Gemstone Treatments

The history of gem treatments is as old as the gem trade itself.  One of the earliest references to gem treatments is found in Pliny's History of the World.  Pliny The Elder [23-79 AD].  Another early work mentioning gem treatments is that of an anonymous Egyptian whose writings have survived in the form of two papyri believed to date from the third or fourth centuries AD.  Still another ancient mention of Heat treatment of corundums has been found in a number of early works, particularly by Arabs (About 1240 AD).  Some treatments bring out the stone's inherent qualities.  Emeralds, for example, are routinely oiled to bring out their color.  Such treatments do not camouflage flaws or harm the stone in any way.

As an accepted industry standard, gemstones are heat-treated to improve the color and clarity and overall appearance.  Some sapphires are found closer to thermal venting in the earth, which produces exceptional color through natural heating.  By heating gemstones that are not found in these locations, mimicking of this natural process takes place.  No radiation, chemicals or health risks are involved in this process.  As is common with almost all gems available today, majority of Angara gemstones are heat-treated.

Understanding what you are purchasing is the first step in making an informed and secure decision.

Certain treatments bring out a stone's inherent qualities.  Emeralds, for example, are oiled to bring out their color.  Such treatments do not camouflage flaws or harm the stone in any way.  The FTC guidelines specify the requirement to mention treatments of a kind of gem.  There are other treatments that are done to stones of lower quality to make them appear more attractive.  As technology improves, the variety of enhancements proliferates.  An official of the American Gem Trade Association declared recently that enhancements are prevalent today because "the consumer has developed these unreal expectations of what they want in a gemstone."  If we see a gemstone in its untreated state, it has not even half the appeal that 'normal' gemstones in the industry have.

Brief explanations of various treatments in the industry are given below.

Oiling

Mostly emeralds are treated to derive an attractive green color and clarity.  Similarly, other colored stones such as rubies are treated in this way to reduce surface inclusions.  This treatment reduces fractures and also improves clarity.  Wax and natural or synthetic resins are used, besides colorless oil.  Oiling treatment is not permanent but generally an accepted treatment.

Heating

Heat treatment is the most common enhancement.  This is quite common with corundums, ruby and sapphire.  Heating of most kinds of gemstones is a standard treatment procedure.  Heating has been used for centuries.  Heating Methods vary from simply burning to greatly advanced techniques.

Heating does not change the atomic structure of the gems.  Heat Treatment is permanent and acceptable.  Heated gemstones are very easy to keep; they do not require any special care.

Diffusion

Diffusion is an enhancement method, commonly used with corundums.  The process lies in adding iron and titanium during the heating process of a gemstone.  Sometimes it is called surface diffusion.  In this, a layer is created on the surface.  This layer is described as colored coating. By re-cutting, polishing or scratching diffused gems may alter in appearance.

Irradiation

Irradiation means pounding a material with subatomic particles.  In some cases, irradiation is followed by heating to produce a better color of the gem.  Today, many irradiation techniques are applied.  Through this method, dark pink tourmaline can change into red.  For diamonds, irradiation and heating can result in browns, blues, yellows, pinks and greens.  Irradiated diamonds sell for much less price per carat than the naturally colored ones of comparable quality.  Irradiation treatment is believed to be permanent.