Letseng diamond mine
Location | |
---|---|
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, and at an elevation of 3,100 m (10,000 ft) it is the world's highest diamond mine.
Production
It is characterised by extremely low grade ore (less than 2 carats (400 mg)/hundred tons) and is known for producing huge diamonds, having the highest percentage of large diamonds (greater than 10 carats (2.0 g)), 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
Climate
Letšeng has a tundra climate (ET, according to the Köppen climate classification), with an average annual precipitation of 881 mm (35 in). This climate has chilly to cold temperatures throughout the year, with snowfalls.
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
Lesotho Promise
On 4 October 2006 the 603 carat (121 g) 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
Previously the largest diamond found at Letšeng was the 601 carat (120 g) Lesotho Brown, recovered in 1967.
Letšeng Legacy
On 13 September 2007 Gem Diamonds, Ltd. announced that it had found a 493.27 carats (98.654 g) 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
In 2004, Gem Diamonds, Ltd. found a large diamond of 123 carats (24.6 g).[4]
Leseli La Letšeng
On 21 September 2008 Gem Diamonds, Ltd. announced that it found a 478 carats (95.6 g) diamond of high quality, making it the 20th largest diamond ever found. It is a type II D colour, with potential to yield a 150 carats (30 g) 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
The discovery of two large rough white diamonds was announced in November 2010.[8] They weighed 196ct and 184ct.[9]
Lesotho Legend
In January 2018 Gem Diamonds announced the largest diamond yet discovered at Letšeng, a Type IIa D color stone measured at 910 carats.[10]. The same year a light brown diamond of 357.61 carats was discovered.
Letšeng Star
In august 2011 a diamond of 550 carats was found.
Letšeng Dynasty and Letseng Destiny
In May and July of 2015, the discovery of two large diamonds was announced : the Letšeng Destiny of 314 carats and the Letšeng dynasty of 357 carats.[11].
See also
References
- ^ 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". 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.
- ^ "Archived copy". Archived from the original on 15 January 2018. Retrieved 15 January 2018.
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: CS1 maint: archived copy as title (link) - ^ [1]