A guide to diamond grading: How the 4 ‘c’s affect a diamond’s appearance

You’ve probably heard of the 4 ‘C’s when it comes to diamond grading, but what do they mean, and how do they affect the appearance of a diamond?

Carat, colour, clarity and cut

The 4 ‘C’s of a diamond are its carat, colour, clarity and cut. A jewellery shop will usually give you a basic description of what these are, so you could be missing out on some vital information about your new diamond. That’s why we’ve created this complete guide to diamond grading, giving you everything you need to know about the 4 ‘C’s.

Watch the video below to learn everything you need to know about diamond grading.


You may not know, but the carat of a diamond is actually the weight of a diamond where 1 carat=0.2 grams. The word carat comes from carob seeds - where seeds were used to measure weight at markets. People used to measure their diamonds in comparison to carob seeds and that’s where the name comes from!

Most engagement rings are made with 0.2 of a carat or larger, and a 1 carat diamond is, in fact, a large stone, weighing 0.2 grams. Carats are very small weight measurements, and we understand that people have trouble picturing what a ¼ ct or a ½ ct diamond looks like. That’s why we have a chart which converts carat to mm sizes.


The colour of a diamond is graded alphabetically, starting at the letter D which is the perfect colour of a diamond - anything from J or above will be a nice white coloured diamond, but after the colour ‘J’ you’ll notice a very subtle yellow tint to the diamond.

However, it’s worthwhile noting that even diamonds in the lower colours on the scale are a very white diamond, so there may not be a need to choose a higher grade of diamond colour and you could end up sacrificing the diamond’s carat and size by choosing a higher grade in diamond colour.


Many people may have heard of the clarity scale in diamonds, but stages are very subtle so you won’t actually notice much of a difference between each scaling range.

The clarity or a ring ranges from IF (internally flawless) which has no inclusions in the diamond, to I3 where you will see black flecks which look like grains of pepper, little cracks or white ‘feathers’ which are visible with the naked eye. Inclusions that can’t be seen by the naked eye appear in VVS1 & VVS2 clarity diamonds which can only be seen (or easily be missed) when looking through a jeweller’s 10x magnifier called a loupe.


The cut of a diamond refers to how well the diamond has been cut and polished, but it can also mean the shape of the diamond itself.

The way a diamond has been cut and polished is graded on a laboratory certificate in a descriptive way from excellent to poor. Diamonds can be flawless in clarity, but poorly cut, and a laboratory report will indicate this to you.

A diamond’s cut will also refer to the shape the diamond is cut. We’ve got a great selection of round brilliant cut diamonds, (the most popular cut of diamond used for wedding and engagement rings), marquise cut, oval diamond, emerald and baguette cut diamonds.

If you’d like to see the variety of diamonds in person, you can find us in Brighton’s lanes, or you can contact us for more information about diamond grading and we’d be happy to help.

diamonds & gem stones