For nearly four centuries, Colombia was the world's largest exporter of emeralds. Today outperformed by Brazil, Colombian emeralds remain the most beautiful and renowned for their quality and clarity. It's a real national pride. Symbol of fertility and good health, these are precious stones prized for nearly four thousand years. Some stones may even cost more than diamonds. Colombians created emeralds of different varities, having different colors and qualities.

History of Emeralds:

The colors of the emeralds vary from a yellow-green to a deep blue-green. These are the darkest stones that we call "emeralds", the others are green beryls. For millennia, emeralds are considered sacred. In ancient Egypt, Cleopatra equated them with magic. In Latin America, the Incas and Aztecs dug in the earth to extract these divine stones from 500 BC. The Colombian territories filled with emeralds and gold are at the origin of the famous legend of El Dorado. These stories of treasures by thousands animated many Europeans who then began to conquer the El Dorado, it was the beginning of colonization and conquistadors. The Spaniards have loaded the emerald boats to Europe to exchange them for gold in Egypt, India and Persia.

Colombian Mines:

Colombia has 150 emerald deposits, the main ones being Muzo, Coscuez and Pita. They form the belt of emeralds in the Eastern Cordillera of the Andes and its high steep mountains covered with a dense jungle, in the regions of Cundinamarca (Bogota) and Boyaca (Villa de Leyva / Tunja). Emeralds are mined in narrow tunnel or open pit mines.

Mineralogical characteristics of the emerald:

A mineral from the group of silicates, subgroup of cyclosilicates, emerald is the most prestigious member of the family of beryl. Its famous green color, very stable in light, varies from pale green to deep green. It is most often due to chromium which enters into its composition or sometimes to vanadium (these are the rare vanadiferous emeralds).

Its hardness is 7.5 / 8 on a scale of 10. Transparent to translucent, the emerald often has inclusions of crystals, sometimes carbon that draws a star pattern (asterism). Liquid or gas may disturb it more or less. The emergence of emeralds results from the action of magmatic or hydrothermal veins on metamorphic rocks (transformed as a result of pressure or elevation of temperature). They are found under various appearances in quartz, micaschists, and pegmatites. Emeralds are frequently associated in deposits with albites, apatites, aragonites, barytes, calcites, dolomites, fluorites and pyrites.

The emerald remains one of four stones designated "precious" with diamond, ruby and sapphire, even though this name no longer officially exists since 2002. It is usually cut into a canted rectangle, this traditional form facets will take the name of "emerald cut".

Difference between natural sapphires and laboratory created: Sapphires are created naturally and also created in labs. The main difference between a natural and a laboratory sapphire created is its origin.  Laboratory created sapphire has the same physical properties, visual characteristics and level of hardness as natural stones. Natural sapphires are created by the earth and exploited, which makes them rare. The created lab stones are created by humans in a carefully controlled and common environment.

Article Source : http://buygemstonesonline.strikingly.com/blog/properties-and-virtues-of-the-emerald