Emerald
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For other things of this name, see Emerald (disambiguation).
Emerald (Be3Al2SiO6) is a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes iron. It is highly prized as a gemstone and by weight is the most valuable gemstone in the world, often made more so by inclusions. Beryl has a hardness of 8 on the 10 point Mohs scale of hardness. Emerald is the birthstone for May as well as the traditional gift for the 55th wedding anniversary.
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Emerald is a rare and valuable gemstone and, as such, provided the incentive for developing synthetic emeralds. Both hydrothermal and flux-growth synthetics have been produced and a method has been developed for producing an emerald overgrowth on colorless beryl. Synthetic emeralds fluoresce a dull red with long wave UV whereas most natural specimens do not. Also both the densities and refractive indices of synthetics are slightly lower. Wispy inclusions are common in flux-grown synthetic emeralds.
See also: List of minerals
References
- Sinkankas, John, 1994, Emerald & Other Beryls, Geoscience Press, ISBN 0801971144
- Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., John Wiley and Sons, New York ISBN 0471805807
- Diamond Bug. "Birthstone for May: Emerald" (http://diamondbug.blogspot.com/2005/05/birthstone-for-may-emerald.html). Retrieved May 13, 2005.bg:Изумруд
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