06 Aug '26

The 4Cs: cut, colour, clarity, and carat.

The 4Cs Explained

The 4Cs, cut, colour, clarity, and carat, are the global standard for evaluating and comparing diamonds. Developed by the Gemological Institute of America, this framework provides a consistent way to understand a diamond's quality and how it will perform.

While each of the 4Cs is important, it's the balance between them that ultimately determines how a diamond looks and performs. We assess each diamond as a whole, placing particular emphasis on cut and proportion because these have the greatest influence on light performance.

Cut

Cut is the most important of the 4Cs. It refers not to the shape of the diamond, but to the precision of its proportions, symmetry, and facet arrangement.

A beautifully cut diamond will often appear brighter and more lively than a larger or higher clarity diamond with poorer proportions.A diamond with excellent colour and clarity can still underperform if the cut is poor.

Colour

Diamond colour refers to the presence or absence of visible tint. It's graded on a scale from D (colourless) through to Z (light yellow or brown tones). The less colour present, the rarer and more traditionally valuable the stone.

Colourless diamonds are often favoured for their clean, bright appearance, particularly in white metal settings. Subtle warmth can also work in favour of a stone, especially when paired with yellow or rose gold, where slightly lower colour grades can appear soft and complementary rather than noticeable. In many cases, colour differences between neighbouring grades are extremely subtle once a diamond is set.

Fancy coloured diamonds such as yellow, pink, and champagne fall outside this traditional scale and are valued for their colour intensity and rarity.

Clarity

Clarity measures the presence of internal characteristics (inclusions) and external characteristics (blemishes) within a diamond. These natural features form during the diamond's crystallisation process deep within the earth.

Clarity is graded from Flawless through to Included, depending on the visibility and impact of these characteristics under magnification.

Many inclusions aren't visible without magnification, which is why carefully selected VS and SI diamonds can offer exceptional value.

Carat

Carat refers to the weight of a diamond, not its physical size. One carat equals 0.2 grams. As carat weight increases, diamonds become rarer and more valuable.

While carat weight is often the most visible indicator of size, two diamonds of equal carat weight can look very different depending on their cut proportions. A well-cut diamond at a lower carat weight can appear larger and more balanced than a heavier stone with poor proportions.

Rather than chasing carat weight alone, we always recommend considering the overall balance between cut, proportions, colour and clarity.

The 4Cs: cut, colour, clarity, and carat.

06 Aug '26

The 4Cs Explained

The 4Cs, cut, colour, clarity, and carat, are the global standard for evaluating and comparing diamonds. Developed by the Gemological Institute of America, this framework provides a consistent way to understand a diamond's quality and how it will perform.

While each of the 4Cs is important, it's the balance between them that ultimately determines how a diamond looks and performs. We assess each diamond as a whole, placing particular emphasis on cut and proportion because these have the greatest influence on light performance.

Cut

Cut is the most important of the 4Cs. It refers not to the shape of the diamond, but to the precision of its proportions, symmetry, and facet arrangement.

A beautifully cut diamond will often appear brighter and more lively than a larger or higher clarity diamond with poorer proportions.A diamond with excellent colour and clarity can still underperform if the cut is poor.

Colour

Diamond colour refers to the presence or absence of visible tint. It's graded on a scale from D (colourless) through to Z (light yellow or brown tones). The less colour present, the rarer and more traditionally valuable the stone.

Colourless diamonds are often favoured for their clean, bright appearance, particularly in white metal settings. Subtle warmth can also work in favour of a stone, especially when paired with yellow or rose gold, where slightly lower colour grades can appear soft and complementary rather than noticeable. In many cases, colour differences between neighbouring grades are extremely subtle once a diamond is set.

Fancy coloured diamonds such as yellow, pink, and champagne fall outside this traditional scale and are valued for their colour intensity and rarity.

Clarity

Clarity measures the presence of internal characteristics (inclusions) and external characteristics (blemishes) within a diamond. These natural features form during the diamond's crystallisation process deep within the earth.

Clarity is graded from Flawless through to Included, depending on the visibility and impact of these characteristics under magnification.

Many inclusions aren't visible without magnification, which is why carefully selected VS and SI diamonds can offer exceptional value.

Carat

Carat refers to the weight of a diamond, not its physical size. One carat equals 0.2 grams. As carat weight increases, diamonds become rarer and more valuable.

While carat weight is often the most visible indicator of size, two diamonds of equal carat weight can look very different depending on their cut proportions. A well-cut diamond at a lower carat weight can appear larger and more balanced than a heavier stone with poor proportions.

Rather than chasing carat weight alone, we always recommend considering the overall balance between cut, proportions, colour and clarity.