As one of the most popular gemstones to make the trend scene, brown diamonds summon images of luxury and pleasure with names like champagne, chocolate, and cognac. Browns are the most plentiful colored diamonds mined, accounting for 80% of the yield unearthed at Australia's Argyle mine. The brown color is caused by internal parallel grain lines in the diamond.
Yellow Diamonds contain trace elements of nitrogen, and are the second most abundant fancy-color diamond. Hgihly-saturated yellow stones are the most desirable color.. You will sometiems hear yellow diamods referred to as "canary", though this is not an accepted term used in grading yellow diamonds.
The pink color ranges from soft, clear pink to reddish purple. Pink diamonds get their color from graining inside the crystal; the more graining the more color. This can also produce red diamonds, though they are extremely rare.
Also quite rare, blue diamonds are caused by boron impurities in the crystal - the more boron, the deeper the hue. Blue diamonds have traces of grey, so they never approach the deep saturated color of sapphires.
The presence of radiation causes green diamonds, which can happen when diamonds form near radioactive rocks. The green color is mainly in the surface, not through the entire stone. Natural green diamonds are very rare, low in saturation and somewhat greyish.
Colored Diamond Grading Standards
GIA established color grading standards and terminology specifically for color diamonds, based on the color's hue, tone, and saturation. This grading standard, combined with GIA's ability to determine whether color is natural or the result of an artificial process, has made GIA colored diamond reports the benchmark for captivating gems.
Color diamonds are graded on a scale from Faint to Fancy Deep. The entire spectrum is as follows:
Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark, Fancy Deep
Faint, Very Light, and Light apply to all colors except yellow. A yellow stone with one of those grades is still considered a diamond that falls between the D-Z color range of white diamonds.