Gem Resources International

Gemstone Treatment

Many dealers treat their gemstone materials through several methods, in order to gain higher prices when released onto the world gem markets. Some treatment methods are still used, whereas others have been ceased due to the tendency to lower the value of the material. It is important to know whether or not the stone you are purchasing has been treated in some way, and which treatment method was used.

We wish to educate our customers in the accepted methods of gem treatments found within our materials, as well as those found throughout the gem industry.

The goal of any gem treatment is to improve the stone�s color and clarity. Some methods help to remove inclusions; some fill the cracks in a stone; other methods can make clear crystals appear colorful.

The following is a list to help you identify and understand some of the gemstone treatments known to exist in the gem trade. Some treatments are temporary while others are permanent.

 

None : Indicates this particular gemstone has received absolutely no enhancements.

Heating : The use of heat to achieve a desired alteration of color, clarity,and /or phenomena. This is a permanent treatment. Examples: Aquamarine, Quartz.

Diffusion: The use of chemicals in conjunction with high temperatures to produce color and/or asterism-producing inclusions. This is a permanent treatment. Examples: Topaz, Sapphire.

Irradiation : The use of neutron bombardment to alter a gemstone's color; may be followed by a heating process. This is a permanent treatment. Examples: Topaz, Diamonds.

Coating : The use of surface enhancements such as lacquering, enameling, inking, foiling, or sputtering of films to improve appearance, provide color or add other special effects. This is a temporary enhancement.Examples: Emerald, Opal.

Dyeing : The introduction of coloring matter into a gemstone to give it new color, intensify present color or improve color uniformity. This is a temporary enhancement. Examples: Quartz varieties.

Oiling/Resin Infusion: The intentional filling of surface breaking cavities with a colorless oil, wax, natural resin, or unhardened man-made material into fissured transparent gemstones to improve appearance. (i.e., oil, man-made resin, cedar wood oil, Canada balsam, paraffin, etc.) This is a temporary enhancement. Examples: Emerald.

Filling : As a by-product of heat enhancement, the presence of solidified borax or similar colorless substances. This is a temporary enhancement. Examples: Emerald, Opal.

Infilling : The intentional filling of surface cracks or fractures usually with glass, plastic, or other hardened foreign substances to improve durability, appearance and / or weight. This is a temporary enhancement. Example: Emerald, Mexican Opal.

Waxing/Oiling: The impregnation of a colorless wax, paraffin and oil in porous opaque gemstones to improve appearance. This is a temporary enhancement. Examples: Emerald, Opal.

Laser : The use of a laser and chemicals to reach and alter inclusions in diamonds. This is a permanent treatment.