Colour

Grading > Diamond Colour

In the late 1950's GIA (The Gemological Institute of America) introduced the colour grading system that is used today. The GIA grading system replaced grades such as Top Wesselton and Capes and is internationally accepted. In most cases, unlike all other gems, it is the absence of colour that makes the stone more valuable. With the exception of "Fancies", or fancy coloured diamonds, which are rare, all diamonds are graded on the scale shown below. Most diamonds are either a light yellow, light brown or light gray. The separation between grades is almost undetectable to the untrained eye.
An analogy would be five pieces of white paper of differing qualities. Looked at Individually they are all look white, but when placed side by side the distinction can be made.

Diamond colour chart

Trained Gemologists will grade diamonds in a loose table down position using comparison stones and properly controlled lighting to make their judgments. The same specialist will be able to grade a set stone within two colour grades, although to the inexperienced grader the colour in a diamond will be virtually indiscernible until the stone reaches a "J". Even a "J" colour diamond will appear white when mounted and face up. The value in a stone changes dramatically with each colour grade.

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