We are seeing an increase in the popularity of fancy colored diamond lately and have sold several rather large stones in the recent past. In discussing the stones with our clients it becomes more and more apparent that there is much more mystery and mis-information surrounding these diamonds than traditional white diamonds. With that in mind, I am posting this article to help you understand what qualified something as a fancy colored diamond.
In diamonds, rarity equals value. With diamonds in the normal range, value is based on the absence of color, because colorless diamonds are the rarest. With fancy color diamonds—the ones outside the normal color range—the rarest and most valuable colors are saturated pinks, blues, and greens. In all cases, even very slight color differences can have a big impact on value.
Compared to fancy yellows and browns, diamonds with a noticeable hint of any other hue are considerably more rare. Even in light tones and weak saturation, as long as they show color in the face-up position, they qualify as fancy colors. Red, green, and blue diamonds with medium to dark tones and moderate saturations are extremely rare.
Grading fancy color diamonds is complex and specialized, and it takes highly trained laboratory graders to complete the process accurately.
The GIA system for color-grading fancy color diamonds is designed to accommodate the fact that not all colored diamonds have the same depth of color. For example, yellow diamonds occur in a wide range of saturations, while blue diamonds do not.
Fancy color diamonds have a range of color strength with the intense and vivid colored diamonds being the most rare.
Diamonds with red or reddish colors are extremely rare and highly valued. Pure pinks are more popular than diamonds that are purplish, orangey, brownish, or grayish. Trade professionals market some very attractive stones in this category as “rose-colored,” and some stones with purplish tints as “mauve” diamonds.
Blue diamonds are extremely rare. They generally have a slight hint of gray, so they’re rarely as highly saturated as blue sapphires. Their color is caused by the presence of boron impurities—the more boron, the deeper the blue.
With fancy color diamonds, color is the dominant value factor. Even diamonds with numerous inclusions that result in a low clarity grade are prized by connoisseurs if they display attractive face-up color. Of course, inclusions that threaten the gem’s durability can lower a fancy color diamond’s value significantly.
Size and shape are two aspects of cut that can influence diamond color. The larger a diamond is, or the deeper its pavilion, the farther light can travel in it. This can often lead to a richer, more intense color.
The style of the cut can also influence color. Cutters discovered that certain styles—typically mixed cuts like the radiant—can intensify yellow color in diamonds that are toward the lower end of the D-to-Z color-grading scale. When carefully fashioned as radiant cuts, many yellow-tinted stones—at one time called “cape” by the trade—can become fancy yellows when viewed face up. This perceived improvement in color increases the price per carat. As an added benefit, the radiant style provides higher yield from the rough than a standard round brilliant.
As with diamonds in the normal D-to-Z color range, large fancy color diamonds are rarer and more valuable than small ones.
Treated Fancy Colored Diamonds
It is important to note that there are many fancy colored diamonds that are on the market today that have been treated to alter their color. The treatments include irradiation and coating the stones to give them the fancy color. Treated, fancy colored diamonds have very low desirability on the secondary market and are often misrepresented as natural color diamonds. If you are considering a purchase of a fancy colored diamond it is very important that you know that it is natural color. Most natural fancy colored diamonds will be accompanied by an origin of color report by a recognized Gemological Laboratory. The labs include; The Gemological Institute of America (GIA); The American Gemological Laboratory (AGL); the Gemological Certification and Assurance Lab (GCAL) or the American Gem Society Lab (AGS).