Most people have never even heard of coloured diamonds. Almost all of the publicity and advertising for diamonds is slanted towards convincing consumers that white, or more accurately colourless, is the only desirable colour for diamonds, and that diamonds with a slight tinge of yellow or brown are less attractive and therefore less desirable.
About Diamond Color
The Color of a diamond refers to the tone and saturation of color, or the depth of color in a diamond. The color of a diamond can range from colorless to a yellow or brown hue. A more colorless diamond is rarer and more valuable because it appears white and brighter to the eye. The most respected system used today for evaluating diamond color was developed by the Gemological Institute of America, (GIA).
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Even though there are several grades in each category, there are slight differences between the letter grades. D is the clearest and most valuable, X is a dingy yellow and least expensive. Z grade-colored diamonds are the rarest and most expensive. A diamond so saturated with nitrogen that it becomes a deep, rich yellow is as rare as a colorless diamond.