Gemstone treatments/enhancements explained

Published by Gordon Weller GIA GG on 15th Feb 2014

Although cutting and polishing a gemstone are the most basic forms of enhancement used to fully display the beauty of a gemstone, man has developed numerous treatments and methods to improve upon or duplicate nature’s work.

Treated gemstones are globally accepted. It is estimated that more than 95% of the popular gemstones have some form of treatment. Many treatments are common and are accepted in the gem and jewelry industry. These processes can range from simple heating (sapphire and ruby) to a combination of techniques, such as irradiation and heating to create blue topaz. Below are recognized forms of enhancements in the jewelry and gem industry. 100 East Fine Jewelry does not use gems that have been enhanced by some of these methods. To learn which specific treatments the gemstones used in our jewelry receive, read our blog entitled 'Potential Gemstones Treatments We Use' or better, yet, refer to the Product Detail page for each item.

Assembled Products - multiple layers or combinations of manufactured and/or natural materials are joined together to create a gemstone.

Bleaching - the use of chemical agents to lighten or remove a gemstone’s color. Some gemstones are bleached and then dyed.

Coating (aka Surface Coating or Surface Modification) - a substance (backing, coating or coloring agent) is applied to the surface of a gemstone to alter or improve its appearance or to provide color or other special effects.

Diffusion (aka Lattice Diffusion) - the exposure of a gemstone to high temperatures and specific chemicals which allows penetration of color-causing elements into the gem's matrix, producing color changes or phenomena.

Dyeing - the introduction of colored dyes into a gemstone to add, change or intensify color or to increase color uniformity.

Fracture Filling (aka Cavity Filling) - the intentional filling of surface-reaching cavities or fractures usually with glass, plastic or polymers to reduce their visibility or to improve durability, appearance and/or add weight.

Heating – exposing a gemstone to rising temperatures to change its appearance (alter color, clarity and/or phenomena, etc).

Heating and Pressure (HPHT and LPHT) – heat and pressure are combined to alter the color or clarity of diamonds

Imitation with man-made products - the use of fabricated materials such as glass, ceramic or plastic to imitate or resemble the appearance, but not duplicate the characteristic properties, of a natural gemstone.

Irradiation – bombardment with neutrons, gamma or electrons to alter or improve a gemstone’s color. Irradiation may be followed by a heating process.

Laser - the use of lasers and possibly chemicals to alter or remove inclusions in diamonds.

Oiling/Resin Infusion - filling surface-breaking cavities with a colorless oil, wax, natural resin or unhardened man-made material (not glass, plastic or polymers) to improve appearance.

Quench Crackling – purposely heating and quickly cooling a gemstone to create fractures and cracks which allows it to accept dye to create a new color

Synthetic Gemstones - man-made materials which have essentially the same optical, physical and chemical properties as a naturally occurring counterpart.

Waxing/Oiling - the impregnation of a colored wax, paraffin and oil in opaque, porous gemstones to improve their appearance.