Colored Diamonds

Making the Grade
Color grading fancy-colored diamonds is a complex process of assessing the color of a diamond in three dimensions: hue (the aspect that gives the color its name - like red, green, or blue), tone (the lightness to darkness of the color) and saturation (the strength or purity of the color). First, GIA's professional graders determine color grades by comparing diamonds side-by-side in a controlled lighting and viewing environment. [GIA Fast Fact]

GIA recognizes 27 hues for color grading diamonds. This places a practical limit on the number of possible color descriptions and creates terminology that's precise enough for GIA's gem laboratory, but accessible and understandable by the public.

Each of the 27 hues represents a range of colors. The 27-hues consist of basic colors like red, blue, and green, and mixed colors like orangy red, green-blue, and greenish yellow. In the GIA system, the predominant hue is stated last.

From Faint to Fancy - Looking Beyond Color
Then, after the diamond color is determined, specific terms ranging from Faint to Fancy Vivid are used to describe the combined affect of tone and saturation on that color. Accompanied by color terms like blue and pink, these grades are used on colored diamond reports, such as the ones done for each of the diamonds featured in the Splendor of Diamonds Exhibit. Now when you see, “GIA Color Grade: Fancy Vivid blue” as appears with the Heart of Eternity – you'll know exactly what that means.

GIA uses specific grades to identify the ranges of color appearance. They are: faint, very light, light, fancy, fancy dark, fancy intense, fancy deep and fancy vivid in varying degrees of saturation from lower to higher.

For fancy colored diamonds, the grading is performed by viewing the color with the diamond positioned face-up. The grading is an assessment of the "presence of color".