COLOURLESSNESS
Colour Explained

Diamond colour is all about what you can’t see. Diamonds are valued by how closely they approach colourlessness – the less colour, the higher their value. (The exception to this is fancy colour diamonds, such as pinks and blues, which lie outside this colour range.) Most diamonds found in jewellery stores run from colourless to near-colourless, with slight hints of yellow or brown.

A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. The 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 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.

BY THE LETTER

Before GIA universalized the D-to-Z Colour Grading Scale, 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.

Diamond Colour Grading by GIA

This short video explains the GIA colour scale and how GIA classifies a diamond with a letter grade from D-to-Z by comparing it to masterstones representing the colour grades on the GIA scale.

Diamond 4Cs