Fancy brown color diamond compared beside a colorless diamond.
As people around the world become more affluent, fancy colored diamonds have seen a spike in popularity among shoppers and investors. In recent years, huge colored diamonds like this vivid pink pear diamond have often been making headlines in record-breaking auctions.
Unlike the colorless diamonds that we typically see in everyday jewelry, fancy colored diamonds are often sold unmounted and can cost 10-20 times more compared to a colorless diamond of the same size.
When it comes to determining the value of a fancy color diamond, the color tone, hue and saturation of the diamond are the key factors that affect its price. So, if you are planning to buy an expensive fancy colored diamond, it is imperative that you understand how things work.
In this article, we’ll go over the grading process used by GIA, the industry’s most recognized grading laboratory. Hopefully, this will give you insights to help you understand what you see in a grading report and help you make better purchase decisions.
Let’s jump right in…
The GIA colored diamond scale.
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 to find a color characteristic that closely matches its own.
GIA reference color chart for pink diamonds showing color transitions.
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: 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 has 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.
When it comes to buying fancy colored diamonds, GIA is the only lab you should trust. Other labs often have lax grading standards and do not have the proper equipment to detect treatment processes! If you don’t want to get ripped off, NEVER buy a colored diamond that isn’t graded by GIA.
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.
Grades are assigned based on the overall effects of 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 detail. To see full product specifications, simply 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 that 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.