Every diamond is unique, yet jewellers around the world describe them using the same four characteristics: cut, colour, clarity and carat weight. Understanding the 4Cs will not turn you into a gemmologist overnight, but it will help you ask the right questions, compare stones fairly and spend your budget where it matters most.
1. Cut – the source of sparkle
Cut describes how well a diamond has been proportioned, polished and finished — not its shape. A well-cut stone takes light in through the top, bounces it between its facets and returns it to your eye as brightness (white light), fire (flashes of colour) and scintillation (sparkle as it moves). For round brilliant diamonds, cut is graded from Excellent through Very Good, Good and Fair to Poor.
Our advice: if you prioritise one C, make it cut. A beautifully cut diamond can look larger and livelier than a heavier stone with poor proportions.
2. Colour – the absence of colour
White diamonds are graded on a scale from D to Z. The less body colour a stone has, the rarer it is.
- D, E, F – colourless
- G, H, I, J – near colourless
- K, L, M – faint
- N to R – very light
- S to Z – light
Our advice: G and H diamonds appear icy white once set, especially in white gold or platinum, and offer outstanding value. In yellow or rose gold, an I or J stone can look equally lovely.
3. Clarity – nature’s fingerprints
Almost every diamond contains tiny natural features formed deep within the earth. Clarity grades describe their size, number and visibility under 10x magnification. There are eleven grades: FL (Flawless), IF (Internally Flawless), VVS1–VVS2, VS1–VS2, SI1–SI2 and I1–I3.
Our advice: most people cannot see the difference between a VS2 and a Flawless diamond with the naked eye. A stone described as “eye-clean” gives you the look of perfection for a fraction of the price.
4. Carat – weight, not size
Carat is a unit of weight: one carat equals 0.2 grams, and each carat is divided into 100 points, so a 0.75ct diamond may be called a “75-pointer”. Because larger diamonds are rarer, price rises sharply as weight increases.
Our advice: prices tend to jump at popular weights such as 0.50ct and 1.00ct. Choosing a beautifully cut 0.90ct stone instead of a 1.00ct can save a meaningful amount, with virtually no visible difference once on the hand.
Bringing the 4Cs together
No single grade tells the whole story. The most beautiful diamond for you is the one that balances all four characteristics within your budget — and speaks to you when you see it. That is why we always show clients several stones side by side, under magnification and in natural light, and supply an independent grading report with every centre diamond from 0.30ct.
Ready to see the 4Cs in real life? Book a private consultation and we will prepare a shortlist around your taste and budget.
See every grade side by side in our visual Diamond Chart.
