | 11.2 (52.2) | 12.6 (54.7) | 13.7 (56.7) | 10.4 (50.7) |
| Daily mean °C (°F) | 9.8 (49.6) | 9.7 (49.5) | 7.7 (45.9) | 5.1 (41.2) | 2.0 (35.6) | −0.1 (31.8) | 0.0 (32.0) | 1.5 (34.7) | 4.6 (40.3) | 6.0 (42.8) | 7.5 (45.5) | 8.9 (48.0) | 5.2 (41.4) |
| Mean daily minimum °C (°F) | 4.8 (40.6) | 4.9 (40.8) | 3.3 (37.9) | −0.3 (31.5) | −3.6 (25.5) | −5.5 (22.1) | −5.3 (22.5) | −3.8 (25.2) | −0.6 (30.9) | 0.8 (33.4) | 2.5 (36.5) | 4.1 (39.4) | 0.1 (32.2) |
| Average precipitation mm (inches) | 133 (5.2) | 119 (4.7) | 120 (4.7) | 67 (2.6) | 20 (0.8) | 10 (0.4) | 8 (0.3) | 24 (0.9) | 57 (2.2) | 89 (3.5) | 115 (4.5) | 119 (4.7) | 881 (34.5) |
| Source: Climate-data.org[2] | |||||||||||||
Significant diamond finds
[edit]Lesotho Promise
[edit]On 4 October 2006 the 120.6 grams (603 carats) white diamond, the Lesotho Promise was unearthed, which until the January 2018 discovery noted below was the largest reported find this century; at the time it was found it was the 15th largest diamond ever found. The stone is of an exceptional colour, rated D, the top colour for diamonds.
Lesotho Brown
[edit]Previously the largest diamond found at Letšeng was the 120.2 grams (601 carats) Lesotho Brown, recovered in 1967.
Letšeng Legacy
[edit]On 13 September 2007 Gem Diamonds, Ltd. announced that it had found a 98.654 grams (493.27 carats) diamond, making it the 18th largest diamond ever found. It was sold to the Graff-SAFDICO partnership for $10.4 million.[1][3]
Star of Lesotho
[edit]In 2004, Gem Diamonds, Ltd. found a large diamond of 24.6 grams (123 carats).[4]
Leseli La Letšeng
[edit]On 21 September 2008 Gem Diamonds, Ltd. announced that it found a 95.6 grams (478 carats) diamond of high quality, making it the 20th largest diamond ever found. It is a type II D colour, with potential to yield a 30 grams (150 carats) cut stone. Chief executive Clifford Elphick said: "Preliminary examination of this remarkable diamond indicates it will yield a record-breaking polished stone of the very best colour and clarity, and has no inclusions visible in its rough form."[5][6] [7]
November 2010
[edit]The discovery of two large rough white diamonds was announced in November 2010.[8] They weighed 39.2 grams (196 carats) and 36.8 grams (184 carats).[9]
Lesotho Legend
[edit]In January 2018 Gem Diamonds announced the largest diamond yet discovered at Letšeng, a Type IIa D color stone measured at 182 grams (910 carats).[10] It sold in March 2018 for $40 million.[11] The same year a light brown diamond of 357.61 carats was discovered.
Letšeng Star
[edit]In August 2011 a diamond of 110 grams (550 carats) was found.
Letšeng Dynasty and Letseng Destiny
[edit]In May and July 2015, the discovery of two large diamonds was announced : the Letšeng Destiny of 62.8 grams (314 carats) and the Letšeng dynasty of 71.4 grams (357 carats).[12]
See also
[edit]References
[edit]- ^ a b "Big diamond discovery in Africa". Finance 24. Fin24.com. 13 September 2007. Retrieved 13 September 2007.[permanent dead link]
- ^ "Climate: Letšeng-la-Terae". Retrieved 26 April 2015.
- ^ Golan, Edhan (15 November 2007). "SAFDICO Pays $10.4M for 493 Carat Letšeng Legacy Diamond". International Diamond Exchange. Retrieved 15 January 2018.
- ^ "Star of Lesotho". Archived from the original on 12 October 2008. Retrieved 14 April 2008.
- ^ "menafn.com, World's 20th largest rough diamond found in Lesotho". Archived from the original on 12 February 2012. Retrieved 22 September 2008.
- ^ news.bbc.co.uk, Massive diamond found in Lesotho
- ^ "Lesotho mine yields one of world's largest diamonds". 21 September 2008. Retrieved 21 September 2008.
- ^ "Mining Journal - Gem recovers another large diamond from Letšeng". Retrieved 10 November 2010.[dead link]
- ^ "Mining Journal - Gem sells diamonds for US$22.7 million". Archived from the original on 4 December 2010. Retrieved 28 November 2010.
- ^ "Gem Diamonds | Investors | Press release: Board changes". Archived from the original on 15 January 2018. Retrieved 15 January 2018.
- ^ Gibbs, Alexandra (13 March 2018). "'The Lesotho Legend': The fifth-largest gem diamond in history sells for $40 million". CNBC. Retrieved 29 March 2021.
- ^ "Gem Diamonds | About us | Our Diamonds". Archived from the original on 24 January 2019. Retrieved 23 January 2019.