A diamondās cut refers to how well it has been shaped and faceted to interact with light. It isnāt about the shape ā like round or oval ā but rather the quality of the angles, proportions, and finish. A well-cut diamond reflects light in a way that maximises its brilliance, fire, and scintillation: so this is what to look out for.

The Anatomy Of A Diamond #
To appreciate the intricacies of a diamondās cut, it helps to know its basic parts:
- Table:Ā The flat top surface of the diamond.
- Crown:Ā The upper portion above the girdle.
- Girdle:Ā The widest part, forming the boundary between crown and pavilion.
- Pavilion:Ā The lower part beneath the girdle.
- Culet:Ā The tiny point at the very bottom (or sometimes, in the rarer cuts, a flat facet).
The angles and proportions between these facets determine how light interacts with the diamond ā how it bounces the light around to create the most sparkle and brilliance.
How Diamond Cuts Are Graded #
There are a few different ways diamonds are graded, with scales that are tweaked between institutes (hello, GIA, IGI etc). These grading criteria evaluate:
- Proportions:Ā The relationship between a diamondās facets and angles, which affects how light is reflected and refracted.
- Symmetry:Ā The precision of facet alignment. Symmetry ensures light interacts evenly across the diamondās surface.
- Polish:Ā The smoothness of the diamondās surface, which directly influences its ability to reflect light.
Cut Grades #
You will often see diamond cut and diamond shape used interchangeably, but they are two very distinct meanings. Diamond cut refers to theĀ qualityĀ whereas diamondĀ shapeĀ refers to the pattern/arrangement of the diamond ā for example, an emerald cut, a round brilliant, or a heart shaped.
The diamondās cut holds the key to its brilliance. Cut grades are evaluated with meticulous precision, offering clarity to buyers and ensuring you know exactly what youāre getting ā before you drop your money on it.
šš¼ An āExcellentā cut is the pinnacle, it doesnāt get any better. These are the diamonds that dance with light, reflecting brilliance, fire, and scintillation at their finest. We donāt tend to work with diamonds that donāt have this grade.
šš¼ A step below, āVery Goodā cuts still impress, with subtle differences in polish or proportions that hardly dim their radiance. Essentially, to the untrained eye, a āVery Goodā will give you just as much as an āExcellentā.
š«³š¼ The āGoodā grade, while still appealing, may let a little light escape, softening the sparkle ā weād recommend you stay away from these.
šš» Meanwhile, āFairā cuts reveal more obvious imperfections in symmetry or polish, and āPoorā cut stones, unfortunately, lack the brilliance youād expect from a diamond, appearing dull and lifeless. And with so many wonderful diamonds on the market, weād recommend you donāt even consider these.
Letās Talk Numbers #
The quality of a diamondās cut impacts its price more than many realise. Two diamonds with identical clarity, color, and carat can differ significantly in cost: all because of the cut. Why?
A well-cut diamond delivers sparkle ā what many would argue is a stoneās most captivating feature. Itās worth every penny to ensure your diamond doesnāt just sit pretty but shines brilliantly.
So, how do you find the right cut for you? We always prioritised quality ā āExcellentā or āVery Goodā grades are your safest bets and we will only work with āexcellentā. And remember, the light test never lies: a well-cut diamond will dazzle under direct light, no matter what.
Want to learn more about the 4Cs or explore our range of lab-grown diamonds?Ā See our ringsĀ orĀ book a consultationĀ with our diamond experts today.