Diamond Cut

Diamond cut refers to the arrangement of a diamond’s facets. For many people, it’s the most important of the 4Cs. A diamond’s cut is often mistaken as meaning its shape (oval, pear, etc), but a diamond’s cut grade is actually about how well the facets interact with light. The best diamond cuts reflect the most light – if a diamond is poorly cut there will be dull spots where the light isn’t reflected. So cut greatly impacts a diamond’s brilliance, which affects its sought-after sparkle. Even diamonds with the highest colour or clarity grade will appear dull if poorly cut.



A diamond will lose up to 50% of its original carat weight in the cutting and polishing process but it is an essential step to ensure the rough diamond reaches its full potential.


The only cut recognised by the GIA is a round brilliant, which makes round brilliants the popular cut and considerably higher in price than others. Because cut has a dramatic effect on how light performs when it strikes the diamond, it affects price hugely. A well-cut, well-proportioned diamond with a good finish creates a dazzling display of light and is therefore considerably higher in price and value than a less well-cut diamond.


The GIA identifies five cut grades: Excellent (EX), Very Good (VG), Good (G), Fair (F) and Poor (P).

Diamonds with an Excellent cut grade have an even, proportioned pattern with good contrast between light and dark areas. This results in a beautiful sparkle with reflections appearing crisp and well balanced. Poorly cut diamonds, on the other hand, offer nearly no sparkle, brilliance or fire. Light escapes out of the bottom and sides of the stone, creating a dull appearance. A well-cut diamond has a magical quality.

buying tips

The cut is what makes a diamond beautiful, so don’t underestimate its importance. Many jewellers sell large, poorly cut diamonds at a ‘bargain’ price. They’re not really a bargain, they’re just not as good. So, for the best brilliance and sparkle, we recommend only buying Good cut diamonds or above.

Higher diamond cuts are worth the extra money. We say use more of your budget on the cut than on other aspects such as colour. Remember cut equals beauty.

Still confused?

We’re here to help. We’re diamond experts and will guide you through the entire buying process to help you make an educated, informed and confident decision.