Diamonds 4Cs - Guide to Purchasing A Diamond

19 August 2021

What are the 4 Cs Of DIAMONDs?

The 4Cs of diamonds have been developed in order to objectively compare and value diamonds through their physical characteristics; Cut, Colour, Clarity and Carat. It is a universal grading system for comparing a diamond’s quality.

Things to consider when purchasing your diamond

At Fairfax & Roberts, we recognise that choosing the perfect diamond is an important decision that lasts a lifetime. This is why we believe that the experience of selecting the diamond of your dreams is as important as the value and final creation.

We have extremely high standards when sourcing our diamonds for bespoke creations. Our staff are highly trained to look for details far beyond the cut, clarity, and colour. Fairfax & Roberts have heavily invested in training and developing their teams diamond knowledge so that you can trust we will always source the best quality stone perfectly suited to your needs.

Our commitment to quality ensures that all our diamonds are certified by internationally recognised laboratories of the highest standard, allowing you to purchase your diamond with confidence.


A diamond’s degree of colourlessness is described by a colour grading system which begins at D for truly colourless through to Z for diamonds with a more intense depth of colour. Many think of gem quality diamonds as colourless, however truly colourless diamonds are very rare. In well-cut diamonds, many of these colour differences are invisible to the untrained eye. However, they influence the value of a diamond significantly. At Fairfax & Roberts, we offer diamonds predominantly in the range from D – H, otherwise known as the colourless range.

Diamonds 4cs – guide to purchasing a diamond - Color range

Clarity & Diamond inclusions explained

Since diamonds are formed under extreme heat and pressure deep within the earth, they often contain internal inclusions (birthmarks). Clarity refers to the degree of absence of these natural inclusions. Diamonds with very few or without these birthmarks are very rare, and therefore also highly prized. These diamonds have a high clarity grade. Low clarity diamonds have larger, opaque inclusions that interfere with the diamond’s brilliance and can be visible to the human eye. The diamond clarity grading scale begins at FL (Flawless), followed by VVS (Very very slightly included), VS (very slightly included), SI (slightly included) and the Included grade (easily seen inclusions). We select diamonds of the finest clarity grade, ensuring your diamond reflects optimal sparkle and brightness. 
- Diamonds 4cs – guide to purchasing a diamond - Clarity Grade

Cut & diamond proportions

The cut grade of a diamond refers to the quality of the stone’s overall proportions, faceting and finish including the degree of polish and symmetry. Most importantly, it determines a diamond’s brilliance. In a well-cut diamond, light enters through the table (top) of the stone and travels to the side facets. As a result, it reflects light internally from one side to the other before returning light through the table of the stone as brilliance. If a diamond is poorly cut, most of the light is escaping through the lower facets of the diamond. We source diamonds of the finest quality of cut that reflects the utmost brilliance and scintillation.
- Diamonds 4cs – guide to purchasing a diamond - diamond Cut -

What is diamond carat?

The standard metric carat is the universal method of measuring the weight of a diamond. The carat is divided into 100 subdivisions called “points”. Therefore 100 points equal 1ct. All weights that are not whole units are expressed as decimals. For example, 50 points is 0.50ct, 125 points is 1.25ct and so forth. The carat weight of a diamond is often a good indicator of the stone’s size. However, diamonds of the same carat weight can also differ in dimensions, depending on the shape and faceting of the stone. 
- Diamonds 4cs – guide to purchasing a diamond - Diamond size -

Our Bespoke Design Service

At Fairfax & Roberts, we understand that an exceptional diamond needs a unique setting to capture its beauty and ensure the jewel’s longevity. Your chosen diamond deserves to be crafted into a masterpiece, and at Fairfax & Roberts, our on-premise atelier offers a bespoke service that ensures that every piece of jewellery is meticulously handcrafted around your diamond and your individual desires.

Our goal has always been to create the most beautiful bespoke jewellery using traditional tools and methods, handmade to be enjoyed for a lifetime and become precious family heirlooms.

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Learn more about Fairfax & Roberts or book a diamond & gemstone consultation