Emerald - "Nothing greens greener..."

(Pliny the Elder, ca. 50 A.D.)

May's birthstone, the emerald has always been one of the most revered and expensive of gemstones. The name emerald is derived from the Latin 'smaragdus', meaning 'green'. Its normal color is a beautiful hue known, not surprisingly, as 'emerald green.' But emeralds come in a variety of shades, from light green, leaf green, bright green to dark green.

Beryl Gemstone Family

The emerald, a crystal structure composed of beryllium and aluminum, belongs to the beryl family of gemstones. Other members of the beryl family are aquamarine (blue, blue-green), goshenite (white), morganite (peach, pink) and helidor (yellow, gold). The emerald's vivid green hue is a consequence of chromium replacing aluminum in the structure of beryl. (Note: there are other green beryls which are not emerald because they contain no chromium.)

Emerald Hardness

Emerald ranks 7.5 - 8 on the Mohs scale of hardness. Although it is a fairly hard stone (more so than quartz but not as hard as ruby or sapphire), emerald can also be brittle. This is principally due to inclusions built in to the structure, and emeralds can split along the inclusions if they receive a sharp knock.

Where are Emeralds Mined?

Nowadays, most natural gem-quality emeralds are the produce of Brazil, Zambia and Columbia. They are also produced in Tanzania, Zimbabwe, South Africa, Madagascar, Australia, Russia and the United States (North Carolina). The history of the emerald goes back several thousands of years to ancient Egypt, where Cleopatra was renowned for wearing them. Columbia enjoys the reputation of producing the best emeralds, but Brazil is fast closing the gap in terms of quality.

Laboratory Emeralds

There is a recent trend to grow emeralds in the laboratory, and these stones are beginning to appear on the market. Laboratory emeralds are identical to natural ones in terms of color, brilliance, hardness and inclusions. A trained gemologist can tell the difference. The consumer cannot - and this is causing a certain amount of controversy in the industry.

Cleaning Emeralds

Emeralds should be cleaned with a soft, damp cloth and warm water, using a soft brush. Mechanical cleaners should be avoided. During the cutting and processing of emeralds, a gemologist may apply oils to conceal inclusions. Avoid applying heat or chemicals which may dissolve these oils. It is advisable to have a jeweler re-oil your emeralds from time to time. Avoid impact: although emeralds are quite hard, their crystal structure is prone to brittleness. If you purchase your emerald through a reputable dealer, he should provide written special care notes and information pertinent to the gem.

Next: History Of Emeralds