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The process of enhancing a gemstone to bring out its beauty is a generally accepted practice and is defined as any treatment other than cutting or polishing that improves its appearance, durability or availability. Gemstones can be divided into 3 basic categories: "N" for natural stones that have been not enhanced "E" for stones that have been normally enhanced but since many enhancement methods are difficult or impractical to prove, the approach taken is to assume that such enhancement has been applied to that particular gemstone. If a specific method of enhancement is known, then that specific enhancement code will be used. For gemstones that are not covered by the "N" or "E" symbols, the specific code for the gemstone enhancement will be used. A - Not Normally Enhanced; Typically not enhanced, enhancements (if any) are unknown. B - Bleaching: The use of chemicals or other agents to lighten or remove a gemstone's color. C - 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. D - Dyeing : The introduction of coloring matter into a gemstone to give it new color, intensify present color or improve color uniformity. F - Filling: As a by-product of heat enhancement, the presence of solidified borax or similar colorless substances which are visible under properly illuminated 10X magnification. G - Gamma/Electron Irradiation: The use of gamma and/or electron bombardment to alter a gemstone's color; may be followed by a heating process. H - Heating: The use of heat to effect desired alteration of color, clarity, and/or phenomena. (Residue of foreign substances is not visible under properly illuminated 10X magnification.) I - Infilling: The intentional filling of surface breaking cavities or fractures usually with glass, plastic, opticon with hardeners and/or other hardened foreign substances to improve durability, appearance and/or add weight. L - Lasering: The use of a laser and chemicals to reach and alter inclusions in diamonds. O - Oiling/Resin Infusion: The intentional filling of surface cavities of a colorless oil, wax, natural resin, or unhardened man-made material into fissured transparent/translucent gemstones to improve appearance. (i.e., oil, man-made resin, cedar wood oil, Canada balsam, paraffin, etc.) R - Irradiation: The use of neutron, requiring an environmental safety release from the Nuclear Regulatory Commision (NRC), with the combination of any other bombardment and/or heat treatment to alter a gemstone's color. S - Bonding: The use of a colorless bonding agent (commonly plastic) within a porous gemstone to give it durability and improve appearance. U - Diffusion: The use of chemicals in conjunction with high temperatures to produce color and/or asterism-producing inclusions. W - Waxing/Oiling: The impregnation of a colorless wax, paraffin and oil in porous opaque gemstones to improve appearance. |
