Diamond 4C's, Order of Imporantance

When choosing a diamond, the gradings of the 4 C's can often be overwhelming. Our diamond experts are often asked the order of importance of a diamond’s cut, colour, clarity and carat weight. Finding the highest quality diamond that you can is especially important when obtaining a diamond for an engagement ring. Referencing the GIA scale of diamond grading, this easy guide will help you to decide the best balance of grades for your budget.

In theory, each of the 4 C's carry an equal bearing in the quality of the diamond that you are purchasing. The higher the grades and carat weight of the diamond, the rarer it is and therefore the more valuable it is. However, in all our years of guiding clients through the process of purchasing a diamond, we have placed the 4 C's in order of importance to ensure that you can purchase the most beautiful diamond for your price range.


We would argue that the cut of the diamond is the most important of the 4 C's. The cut grade is the only grade that is not natural, and is dependant upon the way that the stone is faceted and polished from the original crystal.

The cut grade of the diamond refers to the skill and precision in which it has been faceted. The diamond can be any shape, from round brilliant, to a fancy cut, to a step cut. If the cut of the diamond is poor, the sparkle, scintillation and fire will be compromised.

Round brilliant cut diamonds are graded for cut by gem laboratories, and these grades range from excellent to poor. The symmetry, proportions and polish of the stone are all considered when giving a diamond a cut grading. Ideally, a round brilliant cut diamonds facets should fall within a scientifically calculated range of proportions to ensure the optimum amount of brilliance and sparkle of the stone.

Unfortunately, fancy cut diamonds are not graded by laboratories for cut. Despite this, there are similar ranges of proportions for fancy cut stones. A poor cut in a fancy cut stone can result in the ‘bow tie’ effect, in which the central portion of the stone is dulled. It is also important to inspect the symmetry of the diamond yourself, particularly with fancy cuts, with cuts such as the heart cut, pear cut and marquise cut, it is easy to tell asymmetry of the outline by imagining a vertical line slicing the stone in half and comparing the two sides.

We are happy to advise on the quality of the cut of each of the diamonds we sell. The cut is such an important feature of the stone and the diamond’s fire, brilliance and scintillation depend upon it. Our diamonds are sourced and faceted by expert craftsmen, so you can purchase your diamond safe in the knowledge that the cut is of an exceptional standard. 


Colour is an immediately noticeable component of the 4 C's. As it is such an obvious feature of a diamond, our customers tend to already have an idea of the colour that they desire. All other factors being equal, the more colourless the stone, the more valuable it is. It is worth noting that diamonds with a D colour, particularly in larger sizes, are very rare. When weighing up the 4 C's, colour is a factor that can be compromised to a degree in order to achieve the optimum combination for your budget.




Face up colourless, face down colourless.


Face up colourless, face down colourless.


Face up colourless, face down colourless.


Face up colourless, face down colourless.


Face up colourless, face down slightly tinted.


Face up colourless, face down slightly tinted.


Face up colourless, face down slightly tinted.


Face up slightly tinted, face down obviously tinted.


Face up slightly tinted, face down obviously tinted.

M – Z

Face up obviously tinted, face down obviously tinted.


Face up obvious colour.


On the GIA scale of colour grades, it is only at the H grade where a slight tint of colour can be seen when the diamond is viewed face down. This means that if you desire a ‘colourless’ stone, you are not just restricted to a D colour grade. When set in jewellery, any grade from D to H will appear colourless.

Some clients prefer to have some warmth in the colour in their diamond. The colour of your diamond is all down to personal preference. Colours from I to L display a warm and often flattering hue, and look spectacular in yellow gold settings.

For a definite tinted colour, anything from L to Z will provide a definite colour face-up. We would recommend if you are after a coloured diamond ring, contact our team about fancy coloured diamonds. We would be happy to advise you on coloured diamonds that have a strong enough hue, tone and saturation to be called fancy coloured.


