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Letseng Diamond Mine, Mokhotlong District, Lesothoi
| Regional Level Types | |
|---|---|
| Letseng Diamond Mine | Mine |
| Mokhotlong District | District |
| Lesotho | Country |
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Latitude & Longitude (WGS84):
29° 0' 0'' South , 28° 51' 49'' East
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Mokhotlong | 8,809 (2010) | 37.7km |
| Phuthaditjhaba | 84,258 (2012) | 53.1km |
Other/historical names associated with this locality:
Letseng-La-Terae Mine; Letseng Mine; Lets'eng Mine
A diamond mine, currently owned by African Gem Diamonds.
The deposit consists of several kimberlite pipes intruded through 1500 m of Karoo (Stormberg) basalt.
Two of the pipes, referred to as the Main and Satellite pipes respectively, have economic grades.
They were discovered in 1957 as a weathered outcrop in a stream.
In 1959, it was declared a "government digging" and hundreds of small-scale miners started to excavate the near-surface weathered kimberlite.
In 1968, the property was acquired by Rio Tinto and explored through a series of underground tunnels, but the prospect was abandoned in 1972.
De Beers subsequently acquired the deposit and mined the Main Pipe from 1975 until 1982. During this time, only little work was done on the Satellite Pipe.
In 1999, the mining rights were obtained by Letseng Diamonds, which focused their activities on the Satellite Pipe.
In 2007, the mine was acquired by African Gem Diamonds.
During mining operations in the Satellite Pipe, a high number of large diamonds of exceptional quality were recovered, among them stones of 72, 76, 106 and 112 carats within a single week. The 603 ct "Lesotho Promise", discovered in 2006, ranks as the world's 15th largest diamond. It is said that 15% of the production is larger than 10 carats, and 1% is larger than 100 carats, per stone.
The Letseng pipes also contain abundant mantle and lower crustal xenoliths, including garnet-bearing gneisses and granulites, eclogites, lherzolites, harzburgites, and dunites.
A 494-carat diamond, believed to be the 18th largest in the world, has been found at this mine in Lesotho.
The stone was an exceptional quality white diamond, said Natural Resources Minister Monyane Moleleki. "This recovery adds more to the chapter of excellence for this mine internationally," said a visibly elated Moleleki.
The Lesotho Promise, a 603-carat stone, was uncovered last year (2006) at the same mine and sold for $12.3 million. A 215-carat flawless diamond found in January 2007 brought $8.3 million.
The stone was an exceptional quality white diamond, said Natural Resources Minister Monyane Moleleki. "This recovery adds more to the chapter of excellence for this mine internationally," said a visibly elated Moleleki.
The Lesotho Promise, a 603-carat stone, was uncovered last year (2006) at the same mine and sold for $12.3 million. A 215-carat flawless diamond found in January 2007 brought $8.3 million.
A 910-carat diamond, the fifth largest ever discovered and as big as 2 golf balls, was found here as reported on January 15, 2018. It has been speculated that it may be worth as much as $40,000,000.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded from this region.Mineral List
Mineral list contains entries from the region specified including sub-localities12 valid minerals. 1 (TL) - type locality of valid minerals. 1 erroneous literature entry.
Detailed Mineral List:
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Taenite | 1.AE.10 | (Ni,Fe) |
| ⓘ | Cohenite | 1.BA.05 | Fe3C |
| ⓘ | Diamond | 1.CB.10a | C |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Crowningshieldite (TL) | 2.CC. | (Ni0.9Fe0.1)S |
| ⓘ | Pyrrhotite | 2.CC.10 | Fe1-xS |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Periclase | 4.AB.25 | MgO |
| ⓘ | var. Ferropericlase | 4.AB.25 | (Mg,Fe)O |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Calcite | 5.AB.05 | CaCO3 |
| Group 9 - Silicates | |||
| ⓘ | Majorite | 9.AD.25 | Mg3(MgSi)(SiO4)3 |
| ⓘ | Cebollite ? | 9.BB.10 | Ca5Al2(SiO4)3(OH)4 |
| ⓘ | Enstatite | 9.DA.05 | Mg2Si2O6 |
| ⓘ | var. Bronzite | 9.DA.05 | (Mg,Fe2+)2[SiO3]2 |
