Diamond Colour Actually Means Lack of Colour

Understanding what diamond colour means helps in choosing the right diamond. Interestingly, the diamond colour evaluation of most gem-quality diamonds is based on the absence of colour. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA’s D-to-Z diamond colour-grading system measures the degree of colourlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones of established colour value.

Many of these diamond colour distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price. Hence, it is important to get a GIA expert’s opinion in evaluating the best colour for your diamond.

WHY DOES THE GIA COLOUR GRADING SYSTEM START AT D?

Before GIA universalized the D-to-Z Colour Grading Scale, there was no clear standard to define what diamond colour is. A variety of other systems were used loosely, from A, B, and C (used without clear definition), to Arabic (0, 1, 2, 3) and Roman (I, II, III) numbers, to descriptive terms like “gem blue” or “blue white,” which are notorious for misinterpretation. So, the creators of the GIA Colour Scale wanted to start fresh, without any association with earlier systems. Thus the GIA scale starts at the letter D. Very few people still cling to other grading systems, and no other system has the clarity and universal acceptance of the GIA scale.

ARE DIAMONDS GRADED AS Zs CONSIDERED FANCY-COLOUR?

No. Naturally coloured diamonds outside the normal colour range are called fancy-colour diamonds. The FTC provides no guidelines for the use of the term “fancy-colour” in the US, but there is general agreement in the international trade about what diamond colour range is customary for fancy-colour diamonds. These are either yellow or brown diamonds that have more colour than a Z master stone or they exhibit a colour other than yellow or brown.