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Diamond Mines
Diamond mines are found all over the world. Many mines are rivers, such as, the Rio Abaete in Minas Gerais, Brazil, or other seabeds such as, the Namibian coast in Namibia and the rivers from Angola to South Africa. The land mines where most gems are found are in every continent except Europe and Antarctica, with the largest mine in the world called the Argyle Mines located in Western Australia. The seabeds, such as the rivers and oceans are called alluvials. Diamonds are found on land in a rare type of volcano rock called kimberlite, named, after the Kimberley area in South Africa, and they are also found in a rare volcano rock called the lamproite. On land, gems found deep inside of volcano rocks are rapidly carried to the surface of the earth during violent volcano eruptions.
Diamonds are carried to the surface in magma or molten rock. If these gems cool too slowly on their way up, they can turn to graphite, any contact with oxygen can cause these gemstones to become puffs of carbon dioxide gas. So, these gems are at risk when they are carried to the Earth's surface. They survive the journey to the Earth's surface and they are usually found in a rock contained in a narrow, carrot-shaped 'pipe' or in a thin fissure. Some gems are washed downstream and accumulate in river beds, ocean floors or on shorelines. When miners find them, they are still in their rough (unpolished state of gemstones). Once the miners find these gems, the process of getting them sold begins. Many gems are sold to DeBeers, a diamond firm located in South Africa. DeBeers then determine the price of the rough gems and sell them to approximately 80 "sightholders" (major cutting firms) which are the only companies authorized to buy rough gems directly from DeBeers.
DeBeers and the World Diamond Council (a newly formed international body recognized by the United Nations) have created a system of international certification and controls from the diamond mines to the cutting centres around the world to guarantee that all gems purchased from DeBeers are conflict free. The Diamond Mines are dangerous work sites. They are capital intensive, long-term projects, and it is essential that all decisions regarding investments in the operations are made in line with the long-term interests of all stakeholders and of the mining countries. Workers are sent out the find the kimberlite pipes, which are large areas of volcano rocks, in search of diamonds. The workers live at a secure site for six months at a time near the kimberlite pipes, leaving the site after completing their security search. Diamond production begins as soon as the gems are found at the mines, sold to the popular firms such as DeBeers. Then the gems are sent to the diamond cutting centres around the world. The Diamond Centres cut the gems out of their roughs to be polished and priced. Prices are set according to the size, clarity, carat, color, and cut of the gemstones using the grading system. From Diamond Mines to Grading System From Diamond Mines To Home Page
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