Emerald

Emerald (Be₃Al₂SiO₆) is a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes iron. more...

It is highly prized as a gemstone and by weight is the most valuable gemstone in the world, often made more so by inclusions, which all emeralds have. Beryl has a hardness of 8 on the 10 point Mohs scale of hardness. Many countries import emeralds, Colombia being the first exporter of emeralds in the world.

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 fluoresce a dull red with long wave UV light due to an indicator added during the process of synthesizing the emerald, whereas natural specimens do not. Also both the specific gravities (natural: 2.70 - 2.78, synthetic: 2.66) and 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 historical/mythical usage

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

According to Rebbenu Bachya, the word "Nofech" in the verse Exodus 28:18 means "Emerald" and was the stone on the Ephod representing the tribe of Judah.

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