How to Read the Diamond Colour Scale and Clarity Grades

Short answer: A diamond’s colour is graded on a letter scale from D to Z, and its clarity on eleven grades from FL to I3. D is the most colourless and FL the most flawless stone. For most rings, G–H colour and VS clarity is a balanced choice that looks colourless and clean to the eye.

The diamond colour scale: D to Z

In a white diamond, “colour” actually measures the absence of colour. The more colourless the stone, the rarer and more valuable it is. The scale starts at the letter D and moves down the alphabet as the yellowish tint in the stone increases.

Which colour is enough?

• In a white gold setting: G–H colour looks completely white to most eyes. You only see the D–F difference side by side.
• In a yellow or rose gold setting: The warm colour of the gold reflects into the stone, so stones one or two grades lower also look white.
• In large stones: Colour is easier to notice as the stone gets bigger. At 2 carats and above, it is worth going one grade higher.

Diamond clarity: FL to I3

Almost every diamond contains tiny marks left inside it as it formed. Clarity describes the number, size and position of these marks. It is graded under ten times magnification.

What does “eye clean” mean?

If a stone’s marks cannot be seen without magnification at a normal viewing distance, the stone is called “eye clean”. VS stones and above are almost always eye clean. So the difference between VVS and VS cannot be seen when the ring is worn; it shows only under a loupe and in the price.

There is one exception: in step cuts such as the emerald cut, the inside of the stone looks open, like a window. Marks are easier to spot in these cuts, so it is worth going one clarity grade higher.

Which matters more, colour or clarity?

Both affect how the stone looks, but something comes before either of them: the cut. What makes a diamond sparkle is the quality of its cut. A well-cut G colour, VS clarity stone looks livelier than a badly cut D colour, VVS stone.

For those who want to balance their budget, the usual order is: first a good cut, then eye-clean clarity (VS), then a colour that looks white when worn (G–H), and carat last. We explain carat in what is a carat.

Frequently asked questions