Color in diamonds is most often the result of nitrogen and boron impurities; occasionally the color of a diamond is the result of structural defects within the diamond crystal. The presence of dispersed nitrogen within a diamond may cause the diamond to exhibit a yellow color. The presence of boron may cause the diamond to be blue in color, like the Hope diamond. Pink, red, and purple diamonds are believed to be the result of pink graining (lamellae) or deformation of the diamond structure which results in pink coloration in what would otherwise be a colorless diamond. It is believed that most green diamonds are green because of natural irradiation or hydrogen impurities. Black diamonds are colored by the presence of an abundance of graphite inclusions.
Fancy colored diamonds are always cut to compliment the depth of the color and not necessarily visual performance, thus the concept of “ideal proportions” can not be assigned to diamonds of fancy colors and intensities. Fancy colored diamonds are valued by carat weight, clarity and the depth or intensity of their color like this:
The deeper and more intense the natural color of the diamond, the rarer and more valuable that it is.
At present there are three types of fancy colored diamonds available in the market:
While it is a natural inclination to decide that a “natural, untreated fancy colored diamond” is the only option to consider when you fall in love with the depth and beauty of a natural blue colored diamond, the reality of prices starting in the range of one hundred thousand per carat for visibly included qualities can be a bit of an eye opener to people just becoming familiar with the fancy shape diamond market. Natural, treated and lab grown fancy colored diamonds provide consumers outside of Hollywood with access to “the look” for a more reasonable price.