Gemstone Treatments

Bleaching: To lighten or remove color in a gemstone or to remove dark inclusions.

Coating: Artificial enhancement to the surface of a gemstone or mineral.

This practice improves a gemstone or mineral’s appearance (gold, pyrite, indium, titanium, niobium and copper are the most commonly used elements for surface coatings.)

Some Examples:

• Aqua Aura Quartz: Quartz is a natural mineral; the coating that creates the iridescent metallic sheen is a surface enhancement treatment.

• Mystic Topaz: Topaz is a natural mineral. The coating enhances its color or creates an iridescent metallic sheen on a surface. The process sometimes involves a layer of titanium applied to the bottom of a gemstone (known as the pavilion).

• Coated Tanzanite (A newer treatment): This treatment process involves a thin layer of cobalt added to the surface of low-grade tanzanite material. This improves the color to the sought-after bright violet-blue or blue-violet color.

Dyeing: A colored agent of oil, chemical, or polymer is applied to the surface or impregnated into a gemstone or mineral to enhance the color. Many times this process is done prior to a gemstone being faceted. Lapis, jade, malachite and onyx are the most popular minerals to receive this type of treatment.

Diffusion Treatments: A combination of chemicals and high-temperature methods used to enhance color.

Fracture Filling: A process of filling fractures and cracks with resin or colorless lead glass to improve durability, color, and transparency. It’s a common and trade-acceptable treatment for emeralds.Occasionally this treatment, known as clarity enhancement, is used in low-grade diamonds.

Heating: The most common type of treatment. It also occurs naturally in the earth. This is one of the most permanent treatments-- it has many positives since it can stabilize and improve a gemstone’s color. Sapphires, rubies, and tanzanite are the most common gemstones heated by human intervention.

Irradiating: Gemstones can be artificially irradiated by gamma, ultraviolet and/or electron bombardment to alter and enhance a gemstone’s color. Blue topaz color is a common example of the result of irradiation.

Impregnation: A process of filling fractures and cracks with a clear or colored liquid, wax or plastic in an airtight or vacuum system, that allows the substances to fill the voids in the gemstone. This commonly used on lapis and jade.

Oiling: This process is used to improve the visual appearance of feathers, cracks and fracture inclusions. The oils used are commonly cedar oil, palm oil, and even olive oil. Note: This treatment is NOT permanent. Once the oil is injected into the stone, the oil stays liquid, yet can come out or be removed by thoroughly cleaning the stone and through the use of an ultrasonic cleaner. Oiling is commonly used on emeralds.

There are many different types of gemstone and mineral treatments. Many are consumer and industry-accepted and commonly used. Some are harmless, while others can be harmful if not disclosed properly.