Emerald Treatments & Disclosures
Unless stated otherwise, all the emeralds we sell can assume to have been treated with a standard industry treatment known as oiling. Emeralds International has been disclosing emerald treatments since the early 1960’s, long before the industry began to develop and implement treatment disclosures, particularly for emerald. From the moment a gem is removed from the earth the enhancement and treatment process begins.
Although there is nothing wrong with gemstone treatment and enhancement, it is important to disclose them. There are many types of unethical or unknown treatments being applied to gems that are not being disclosed to dealers and re-sellers which can be problematic for the consumer and the industry.
There are many opinions on treatments, therefore what we state here is our own expert opinion based upon our 62 years of experience with this gem and with that of other source opinions that we may agree with. Of all the precious stones, the emerald is actually among the lesser enhanced. It cannot successfully be laser treated, heat treated, irradiated, or diffusion treated. Its most common method of enhancement is one practiced since the days of Cleopatra: the introduction of an oil or now, in modern times, a polymer resin impregnated into the body of the emerald through surface reaching fissures. Emeralds International, LLC, was the first jewelry retail store to disclose the clarity enhancement process of emeralds as early as 1964 and is a strong proponent for all enhancement disclosures in gemstones. As a young emerald miner and dealer, Manuel Marcial de Gomar used to receive rifle cases of rough emeralds from other miners soaked in rancid pigs fat for sale in the markets in Bogota – not something a consumer would want to smell today. Although the type of material used in treatments has expanded and improved, the amount of enhancement material in emeralds is usually very minute as it is limited to avenues of entrance such as micro fissures on the surface of the stone, which sometimes appear during the process of cutting and polishing the emerald. The oil, or polymer, has the same or close refractive index as the emerald, allowing light to pass through thus making the micro fissures largely invisible to the naked eye and allowing color to project through the gem even better. Although these oils can slowly come out over time or via long periods in an ultrasonic, they can most often be re-treated if no hardening agents have been used. Any oiling treatment done by Emeralds International does not contain hardening catalysts. The patented Excel process by Arthur Groom & Co., a modern treatment, is the most permanent treatment to date and can also be reversed. Opinions on which treatments are better will vary from time to time depending on the market and who’s trying to sway opinion. At one time it was resins and now cedar oil is being pushed. Some prefer cedar oil and some prefer the Excel process etc. In our opinion we have seen and used them all and at the end of the day consider them all to be acceptable (with varying pros and cons) as long as they are accepted within industry standards and disclosed. Remember, although clarity enhancement can improve the appearance of a gem they cannot make a heavily included emerald appear to have very slight inclusions and there is little to no improvement in the appearance of emeralds that have very few or no surface-reaching fissures. Composite emeralds or rubies and sapphires are a completely different creature and do not fall under the acceptable standard treatment category of emeralds. Ever realized how oily human skin is? Just picking up an emerald with ones fingers will leave oil residues on the surface.
Adding green coloring agents to emeralds is viewed by Marcial de Gomar’s Emeralds International, LLC, as somewhat unethical, although it may be legal in many countries, and should be clearly disclosed verbally beforehand, and in writing at point of sale.
As a member of the American Gem Trade Association (AGTA) we are happy to share valuable information on gem treatments and are committed to providing disclosures on any gem we sell.
You can view their PDF booklet on treatments here.