Understanding the diamond colour grading scale

A diamond’s value is determined by the 4 Cs: carat, cut, clarity and colour. For colourless diamonds (as opposed to coloured diamonds), the diamond industry has adopted an alphabetical scale from D to Z, with D being the highest grading. As you go down the scale, the diamond starts to develop a yellow tint.

Diamond experts determine the colour by comparing a diamond against a master set of diamonds of different colours. Therefore, without comparing diamonds side by side, it is difficult to see the difference between grades. However, it plays a vital role in determining the price of the jewel.

In this guide, we will cover the following topics to give you a better understanding of the role colour plays in the value of a diamond:

• DEF colour graded diamonds

• GHI colour graded diamonds

• Colourless vs coloured diamonds

Below, we provide a brief breakdown of diamonds graded DEF on the colour scale. These are considered ‘premium’ colour grades and are, therefore, highly sought-after. But, they are also more expensive than lower-graded diamonds.

Colour grade D diamond: D is the highest on the diamond colour grading scale, indicating that the stone is completely colourless (or white). D colour diamonds are rare and come at high prices.

Colour grade E diamond: The difference between a D and an E colour graded diamond is not typically noticeable from the naked eye of a non-expert. In fact, it would only be visible to an expert gemologist in a lab using master stones for comparison. Nevertheless, E graded stones are usually slightly cheaper in price.

Colour grade F diamond: F grade diamonds are the lowest of the premium colourless diamonds. However, most people are not able to easily discern between DEF colour graded diamonds.

Beyond the near-colourless scale, diamonds develop a slightly more visible tint. However, it is critical to understand that a colourless diamond with a yellow tint is not the same as a yellow coloured diamond, which is rare.

Natural fancy colour diamonds are found in nature with their exceptional colours. It is this natural phenomenon that makes them special. While all diamonds were created underneath the earth’s surface, some were exposed to additional elements that altered their structure. This unique alteration comes across through stunning colours, such as blue, which stems from the element boron, or yellow, which is caused by nitrogen.

While colourless diamonds receive a score of D to Z on the colour grading scale based on their yellow or brown tint, fancy colour diamonds are graded on the intensity of the colour — and the rarer the colour, the steeper the price.

Remember, colour is just one of the 4 Cs and should be considered along with the other factors that influence a diamond’s quality.

BNT Diamonds buys diamonds straight from the source to offer you the best quality diamonds at the best price. In addition, all our diamonds have passed through a renowned certification agency, such as GIA, HRD or IGI.

If you are interested in buying diamonds — whatever their position on the colour grade scale — as a value investment, contact our expert team today.