Guest Author - Susan Dorling

Fine emeralds are truly breathtaking gemstones. Long regarded as the pinnacle of green gemstones, and the yardstick against which all other green stones are compared, emeralds are one of the four most valuable gemstones in the world along with diamond, ruby, and sapphire. It is no wonder then that emeralds were a passion of Cleopatra and have been held in high esteem by royalty in all cultures throughout the ages.

The per carat price of fine quality emerald escalates rapidly with size. Although emeralds as gemstones are not rare—large specimens that exhibit slightly bluish green vibrant color with deep saturation are a rarity and highly valued. Clarity is also important, however, inclusions are more tolerated in emeralds than in any other gemstone.

Emeralds of fine quality can fetch more than a diamond of the same size, with premium quality emeralds costing thousands of dollars per carat. However, the market is brimful of a wide selection of emeralds of varying often dubious quality that range from as low as $10 per carat. Within this range, one can find emerald jewelry that is compatible with one’s budget, but be mindful of choosing carefully from reputable jewelry sources to guarantee you are getting what you pay for.

The center of world emerald mining is in South America with Colombia and Brazil as major producers. The continent of Africa is the second largest producer with mines in Zambia, Zimbabwe, Madagascar, and Nigeria. Each of these world locales typically produces emeralds of a certain color, size, and clarity that is recognized by emerald aficianados as being from that particular region.

Emerald, by definition, is a medium or darker green to bluish green beryl, in which the green color is derived from impurities of chromium or vanadium or a combination of both. Before 1963 the definition was limited to chromium containing stones, but the discovery of a large deposit of vanadium colored stones in Brazil led to modification. Varying amounts of iron will affect the color as well, with more atoms of this impurity increasing the bluish tones. In a situation similar to that which exists with the boundary between pink sapphire and ruby, there are chromium colored stones of light to medium light green color which are sometimes sold as emerald, but which are more correctly considered green beryl.

Emeralds are considered a "Type III" gemstone by GIA which means that they are virtually always included to one degree or another. Because of this designation, a clarity grade of "very slightly included" for example, refers to the normal range for emeralds, not for all gemstones. Well over 90% of the emeralds in commerce have been treated to minimize the appearance of the inclusions.

The industry practice for treatment (and that which is considered "standard" by AGTA) is "oiling". This term refers to the practice of immersing emeralds, rough and/or cut, in a colorless oil or resin of natural or man-made origin. Often this is done using a vacuum chamber to assist penetration. Non-standard treatments go beyond this to using green colored oils and hardened (epoxy-like) resins. These treatments dramatically improve the appearance of the gems, but necessitate special care in cleaning and setting. Steam cleaners, solvents and ultrasonics can remove the oils, making inclusions, which had barely been visible before cleaning, stand out in sharp relief. Luckily, it is possible to have emeralds re-oiled.

The inevitable inclusions are more than a strictly aesthetic consideration as they can reduce the structural integrity of the gem. Beryls, in general, are good jewelry stones, with a hardness of up to 8 and no troublesome cleavages. Emeralds, though, because of the inclusions are generally somewhat more fragile than other beryls and must be treated more gently.

Emerald Simulants
If you love emeralds but can’t find authentic emerald jewelry that falls within your budget restrictions, why not consider some of the beautiful emerald simulants and synthetics (lab-created) in the marketplace today. The Cubic Zirconia simulants are amazing—check out the emerald simulant jewelry at The Hollywood Collection. I guarantee you will be impressed and perhaps start your own gemstone collection.

Vibrant sparkling emerald green cubic zirconia is a favorite emerald imitation as is glass, beryl triplets, synthetic spinel triplets, and YAG. The synthetics are more costly than cz’s and other simulants because their creation requires expensive equipment, labor-intensive processes, and the production of cuttable gems is relatively low yield for the long time it takes to produce them. Interestingly, some of these synthetic emeralds make the job of appraisers and gemologists a little more difficult, due to their resemblance to real emeralds. However, in the majority of cases, there are clues—most often related to inclusions—which can conclusively verify natural versus synthetic origin.

Gemological Properties:
Chemical Composition: Beryllium Aluminun Silicate
Crystal System: Hexagonal
RI: 1.57 - 1.58
Density: 2.71
DR: .006
Pleochroism: Dichroic: blue green/yellow green
Dispersion: .014
Cleavage: unimportant
Luster: Vitreous
Hardness: 7.5 - 8
Toughness: Poor to Good

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