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Letseng Diamond Mine
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 /hundred tons) and is known for producing huge diamonds, having the highest percentage of large diamonds (greater than ), 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. 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 an alpine tundra climate (''ET'', according to the Köppen climate classification). This means that Letšeng has a chilly climate with fairly cool temperatures throughout the year, even for Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout its life cycle, starting when, under suitable conditions, the ice crystals form in the atmosphere, increase to millimeter size, precipitate and accumulate on surfaces, then metamorphose in place, and ultimately melt, slide or sublimate away. Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets, which freeze in hexagonal-shaped crystals. Snowflakes take on a variety of shapes, basic among these are platelets, needles, columns and rime. As snow accumulates into a snowpack, it may blow into drifts. Over time, accumulated snow metamorphoses, by sintering, sublimation and freeze-thaw. Where the climate is co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Diamonds
Diamond (gemstone), Diamonds become famous typically for some combination of their size, color and quality. Diamonds occur naturally in many different colors, so the largest diamond of a particular color may not be large in absolute terms, but it may still be considered very desirable. Diamonds may also have high valuations or sale prices, or go on to have a noteworthy ownership history, but this will tend to occur for diamonds that had some outstanding characteristic to begin with. As new diamonds are discovered, the uniqueness of existing ones may diminish and there is no agreed-upon measure of a large or a high-quality diamond, so a strict inclusion criteria for notable diamonds is not attainable. Diamond A diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At Standard conditions for temperature and pressure, room temperature and pressure, another solid form of carbon known as graphite is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Rough Diamonds
This is a partial list of the largest non-synthetic diamonds with a rough stone (uncut) weight of over 200 carats (40 grams). The list is not intended to be complete – e.g., the Cullinan (formerly Premier) mine alone has produced 135 diamonds larger than 200 carats since mining commenced. De Beers generally does not publish information relating to large diamond discoveries. See also *List of diamonds * List of emeralds by size *List of individual gemstones *List of gold nuggets by size * List of sapphires by size References External links * {{List of precious stones by size * Largest rough diamonds diamonds Diamonds Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, bu ... Diamonds, rough ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining Industry Of Lesotho
The mining industry of Lesotho is mostly concentrated on diamond mining and as such the mining sector in the country has not played any significant role in furthering its economy. Apart from diamonds, the country's main mineral resources have been identified as base metals, clays, dimension stone, sand, gravel and uranium. The lack of initiative to extract other minerals commercially is mainly attributed to the inadequacy of infrastructure and finances. Between 2000 and 2011, the percentage of GDP contributed by diamond mining to Lesothos economy rose from "virtually zero" to about 4%. History The mining of diamonds started in the country only in the later part of the 1950s. Mining licenses for diamonds from Kao and Liqhobong pipes were operated for a short period from 1959 till Lesotho's independence. Following the independence of the country, the mines were closed due to poor production. In Lesotho's mining history, skilled artisans (known as Basotho diggers) have been extracting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colour For Diamonds
A chemically pure and structurally perfect diamond (gemstone), diamond is perfectly transparent with no hue, or ''color''. However, in reality almost no gem-sized natural diamonds are absolutely perfect. The color of a diamond may be affected by colors of chemicals, chemical impurities and/or structural defects in the Crystal structure#Lattice systems, crystal lattice. Depending on the hue and intensity of a diamond's coloration, a diamond's color can either detract from or enhance its value. For example, most white diamonds are discounted in price when more yellow hue is detectable, while intense pink diamonds or blue diamonds (such as the Hope Diamond) can be dramatically more valuable. Of all colored diamonds, red diamonds are the rarest. The Aurora Pyramid of Hope displays a spectacular array of naturally colored diamonds, including red diamonds. History of color grading Color grading of diamonds was performed as a step of sorting rough diamonds for sale by the London Diamond S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black South Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Köppen Climate Classification
The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notably in 1918 and 1936. Later, the climatologist Rudolf Geiger (1894–1981) introduced some changes to the classification system, which is thus sometimes called the Köppen–Geiger climate classification system. The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (temperate), ''D'' (continental), and ''E'' (polar). Each group and subgroup is represented by a letter. All climates are assigned a main group (the first letter). All climates except for those in the ''E'' group are assigned a seasonal precipitation subgroup (the second letter). For example, ''Af'' indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lesotho
Lesotho ( ), officially the Kingdom of Lesotho, is a country landlocked country, landlocked as an Enclave and exclave, enclave in South Africa. It is situated in the Maloti Mountains and contains the Thabana Ntlenyana, highest mountains in Southern Africa. It has an area of over and has a population of about million. It was previously the British Crown colony of Basutoland, which declared independence from the United Kingdom on 4 October 1966. It is a fully sovereign state and is a member of the United Nations, the Commonwealth of Nations, the African Union, and the Southern African Development Community. The name ''Lesotho'' roughly translates to "land of the Sotho". History Basutoland Basutoland emerged as a single body politic, polity under King Moshoeshoe I in 1822. Moshoeshoe, a son of Mokhachane, a minor tribal chief, chief of the Bakoteli lineage, formed his own clan and became a chief around 1804. Between 1820 and 1823, he and his followers settled at the Buth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra Climate
The tundra climate is a polar climate sub-type located in high latitudes and high mountains. undra climate https://www.britannica.com/science/tundra-climateThe Editors of Encyclopaedia Britannica, 2019 It is classified as ET according to Köppen climate classification. It is a climate which at least one month has an average temperature high enough to melt snow (), but no month with an average temperature in excess of . Despite the potential diversity of climates in the ''ET'' category involving precipitation, extreme temperatures, and relative wet and dry seasons, this category is rarely subdivided. Rainfall and snowfall are generally slight due to the low vapor pressure of water in the chilly atmosphere, but as a rule potential evapotranspiration is extremely low, allowing soggy terrain of swamps and bogs even in places that get precipitation typical of deserts of lower and middle latitudes. The amount of native tundra biomass depends more on the local temperature than the amoun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Dollar
The United States dollar ( symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official currency of the United States and several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar, divided it into 100 cents, and authorized the minting of coins denominated in dollars and cents. U.S. banknotes are issued in the form of Federal Reserve Notes, popularly called greenbacks due to their predominantly green color. The monetary policy of the United States is conducted by the Federal Reserve System, which acts as the nation's central bank. The U.S. dollar was originally defined under a bimetallic standard of (0.7735 troy ounces) fine silver or, from 1837, fine gold, or $20.67 per troy ounce. The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
