Fancy color is not to be confused with fancy shape – they have little to do with each other. Fancy shape designates all the different diamond cuts that are not round brilliant cuts, regardless of color. Fancy color on the other hand, designates a diamonds color in relation to the traditional color scale used for colorless diamonds. Most of the diamonds that are extracted from the earth are in the colorless to light yellow range (D to Z grade).
Fancy color diamonds go off this scale, as they have a distinct and opulent color. Unlike colorless and near colorless diamonds which are valued for their lack of color, fancy color diamonds are valued precisely for the intensity and distribution of theirs. These diamonds are extremely rare and tend to be found mostly as small stones weighing less than a carat. For every 10,000 colorless diamonds of gem quality, only one natural color diamond will have made the trip from the depths of the earth to its surface. It is the entirely natural process of geological formation which ensures that each natural color diamond is unique.
The formation of natural color diamonds requires not only the special conditions necessary for the creation of all diamonds, but also the presence of additional trace elements and distortions to the typical diamond crystal. If an element interacts with carbon atoms during the creation of a diamond, the diamond’s color can change. Radiation and pressure on a diamond’s structure will also have an impact on its color. Read more about the origin of color here.