| ⓘ | Diopside | 9.DA.15 | CaMgSi2O6 |
| ⓘ | Pectolite | 9.DG.05 | NaCa2Si3O8(OH) |
| ⓘ | Natrolite | 9.GA.05 | Na2Al2Si3O10 · 2H2O |
| Unclassified | |||
| ⓘ | 'Apophyllite Group' | - | AB4[Si8O20]X · 8H2O |
| ⓘ | 'Fayalite-Forsterite Series' | - | |
| ⓘ | 'Plagioclase' | - | (Na,Ca)[(Si,Al)AlSi2]O8 |
| ⓘ | 'Garnet Group' | - | X3Z2(SiO4)3 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Apophyllite Group | AB4[Si8O20]X · 8H2O |
| H | ⓘ Cebollite | Ca5Al2(SiO4)3(OH)4 |
| H | ⓘ Natrolite | Na2Al2Si3O10 · 2H2O |
| H | ⓘ Pectolite | NaCa2Si3O8(OH) |
| C | Carbon | |
| C | ⓘ Calcite | CaCO3 |
| C | ⓘ Cohenite | Fe3C |
| C | ⓘ Diamond | C |
| O | Oxygen | |
| O | ⓘ Apophyllite Group | AB4[Si8O20]X · 8H2O |
| O | ⓘ Calcite | CaCO3 |
| O | ⓘ Cebollite | Ca5Al2(SiO4)3(OH)4 |
| O | ⓘ Diopside | CaMgSi2O6 |
| O | ⓘ Enstatite | Mg2Si2O6 |
| O | ⓘ Majorite | Mg3(MgSi)(SiO4)3 |
| O | ⓘ Natrolite | Na2Al2Si3O10 · 2H2O |
| O | ⓘ Pectolite | NaCa2Si3O8(OH) |
| O | ⓘ Periclase | MgO |
| O | ⓘ Enstatite var. Bronzite | (Mg,Fe2+)2[SiO3]2 |
| O | ⓘ Fayalite-Forsterite Series | |
| O | ⓘ Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
| O | ⓘ Garnet Group | X3Z2(SiO4)3 |
| O | ⓘ Periclase var. Ferropericlase | (Mg,Fe)O |
| Na | Sodium | |
| Na | ⓘ Natrolite | Na2Al2Si3O10 · 2H2O |
| Na | ⓘ Pectolite | NaCa2Si3O8(OH) |
| Na | ⓘ Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
| Mg | Magnesium | |
| Mg | ⓘ Diopside | CaMgSi2O6 |
| Mg | ⓘ Enstatite | Mg2Si2O6 |
| Mg | ⓘ Majorite | Mg3(MgSi)(SiO4)3 |
| Mg | ⓘ Periclase | MgO |
| Mg | ⓘ Enstatite var. Bronzite | (Mg,Fe2+)2[SiO3]2 |
| Mg | ⓘ Fayalite-Forsterite Series | |
| Mg | ⓘ Periclase var. Ferropericlase | (Mg,Fe)O |
| Al | Aluminium | |
| Al | ⓘ Cebollite | Ca5Al2(SiO4)3(OH)4 |
| Al | ⓘ Natrolite | Na2Al2Si3O10 · 2H2O |
| Al | ⓘ Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
| Si | Silicon | |
| Si | ⓘ Apophyllite Group | AB4[Si8O20]X · 8H2O |
| Si | ⓘ Cebollite | Ca5Al2(SiO4)3(OH)4 |
| Si | ⓘ Diopside | CaMgSi2O6 |
| Si | ⓘ Enstatite | Mg2Si2O6 |
| Si | ⓘ Majorite | Mg3(MgSi)(SiO4)3 |
| Si | ⓘ Natrolite | Na2Al2Si3O10 · 2H2O |
| Si | ⓘ Pectolite | NaCa2Si3O8(OH) |
| Si | ⓘ Enstatite var. Bronzite | (Mg,Fe2+)2[SiO3]2 |
| Si | ⓘ Fayalite-Forsterite Series | |
| Si | ⓘ Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
| Si | ⓘ Garnet Group | X3Z2(SiO4)3 |
| S | Sulfur | |
| S | ⓘ Pyrrhotite | Fe1-xS |
| S | ⓘ Crowningshieldite | (Ni0.9Fe0.1)S |
| Ca | Calcium | |
| Ca | ⓘ Calcite | CaCO3 |
| Ca | ⓘ Cebollite | Ca5Al2(SiO4)3(OH)4 |
| Ca | ⓘ Diopside | CaMgSi2O6 |
| Ca | ⓘ Pectolite | NaCa2Si3O8(OH) |
| Ca | ⓘ Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
| Fe | Iron | |
| Fe | ⓘ Cohenite | Fe3C |
| Fe | ⓘ Pyrrhotite | Fe1-xS |
| Fe | ⓘ Taenite | (Ni,Fe) |
| Fe | ⓘ Enstatite var. Bronzite | (Mg,Fe2+)2[SiO3]2 |
| Fe | ⓘ Fayalite-Forsterite Series | |
| Fe | ⓘ Periclase var. Ferropericlase | (Mg,Fe)O |
| Fe | ⓘ Crowningshieldite | (Ni0.9Fe0.1)S |
| Ni | Nickel | |
| Ni | ⓘ Taenite | (Ni,Fe) |
| Ni | ⓘ Crowningshieldite | (Ni0.9Fe0.1)S |
Other Databases
| Wikipedia: | https://en.wikipedia.org/wiki/Letseng_diamond_mine |
|---|---|
| Wikidata ID: | Q3642234 |
Localities in this Region
- Mokhotlong District
- Letseng Diamond Mine
Other Regions, Features and Areas containing this locality
AfricaContinent
African Plate
- Kalahari Craton
- Kaapvaal CratonCraton
- Karoo basinBasin
Somali PlateTectonic Plate
This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
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References
Field, Matthew; Stiefenhofer, Johann; Robey, Jock; Kurszlaukis, Stephan (2008) Kimberlite-hosted diamond deposits of southern Africa: A review. Ore Geology Reviews, 34 (1). doi:10.1016/j.oregeorev.2007.11.002
www.bloomberg.com (n.d.) https://www.bloomberg.com/news/articles/2018-01-15/one-of-the-biggest-diamonds-in-history-has-just-been-found
Smith, Evan M., Nestola, Fabrizio, Pasqualetto, Leonardo, Zorzi, Federico, Secco, Luciano, Wang, Wuyi (2021) The new mineral crowningshieldite: A high-temperature NiS polymorph found in a type IIa diamond from the Letseng mine, Lesotho. American Mineralogist, 106 (2). 301-308 doi:10.2138/am-2020-7567
Letseng Diamond Mine, Mokhotlong District, Lesotho