Diamond Colour Grades – A Complete Beginner’s Guide
As one of the 4 C’s, Colour is very important when it comes to assessing the quality of a Diamond but what is colour when it comes to Diamonds?
That is what I’m going to cover in this post as I break down all the things you need to know about colour in Diamonds and it doesn’t matter whether you are just looking to learn or are in the process of buying a Diamond, there is some useful information in here for you.
Just so you know that this isn’t some generic post, I’m Paul Haywood FGA DGA and I’m a fully qualified Gemmologist and Diamond Grader.
What is Colour in Diamonds?
Colour in Diamonds refers to the body colour of the stone and it is split into two categories:
Let’s look at the two categories in a little more detail…
Colourless Diamonds
Over 98% of the world’s Natural Diamonds fall into the ‘colourless’ category but this is where things can get a little confusing, as only a small number of Natural Diamonds are truly colourless.
Most display some hint of colour, which is most commonly yellow but can also be brown or grey and stones are graded on how free from colour they are, not how tinted they are.
Talking of grading, there are two main grading charts, one developed by CIBJO (The World Jewellery Confederation) and the most commonly used one, which was developed by the GIA in the 1950s and ranges from D (colourless) to Z (tinted).
Why does the GIA scale start at D?
The GIA did this to break from norms, as using the letter D differentiated it from all other grading charts that start with A, which had been problematic, as sellers would market their stones as being AA or AAA quality (as is often seen with Tanzanite) and starting at D helped to stop that.
They couldn’t use a numeric grade as this was used by AGS.
Before we start looking at the colour grades in more detail, it is important to know that a Diamond’s colour is graded by looking through the pavilion of the stone not the top as this gives a true representation of the stone’s colour.
In elongated cuts like Oval and Emerald cuts, we assess the colour by looking down the length of the stone.
Diamond Colour Chart
The chart above shows the face-up and face-down colour for Diamonds and in most cases the face-up colour will be one to two grades higher than the actual colour of the stone.
Below, I will break down the main categories of colour for you to hopefully give you a better understanding of the colour grades:
D – F Colour (Colourless)
The top three grades for Diamond colour are D, E and F and all of these are colourless, meaning that there is no visible colour in the Diamond when viewed table up or from the side but if they are all colourless, then what is the difference between them?
Having looked at a fair few D – F colour Diamonds, the only way I can describe it is that D colour Diamonds look brighter than an E colour, which looks brighter than an F colour and this is something that is difficult to see in images but is noticeable when you see stones in person.
G – J Colour (Near Colourless)
The next 4 grades are classified as near colourless, meaning that there is a very faint tint of colour that can be seen in the Diamond.
Now I do have to stress that when I say a very faint tint of colour, it is very faint and this is much more apparent if you view stones in this range in person (and in the right lighting conditions) but there is a noticeable difference between a G and J colour stone.
K – M (Faint Tint)
Next we move on to the three grades that are the lower end of what is generally available on the market:
N – R (Very Light Tint) and S – Z (Light Tint)
This is kind of the no-mans land of Diamond colour as stones have a very noticeable tint but the colour isn’t strong enough for them to be a fancy colour stone.
Even though the GIA categorise these as Very Light Tint and Faint Tint, in the trade any Diamond with a grade from M to Z is referred to as a tinted.
Diamonds in this colour range are quite difficult to come across both in the trade and from retailers due to them only appealing to a small number of customers.
Fancy Colour Diamonds
The second category is Fancy Colour Diamonds, and even when accounting for all the different colours, which includes Blue, Pink and Yellow make up less than 2% of all Natural Diamonds found.
In fancy colour Diamonds, we grade the quality of the colour by looking at 3 key factors:
Saturation and Tone are combined and used to describe the Diamond, for example “Light”, “Fancy” or “Fancy Vivid”, which is then combined with the Hue to give the descriptive name for that Coloured Diamond, such as “Fancy Yellow” or “Fancy Intense Pink”.
Diamond Colour and Pricing
How does colour affect a Diamonds price?
Colour has a big impact on price and the difference in price between two colour grades (where other quality factors such as clarity and cut are the same) but how depends on which category the stone falls in:
Conclusion and Recommendations
I hope this post has helped you understand a bit more about colour in Diamonds and I’ve added a quick recap of what I covered:
But if you are looking to buy a Diamond, which colour should you go for?
And while colour is a really important quality aspect of a Diamond, I wouldn’t prioritise it over clarity or cut quality as these can have a much bigger impact on how good or bad your Diamond looks.
I'm Paul Haywood FGA DGA, the owner and founder of Haywoods Gems, I'm a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain.