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The 4Cs Of Diamonds: Clarity, Cut, Carat & Colour

The 4Cs Of Diamonds: Clarity, Cut, Carat & Colour

If you’ve ever bought a diamond - or are currently shopping for the perfect diamond engagement ring - then you’ll have no doubt heard the 4Cs mentioned. The 4Cs of diamond buying measure the quality of the diamond, and stand for:

  • Cut
  • Colour
  • Clarity
  • Carat

While diamonds are eternal, the 4Cs are actually a relatively recent addition to the grading of diamonds. Robert M. Shipley, the founder of the Gemological Institute of America (GIA), introduced the 4C diamond scale in the 1940s to give the industry some consistency. And it worked – today, the 4Cs of diamonds are used to grade all diamonds.

The 4Cs apply to lab grown diamonds in the same way as natural diamonds.

  • The 4Cs measure how high quality a diamond is, which can impact its value
  • They were brought in to provide consistency to diamond grading
  • The 4Cs of diamonds apply equally to lab grown diamonds as natural ones

Why are the 4Cs in diamonds so important?

The 4Cs of diamonds help define the quality – and therefore the value – of a diamond. The better the 4C grade, the higher the value. The 4Cs are used across the industry to certify a diamond. Each one of the 4Cs plays its part in identifying the value of a diamond.

A diamond that scores well on all four of the measurements, will cost more. Though, a diamond with a higher carat and poor colour will usually still be more expensive than one that has perfect colour but a low carat rating.

What is diamond clarity?

Clarity in diamonds is a measurement of how many imperfections there are in the make up of the diamond. As one of the 4Cs of diamonds, clarity measures and grades these ‘inclusions’. Diamonds with more inclusions, will have a lower clarity score. We can measure these on a diamond clarity chart.

Read more about the diamond clarity scale.

What is diamond cut?

In the 4Cs of diamond, cut refers not to the shape of the diamond but if it’s been cut in a way to maximise sparkle. The cut is about using symmetry, proportions and polish to maximise the way light interacts with the stone. A diamond setting type can also impact how the light shines within the diamond. 

We go into more detail about diamond cuts in our guide.

What is diamond colour?

Colour, in relation to the 4C’s, refers to the lack of colour in a diamond. The closer to ‘colourless’ a diamond is, the higher its colour grade. 

Find out about diamond colour grading in our guide.

What is diamond carat?

In the 4Cs, a diamond with a high carat is graded as the most valuable – if all other factors are equal. Diamond carat means the weight of the diamond – which also corresponds directly with the size. 

Find out how carats are measured in our in-depth guide to diamond carats.


The 4Cs provide both jewelers and shoppers with information on the quality of diamonds. They can be used to judge certain aspects of a diamond’s make up and play a part in the value of the diamond. Once you know the 4Cs of diamonds, you can start to talk about what is important to you when you’re buying a diamond.

Speak to our team to discuss your diamond needs or browse our range of lab grown diamonds today.


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