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Diamond Grading: The 4 C’s

Diamond Grading: The 4 C's

Everybody loves diamonds. The sparkle and light reflection that you get with a diamond is truly something else. However, did you ever notice that some diamonds sparkle more than others? Or even look slightly off colour to the diamonds you are used to seeing on TV? In truth no two diamonds are the same. Today let’s take a quick look at the basics of diamond grading. 

Jewellers use a system of diamond grading known as the 4 C’s. The 4 C’s this phrase refers to are clarity, colour, cut and carat. These factors are used to give a valuation to diamonds. Let’s take a quick look at each of these factors and how they are used to evaluate diamonds.


The first C we will talk about is clarity. This refers to the amount of inclusions that feature in the diamond. Inclusions are imperfections in the diamond which can range from clouding, graining and even small crystals which can form in the diamond. It’s a diamonds inclusions which make each one unique and individual. It is actually extremely rare to find a diamond without any inclusions and these diamonds are the ones you will pay top money for. 

Clarity is graded on a GIA scale with 11 diamond clarity grades which are flawless, internally flawless, 2 very very slightly included categories, 2 very slightly included categories, 2 slightly included categories and 3 included categories with the flawless category being most expensive and the 3rd included category being the least.

GIA Clarity Scale


3 different coloured diamonds

Colour as the name suggests, means the color of the diamond. Diamonds are not always clear or colourless, they can also come in yellow or brown. In fact, truly colorless diamonds are very rare and will cost you the highest premiums and any hints of colour obviously devalue the diamond. 

The colour of a diamond is graded on the GIA colour scale which ranges from D – Z with five different sections which categorise the quality of the diamond. The lowest on the scale is light which ranges from S – Z which identifies the more coloured diamonds. Then we have “very light” which ranges from N – R on the scale and “faint” which ranges from K – M. The two clearest grades of diamond are “near colourless” which ranges from G – J and “colourless” which is the top of the chart, ranging from D – F. The chart below should give you a better understanding of the GIA colour chart.

GIA Colour Scale



The way a diamond or any gemstone reflects the light is crucial to its sparkling and radiant appearance. This is why the way the gemstone has been cut is so important to its value. If a diamond is cut in a way that dulls that sparkle, it will obviously have a negative effect on the value of the diamond. 

These light reflections are determined by the quality of the angles, facets, proportions and overall finish of the diamond. These factors are most commonly graded on a scale of ideal, excellent, very good, good, fair and poor. This is not to be mixed up with the term brilliant cut as this refers to a round cut diamond. The shape of a diamond, (for example heart cut) is also referred to as the cut but in this case it is more applicable to the facets and so on. Although certain cuts in this sense of the word can have a great impact on a diamonds light reflection.


By nanana_nono on pixabay

Carat refers to the weight of the diamond and is usually measured to a thousandth of a carat and 1 carat is the equivalent of 0.2 grams. Obviously the heavier the diamond the more expensive it will be but this is especially true when comparing two diamonds of similar clarity, colour and cut grades.

That is it for our basic introduction to the 4 C’s of diamond grading. Hopefully you will now have a bit of a better idea what to look for when you are out shopping for diamond jewellery to make sure you get the best bang for your buck. If you have enjoyed this short blog post, please give this post a like, share with a friend you think would like to see this and/or leave a comment to let us know if this post has helped you or not and if not how we can improve our future posts. 

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