Selasa, 18 Disember 2012

Emeralds Around the World
Natural Colombian Emerald
Colombian Emerald

Colombia is most the most famous source for emeralds, but emeralds have been mined in many locations in the world. In fact recent decades have seen production increase from new deposits in south America and Africa.
The most famous deposit in Colombia is the Muzo mine northwest of Bogota. This deposit was first mined by Native Americans but was eventually abandoned and then rediscovered in the 17th century. The Muzo mine yields fine quality emerald of a deep green color. Another important deposit is the Chivor Mine, northeast of Bogota. More recently new deposits have been discovered which look promising for the future. Still, only a third of the emeralds mined in Colombia are worth cutting.
Brazil has emerald deposits in Bahia, Goias and Minas Gerais. The color of the Brazilian stones is lighter than the Colombian material; they tend to a yellow-green. But the Brazilian emerald is often relatively free of inclusions. New deposits have been found since 1980 and Brazil is now one of the most important suppliers of emeralds in the world.
Natural Brazilian Emerald
Brazilian Emerald
In the last several decades, increasing quantities of emeralds have been found in a series of small deposits in East Africa, particularly in Zimbabwe, Zambia and Tanzania. The East African emeralds are quite strong in color, sometimes with the desirable blue-green hue. The most famous of these emeralds are the ones from Sandawana in the south of Zimbabwe. The Sandawana crystals tend to be small but are very high quality.
Emeralds also are mined in South Africa, in the northern Trasvaal. Modern mechanized mining is carried out at the Cobra and Somerset mines, but only about 5% of the product is of good quality. Most stones are light in color or heavily included and only suitable for cabochons.
Other noteworthy emerald deposits are in India and Pakistan as well as in the Ural Mountains in Russia. Less important deposits have been found in Afghanistan, Australia, Ghana, Madagascar, Malawi, Mozambique, Namibia and the United States (North Carolina). In Europe, emeralds have been found in Austria and Norway.
The most famous emerald mines of antiquity were in Egypt. Known as the Cleopatra Mines or Mons Smaragdus (Emerald Mountains),they were worked as early as 2000 B.C. The mines were also worked during later centuries but they were abandoned after the Spaniards discovered emeralds in Colombia in 1545.

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