The treatment and enhancement of gemstones has existed for thousands of years. Many of these treatments are still being used today !
Some enhancements improve on nature, which are permanent; this provides the gem market with a larger supply of beautiful gemstones. Other treatments produce dramatic changes in the gemstone itself or it’s clarity; the irradiation and heating of colorless topaz that permanently transforms it into blue topaz is an excellent example. Following is a description of some common treatments.
Bleaching: The use of heat, light or chemicals to lighten or remove a gemstone’s color.
Coating: The use of such surface enhancements as lacquering, enameling, inking, foiling, or sputtering of films to improve appearance, provide color or add other special effects.
Dyeing: The introduction of coloring matter into a gemstone to give it new color, intensify existing color or improve color uniformity.
Filling: The filling of surface - breaking cavities or fissures with colorless glass, plastic, or some similar substance. This process will improve durability, appearance and / or add weight. Example: ruby.
Heating: The use of heat to alter color, clarity, and / or phenomena. Example: tanzanite.
Impregnation: The impregnation of a porous gemstone with a colorless agentia (usually plastic) to give it durability and improve appearance.
Lasering: The use of a laser and chemicals to reach and alter inclusions. Example: diamond.
Oiling / resin infusion: The filing of surface - breaking fissures with a colorless oil, wax, resin or other colorless substances, except glass or plastic, to improve the gemstone ’ s appearance. Example: emerald.
Irradiation: The use of neutrons, gamma ray , ultraviolet and / or electron bombardment to alter a gemstone’s color. The irradiation may be followed by a heating process. Example: blue topaz.
Waxing / Oiling: The impregnation of a colorless wax, paraffin and / or oil in porous gem - stones to improve appearance. Example: jadeite.