A diamond's color greatly impacts its overall appearance. But with diamonds, it's all about what you can't see. The most precious and rarest of diamonds are colorless or very close to it. A diamond's facets act like prisms, reflecting light into a wide spectrum of hues. This characteristic is known as a diamond's "fire". If a diamond has noticeable color, this can greatly reduce its ability to reflect light. So a diamond which has a lower color grade will not display the same fire and translucence as a higher color grade stone.
Most commercially sold diamonds have color grades which typically run from colorless to near-colorless. Some may have slight tints of yellow or brown.
The GIA Color Scale
The Gemological Institute of America Color Grading Scale is the preeminent standard by which diamonds are graded for color. The diamond color scale begins at D (colorless) and goes all the way to Z (light yellow). It can be difficult to discern a diamond's color when it is face-up so most gemologists prefer to evaluate a diamond face-down against a pure white background. They also use carefully controlled lighting while comparing the diamond to master stones of a specific color. Diamonds can only be compared to other diamonds.
Color distinctions can be so subtle that they are virtually invisible except to a highly trained professional diamond grader. But even a seemingly slight color variation can make an enormous difference in the quality and value of a diamond.
The various color grades for diamonds are:
- D (Colorless). This is the highest-quality color grade. A diamond which receives this grade is extremely rare and has an unparalleled brilliance. For obvious reasons, these diamonds are also the most expensive.
- E (Colorless). This color grade contains only the smallest traces of color. A diamond graded "E" is also rare and possesses an exquisite brilliance.
- F (Colorless). This is a very high-quality color grade. Tiny traces of color can only be detected by a trained diamond grading expert.
- G, H (Near Colorless). This color grade of diamond contains noticeable color only when compared to D, E, or F graded stones. A G or H color graded diamond usually appears colorless to the untrained eye. It is generally considered an excellent value.
- I, J (Near Colorless). A diamond graded either I or J contains only a slight amount of detectable color. These are also considered an excellent value since they appear almost colorless to the average person.
- K, L, M (Faint Yellow). Only faint color is visible. These grades of diamonds can still be quite beautiful and often emit significant fire.
An often-asked question is why the GIA color grading system begins with D and not A. Before the GIA developed and introduced the D-Z Color Grading Scale, many different systems were haphazardly used by the jewelry industry to grade a diamond's color. Letters, numbers, Roman numerals and different terminologies were all used at some time. The results from using all these various grading systems were reports that were inconsistent and inaccurate. The GIA decided to take a fresh approach and begin its Color Grading Scale with the letter D. Unlike in school, this D grade is very much sought-after and signifies the very highest quality!