Even the slightest change in diamond color can affect the quality and value of a diamond. Although most diamonds are thought of as colorless (that is, not fancy-colored), most colorless diamonds actually contain hints of brown and yellow. These differences in color are often very subtle –  so subtle that an untrained eye can’t tell the difference between a nearly colorless diamond and a colorless one. Yet these minute variations in what color a diamond is can have a significant impact on the purchase price of the stone.

All non-fancy diamonds sent to GIA for grading are graded according to GIA’s internationally recognized D-to-Z color-grading scale, with D representing the top end of the scale, as a completely colorless diamond, and Z the bottom end of the scale, representing the obvious presence of a light yellow or brown hue. Each letter in the scale denotes a combination of tone (lightness or darkness) and saturation (intensity), creating a value called “depth of color.”

In order to determine what a diamond’s color is, the diamond is viewed table down, under highly controlled lighting conditions. It is compared to a set of carefully assembled master comparison diamonds (“master stones”) where each natural diamond corresponds to an alphabetical grade from D to Z.  This grading protocol ensures that the grade assigned is precisely the letter designated by GIA for that color.

Although each letter in the GIA D-to-Z color scale designates a specific color range, letters are also grouped into broader categories:

  • D through F: Colorless. These diamonds are the most chemically pure of the D to Z range.
  • G through J: Near colorless. Coloration often unseen except by trained graders. Very valuable.
  • K through M: Faint. Coloration still difficult to see by the untrained eye.
  • N through R: Very light. Coloration can be seen in larger stones by untrained eye.
  • S through Z: Light. Colorations can be seen in many sized stones. Distinctly yellow or brown but not so colored to be considered a “fancy” diamond.

Overall, the important thing to remember is that the lower the letter, the higher the grade, and the more valuable your diamond.

If you are wondering what are diamond colors designated as fancy color diamonds, please click here to learn more about these remarkable diamond colors. Diamonds with naturally occurring colors can be incredibly rare. Pink and yellow diamonds are highly sought after, and green or blue diamonds  are especially prized. Fancy color grades should be expertly assigned to these unique and rare diamonds. The value of a diamond is significantly impacted by the color of the diamond so be sure you know to learn what color is a diamond and how that impacts its value.

*Color Grading “D-to-Z”Diamonds at the GIA Laboratory, Gems & Gemology, Winter 2008