Fancy Colored Diamonds
GIA does not grade fancy colored diamonds on the colorless diamond color-grading scale. They instead use a scale that rates the diamond's color on three primary characteristics: Hue, Tone and Saturation.
The Hue in color grading refers to the primary and notable colors that are present in the diamond, such as Pink, Blue, Yellow, Brownish-Yellow, and so on. GIA recognizes 27 hues in grading fancy colored diamonds.
The Tone of color grading refers to the lightness or darkness of the hue, or primary color of the diamond.
Saturation is the measure of how strong and intense the primary color of the diamond actually is, such as light, deep, intense or vivid.
The 9-grade GIA color grading scale runs as follows:
- Very Light
- Fancy Light
- Fancy Dark
- Fancy Deep
- Fancy Intense
- Fancy Vivid
This grading scale measures how the level of color saturation is found in a given fancy colored diamond. It is also important to note that when a fancy colored stone is being graded it is viewed from the top down, as opposed to the normal grading method for colorless diamonds (which are looked at with the bottom, or pavilion up and the top, or table, down).
In recent years fancy colored diamonds have gone from being interesting oddities and curio pieces to being immensely sought after and greatly desired gems in their own right. Many of the world's most famous diamonds (such as the South African mined 128.54 carat, canary-yellow Tiffany diamond, brought out in 1877) have been fancy colored diamonds. This mixture of history and celebrity has only increased the current desire for fancy color diamonds.
The very color of fancy colored diamonds also makes them more difficult to cut properly. Fancy colored diamonds have their own demands for the diamond cutter, in that the diamond cutter is not cutting to produce the same effect that is sought after in colorless diamonds. In the case of fancy colored diamonds, the main goal of the diamond cutter is to preserve and enhance as much of the natural color of the diamond as is possible.
Therefore, it is to this end that the cutter must strive to facet and polish the diamond to facilitate the entering light to produce the most vivid display of the diamond's color. In the end, the goal in cutting a fancy colored diamond is not to produce maximum scintillation or fire, although these are desired, but to bring out the most color. The very nature of the fancy colored diamonds preclude them from being particularly exceptional in brilliance and fire, as many wavelengths of the entering light are being absorbed by the diamond's color producing agent, whether this be foreign matter, irregular crystal growth or radiation.