Clarity is another of the 4 Cs that can be highly noticeable. The clarity of a diamond references the internal imperfections or external blemishes of a diamond. A heavily included diamond can affect the beauty and even the durability of the stone, so it is an important factor to consider.





No inclusions or blemishes seen under 10x magnification.

Internally Flawless

No inclusions and insignificant blemishes seen under 10x magnification.


Inclusions are extremely difficult to see under 10x magnification


Inclusions are very difficult to see under 10x magnification.


Inclusions are difficult to see under 10x magnification.


Inclusions are somewhat difficult to see under 10x magnification.


Inclusions are easy to see under 10x magnification.


Inclusions are very easy to see under 10x magnification, may be seen with the unaided eye.


Obvious inclusions, the beauty and durability of the stone are somewhat affected.


Obvious inclusions, the beauty and durability of the stone are seriously affected.


Obvious inclusions, the beauty and durability of the stone are very seriously affected.


It is worth referencing the GIA clarity grading scale for clarity that runs from the cleanest grade, Flawless, to the most included, Imperfect. This scale provides a guide for the appearance of the diamond under 10x magnification. However, it is not until the clarity grade SI2 in which inclusions can be seen with the naked eye. All clarity grades above an SI2 have inclusions that are only visible with 10x magnification.

Once you are wearing your diamond ring, it would be very peculiar for the diamond to be examined with an eye loupe! Therefore, for a diamond that appears clean to the unaided eye, we would recommend a stone with a clarity grade of SI1 or above.

It is worth considering, though, that clarity imperfections within the stone can disrupt and sometimes block the passage of light in and out of the stone. Clarity grades of VS2 and above contain only minor inclusions that shouldn’t interrupt the brilliance and fire of the diamond too much, retaining that all important sparkle.

If you would like a step cut diamond, such as an emerald cut or an Asscher cut, we would recommend selecting a diamond with as high a clarity grade as you can. The large table facets on the emerald cut and Asscher cuts act as a window into the stone, and so any inclusions are incredibly easy to see in these stones. Conversely, in a brilliant or fancy brilliant cut, the fire and dispersion of these cuts can often disguise clarity errors. The step cuts are famed for their ‘hall of mirrors’ effect that means any clarity imperfections will be easier to notice.


Carat weight should be the very last consideration of all the 4C's. It is far better to focus on obtaining the diamond with the most radiance and beauty than a large stone that is dull. We would always recommend a smaller diamond that sparkles incessantly with a good colour than a large diamond that is obviously included, with little to no brilliance and an unsightly greyish brown colour.

If the appearance of a larger size diamond is important to you, there are ring design options that can make the diamond appear larger. For example, fancy cut diamonds in elongated shapes such as pear, oval and marquise shape diamonds appear larger than a round brilliant cut for their carat weight. This is because most of the weight in these elegant shapes is stored in the crown and table facets, giving them a larger surface area face up.

As well as this, a narrower ring band can create the illusion of a larger principal stone. A bezel setting, particularly in a white metal can also increase the perceived diameter of the diamond. If that is not enough, a halo setting, anywhere from single to triple can drastically increase the size of your diamond visually.

To conclude, it is important to know your preferences before searching for a diamond. Whichever order you personally place each of the 4 C's, getting the best diamond possible is always a compromise between the four, namely because D colour, Flawless, large stones with an excellent cut grading are not only incredibly rare, but incredibly costly. It is always recommended to attain the highest quality diamond that is affordable. A poorly cut stone will not showcase the diamond’s unique optical properties effectively. A highly included stone can affect the diamond’s durability in the long run. As well as this, a tinted stone will be obvious when compared to other diamond jewellery. We would always urge our clients to balance the cut, colour and clarity grades first before considering the carat weight.

For further information on the 4C's, or assistance in finding the perfect diamond for you, contact our team of diamond experts who will be happy to help. Call us on 01335 453 453 or email us at sales@britishdiamondcompany.com.