Emerald is the green variety of Beryl, and its most precious and valuable variety. Its intense green color has given it status as an important gemstone throughout the centuries. The color of Emerald is green to emerald-green. The light green form of Beryl is not recognized as Emerald, but rather Green Beryl. The deep color of Emerald is caused by traces of the element chromium, but sometimes also vanadium.
The ancient source of Emeralds in the old world was Egypt, but their quality was not exceptional. However, the Native South American civilizations such as the Incas have had high quality Emeralds from the mines of Colombia, which have traditionally produced the highest quality Emeralds and continue doing so.
Emeralds can be transparent and gemmy, in which case they are extremely valuable, or they can be in opaque or semi-opaque forms which are much more common and not as valuable.
They are sometimes heat treated, which causes their color to turn blue and transform into Aquamarine.
Emeralds are notorious for their flaws. Flawless stones are very uncommon, and are noted for their great value. Some actually prefer Emeralds with minute flaws over flawless Emeralds, as this proves authenticity. Flaws are often hidden by treating the Emeralds with oil or synthetic lubricants, and this is a common practice in the industry.
Though Colombian Emeralds have traditionally been the highest quality Emeralds with the finest green color, a new source of Emerald from the African country of Zambia has been producing deep green Emeralds with fewer flaws.
Though Emerald has good hardness, it is a brittle stone. It may develop internal cracks if banged hard or if subject to extreme temperature change. Emeralds that were treated to mask internal flaws should never be cleaned with an ultrasonic jewelry cleaner, nor should they be washed with soap. These practices may remove the oiling treatment and expose the hidden internal flaws.
USES
Transparent emeralds are faceted into gem cuts for jewelry, and make one of the most popular jewelry gemstones. Emerald is very sensitive to pressure and banging, and the well-known emerald cut was developed specifically for this gem to reduce the amount of pressure during cutting. Translucent Emeralds are cut and polished into cabochons and beads, as are Trapiche Emeralds.
Emerald is the birthstone of May.
VARIETIES
Brazilian Emerald - Emerald from Brazil. The term Brazilian Emerald may also refer to green Tourmaline from Brazil.
Cat’s Eye Emerald - Emerald exhibiting cat’s eye effect. Cat’s eye emerald is very rare, and only exists on paler Emeralds.
Colombian Emerald - Emerald from Colombia. This Emerald is usually regarded as the highest quality.
Star Emerald - Synonym of Trapiche Emerald.
Trapiche Emerald - Emerald with black impurities in the form of a six-rayed star.
Zambian Emerald - Emerald from the African country of Zambia. Zambian Emeralds can have very good color and transparency.
FALSE NAMES
Emeralds have been synthetically produced since 1848. Synthetic Emeralds currently produced can be very similar to true, natural Emeralds to the point that they may be virtually indistinguishable by normal means. Here are some names for synthetic emerald to watch out for:
Biron Emerald
Chathan Emerald
Gilson Emerald
Kimberly Emerald
Lennix Emerald
Linde Emerald
Regency Emerald
Zerfass Emerald
Glass dyed green is also a major Emerald simulator. The color of green glass and emerald may be identical, but other physical and optical properties can easily differentiate the two. Some fraudulent names given to green glass used as jewelry:
Broghton Emerald
Endura Emerald
Ferrer’s Emerald
Medina Emerald
Mount St. Helen’s Emerald
Spanish Emerald
Emerald in different cultures, and emerald lore
The Gachala Emerald is one of the largest gem emeralds in the world, at 858 carats (172 g). This stone was found in 1967 at La Vega de San Juan mine in Gachalá, Colombia. It is housed at the National Museum of Natural History of the Smithsonian Institution in Washington, D.C.
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