Gemstone Treatments

Treatments refer to any process other than cutting and polishing that improves the appearance of the color or clarity, or that are used to alter the appearance, durability, value, or supply of a gemstone.  Some of these methods are widely accepted in the trade today, while other methods are not. The accepted trade methods are the ones that change the color of the gemstone permanently.

All reputable gem dealers fully disclose gem treatments. In our view, it is important to provide buyers with detailed information so that they know exactly what they are buying. So we have provided some information below that will help educate you about the common treatments.  Keep in mind that most colored gemstones are treated, and this is a perfectly legitimate practice as long as all facts are disclosed to the buyer. If you know the facts, then you can feel safe about buying a gemstone that you will enjoy for many years to come.

There are some gemstones that would not even exist if it were not for treatments. The abundance of citrine, in shades of yellow, gold and orange is the result of heat treating amethyst.   Tanzanite in shades of violet and blue depends on heat treatment to produce enough supply to meet the demands of the public.  Pink topaz is another example of a gem that would not be available without heat treatment. Not only are these treatments acceptable, they are necessary to keep these products affordable and available.

Recent demand for unheated sapphires and rubies has caused a price increase of as much as 50%-100% for unheated material. Does this mean that the untreated gem is more beautiful? NO! In most cases the heating enhances the gemstone to make it more beautiful; the price premium is the result of the rarity of being unheated.

Here are a few examples of the most used treatments:

[su_box title=”Heating” style=”noise” box_color=”#2E85AE”]The heat treatment of gems is the most common treatment technique used on gems. Reference to heat treatment of gems is found in gemological literature dating back more than one thousand years. However, widespread use dates back only about fifty years. Unlike most gem treatments, heat treatment is not detectable in most gem varieties including aquamarine, citrine and tanzanite. This treatment is usually detectable in ruby and sapphire. Heat treated gems are stable and the treatment is usually permanent. The vast majority of gemstones are heated to alter their color. In ruby and sapphire the treatment is often performed to improve color and clarity. The alteration usually involves burning out secondary colors present in an attempt to improve the appearance.[/su_box]

[su_box title=”Fracture Filling” style=”noise” box_color=”#2E85AE”]Clarity enhancement/Fracture filling refers to the filling of surface breaking cavities or fissures with a colorless glass, plastic or similar substance. This process is done to improve durability, color and transparency and may add weight.[/su_box]

[su_box title=”Dyeing” style=”noise” box_color=”#2E85AE”]Dyeing refers to one of the oldest treatments recorded. The treatment involves the introduction of a coloring agent into a gemstone to give it a new color, intensify an existing color or improve color uniformity.[/su_box]

[su_box title=”Flux Healing” style=”noise” box_color=”#2E85AE”]This process is a form of heat treatment that is typically encountered with ruby. During heat treatment fluxes, or in some instances heat alone, is used to induce the healing of fractures by partial melting and controlled cooling of the stone during which a nutrient rich solution develops in the fractures and crystallizes as the stone cools, thus healing the fracture.[/su_box]

[su_box title=”Irradiation” style=”noise” box_color=”#2E85AE”]Irradiation refers to the use of neutrons, gamma, ultraviolet and/or electron bombardment to alter a gemstone’s color. The irradiation stage of the process is then usually followed by a heating phase to effect the change. Blue topaz is typically produced by irradiation. [/su_box]

[su_box title=”Oiling” style=”noise” box_color=”#2E85AE”]Oiling refers to a filling of surface reaching cracks or fissures in a gem with a colorless oil or resin, wax or other substance except glass or plastic, to improve the gemstone’s appearance. The purpose is to diminish the visibly of fractures and thus improve transparency in the stone. The treatment is usually not permanent.[/su_box]