Fancy colored diamonds are gaining popularity among shoppers and investors at an astounding pace. In recent years, huge colored diamonds like this vivid pink pear cut had been consistently making headlines in record breaking auctions.
In contrast, the smaller stones are marketed through online channels to reach more audiences on a global scale. It is also interesting to note that the demand for fancy colored diamonds are getting fueled from an increasingly affluent consumer market.
Unlike the colorless diamonds we see in everyday jewelry, fancy colored diamonds can easily cost 10-20 times more than another stone of the same size. If you are in the market of buying a fancy colored stone, it is imperative that you understand how a diamond’s color impacts its overall value.
On a fundamental level, this knowledge boils down to making sense of how fancy colored diamonds are graded in the labs. Do note that the grading process for colored diamonds is totally different from the normal methodology applied for diamonds in the D-Z range?
In this article, we’ll go over the grading process used by GIA, the industry’s most recognized grading laboratory and hopefully this will give you insights to understand what you see on a grading report.
When it comes to buying fancy colored diamonds, GIA is the only lab you should trust. Other labs have lax grading standards and often fail to detect treatment processes! Diamonds with GIA reports are also easier to sell as traders and jewelers trust them.
Image credit: Gemological Institute Of America
When a colored diamond is being graded, the first thing that is done is to establish its face-up color against a neutral grey background (Note: D-Z diamonds are graded face-down). Once the basic color of the diamond (e.g. blue, red, yellow etc..) is determined, comparisons of that representative color will be made against a set of predefined reference diamonds.
The GIA grading system makes use of color space areas which is split into ‘boxes’. In each of these boxes, reference stones for the specific color and hues are neatly organized and framed. The diamond being graded will then be placed in one of these boxes for comparison in order to find a color characteristic that closely matching its own.
Once a match is found, the diamond will be classified using the description of the color space where it is placed. As you can see, the implementation of the grading methodology is done in a standardized manner such that the grading results obtained are repeatable. For example, once a grader has determined the terminology used to describe the diamond, another grader should arrive at the same terminology if he/she grades the stone separately again.
GIA’s fancy color grading system is based on 3 main attributes of tone, hue and saturation.
Hue refers to the primary color of the diamond such as pink, yellow, blue, brown etc… In total, GIA recognizes 27 different hues and each of these hues have a range of possible colors.
Tone defines how dark or light the hue of the diamond is.
Saturation refers to how intense the coloration of the diamond is.
The GIA color grading system uses nine grades to distinguish color ranges. These are: Fancy Vivid, Fancy Intense, Fancy Deep, Fancy Dark, Fancy, Fancy Light, Light, Very Light and Faint. For fancy colored diamonds, the general rule of thumb is that the stronger the hue, the more valuable the stone becomes.
The grades assigned are based on the overall effects of the diamond’s hue, tone and saturation.
Note that warmer color hues like orange or yellow gradually appear to look brownish as their saturation decreases. On the other hand, cooler shades like blue tend to gravitate towards greyish colors.
Sometimes, diamonds can have more than one color hue in its body. In such cases, the dominant color is always described last. Here are some real-life examples to illustrate this in more details. To see full product specifications, simple click on the images.
Can you see the differences between “yellowish green” (left) and “greenish yellow” (right)?
In some cases, diamonds can even have a third or fourth color. However, the same rules still apply that the primary color is stated last.
Diamonds with multiple colors: Grayish yellowish green (left) and brownish greenish yellow (right)
In a nutshell, the GIA grading system describes color in an objective manner which is understood and accepted throughout the world. When it comes to fancy colored diamonds, every little detail matters because it can mean the difference between thousands of dollars.
That is why I only recommend buying colored diamonds with grading reports from GIA and never from unreliable labs like IGI or EGL.