Emerald

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

Emerald 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.

Emerald is a rare and valuable gemstone which naturally 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.

Emerald in the rough

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

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