Emerald: Difference between revisions

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''For other things of this name, see [[Emerald (disambiguation)]].''

[[Image:Cut_EmeraldsEmerald.jpg|rightpng|thumb|ThreeEmerald showing its cuthexagonal emeraldsstructure]]

[[Image:Emerald.png|right|thumb|Emerald showing its hexagonal structure]]

[[Image:emerald_rough_300x422.jpg|right|thumb|Emerald with inclusions]]

'''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 mineral hardness|Mohs scale]] of hardness. Emerald is the [[birthstone]] for [[May]] as well as the traditional [[gift]] for the 55th [[wedding anniversary]].

==Synthetic emerald==

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 [[Fluorescence|fluoresce]] a dull red with long wave [[UV]] whereas most natural specimens do not. Also both the [[densityspecific gravity|densitiesspecific gravities]] (natural: 2.70 - 2.78, synthetic: 2.66) and [[refractive index|refractive indices]] (natural: 1.576 - 1.582, synthetic: 1.565) of synthetics are slightly lower. Wispy inclusions are common in flux-grown synthetic emeralds.

==Culture and folklore==

Emerald is regared as the [[birthstone]] for May. In some cultures the emerald is the traditional gift for the 55th wedding anniversary.

==See also==

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 [[density|densities]] and [[refractive index|refractive indices]] of synthetics are slightly lower. Wispy inclusions are common in flux-grown synthetic emeralds.

See also:* [[List of minerals]]

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

*Weinstein, Michael, 1958, ''The World of Jewel Stones'', Sheriden House

*Diamond Bug. [http://diamondbug.blogspot.com/2005/05/birthstone-for-may-emerald.html "Birthstone for May: Emerald"]. Retrieved May 13, 2005.

[[Category:Gemstones]]