Gemstone enhancement has a long tradition and is a widely accepted practice in the jewelry industry. While some stones do not need any enhancement or treatments to look their best many others sold today require some form of conditioning or alteration to make the stone 'market ready.'
Customarily enhancements enrich the appearance of the gemstone. These techniques can improve the color clarity and durability of the gemstone. Enhancement processes vary based on the stone's characteristics and the necessary treatments required for bringing out the beauty of each stone. This list of common enhancements can help you identify what enhancement your gemstone jewelry may have undergone and how to best care for your purchase to keep it looking its best for years to come.
To improve durability or appearance. Assembled gemstones consist of two or more parts where at least one of these is a natural gemstone like in a doublet or triplet construction. The colored stone is sandwiched between a dark glass or semi-precious stone base and a protective natural crystal cap. This new three-layered stone is more resistant to impact and scratching than the original material.
To lighten or remove color. Heat light and/or other chemical agents are applied to the original material. This is especially common with pearl jewelry to remove discoloration on the surface of the pearl.
To improve appearance add color or other special effects. Surface enhancements like lacquering enameling inking foiling or sputtering of films are common in jewelry design. Modern gem coatings are indistinguishable from the gemstone like the coatings that are applied to eyeglass lenses. A prime example of a coated gemstone is the popular mystic topaz. An iridescent coating gives these stunners their signature rainbow radiance.
To change color and/or introduce asterism-producing inclusions. Diffusion enhancements are often undetectable on a microscopic level. Chemical elements in conjunction with high temperatures are introduced to the molecular structure of a gemstone. For example in natural gemstones the element chromium is typically responsible for a stone's green hue. By diffusing chromium to a neutral base material you can transform it into a green gemstone.
To enhance or change color. One of the oldest gemstone enhancements dyeing introduces pigment into a gemstone to give it new color intensify its original color or improve color uniformity. Chalcedony quartz and agate are commonly dyed to produce a popular variety of colors. While these dyes are stable you should take extra care to avoid prolonged exposure to moist heat.
Fissure Filling: FF
To improve durability or appearance or to add weight. Like getting a filling at the dentist gemstone fissure filling introduces material to fill surface-breaking cavities or fissures within a gemstone. Fillers may consist of colorless glass plastic solidified borax or similar substances. These substances are typically fused with the original gemstone material through a heating process.
To alter color or improve clarity. One of the most common gemstone enhancements heat treatment is slowly applied to gemstones at temperatures ranging from 200 to 2 000 degrees Celsius. Gemstones are formed under heat and pressure and this heat-only treatment can act as a continuation of Mother Nature's original design.
High Pressure High Temperature: HPHT
To alter color clarity or phenomena. Like heat-only treatments high-pressure high-temperature treatments (HPHT) mimic the natural conditions under which gemstones are formed. This combination of heat and pressure can lighten deepen or transform the color of a gem depending on the original material. The heat and pressure can also mend certain flaws or inclusions.
To improve durability and appearance. Occasionally porous gemstones are impregnated with a colorless agent or polymer to stabilize a gemstone making it more durable and suitable for lapidary work.
To alter color. In a laboratory setting a gemstone is bombarded with subatomic neutrons gamma rays or beta particles (high energy electrons) to alter the molecular structure of the gemstone material. The irradiation process is very safe and leaves no residual radioactivity in the gemstone material. Occasionally this treatment may be followed by a heating process for added stability.
To improve clarity. Typically used to enhance diamonds a high powered laser burns a hole in a colored inclusion in the stone. Then a chemical what removes the coloring agent improving the overall clarity of the gemstone.
Oiling/Resin Infusion: O
To improve clarity and surface texture. Similar to fissure filling the technique of infusing a gemstone with oil resin wax or other colorless substances improves the overall appearance of the stone. Glass and plastic are not used in the oiling/resin infusion technique.
To stabilize hardness and clarity. Stabilization is not a color enhancement. In this process excess gemstone material and clear resin are mixed and applied to the original porous gemstone material. This color matched mixture protects the gemstone while allowing it to retain its natural color.
Turquoise is a porous gemstone and the Zachery treatment is a proprietary enhancement process used to decrease its porosity. This treatment prevents oxidation and discoloration of the stone due to agents like skin oils cosmetics and sweat that the stone is exposed to during typical wear. This technique also improves the stones ability to take a good polish and may improve the stone's color.