Diamond Enhancement - Color Enhancements

Color Enhancements

Generally there are three major methods to artificially alter the color of a diamond: irradiation with high-energy subatomic particles; the application of thin films or coatings; and the combined application of high pressure and high temperature (HPHT). However, there is recent evidence that fracture filling is not only used to improve clarity, but that it can be used for the sole purpose to change the color into a more desirable color as well.

The first two methods can only modify color, usually to turn an off-color Cape series stone (see Material properties of diamond: Composition and color) into a more desirable fancy-colored stone. Because some irradiation methods produce only a thin "skin" of color, they are applied to diamonds that are already cut and polished. Conversely, HPHT treatment is used to modify and remove color from either rough or cut diamonds—but only certain diamonds are treatable in this manner. Irradiation and HPHT treatments are usually permanent insofar as they will not be reversed under normal conditions of jewelry use, whereas thin films are impermanent.