The 4 Cs Explained

Choosing the right diamond

A diamond is a salute to the precious moments in our lives, a dazzling reminder of someone’s love, a reward for a great accomplishment and an enduring symbol to be treasured and celebrated.

Diamonds are graded using a universal system that assesses the stone on its colour, clarity, cut and carat-weight, commonly known as the ‘Four Cs’. Every diamond, no matter how large or small, has a set of unique characteristics that determine its value.

Round brilliant cut diamond being viewed with a diamond scope to assess the 4 Cs and diamond grading.

The Cut

A diamond’s cut is not just a description of its shape, it is the most important factor in determining its fire, brilliance and scintillation. While nature determines the colour, clarity and carat of a stone, the cut is in the hands of the master diamond cutter.

Essentially, the cut of a diamond determines how effectively light that enters the stone is refracted within and reflected back through the top of the diamond. Factors such as proportion, symmetry and polish affect the quality of the diamond: the closer they are to perfect, the better the diamond will perform in terms of fire, brilliance and scintillation.

A diamond cut to ideal proportion and symmetry will reflect the perfect balance of light back through the top of the stone, while a poorly cut diamond will result in a loss of light, and hence sparkle, through the sides and bottom.

The Clarity

Clarity measures the presence of natural imperfections, or inclusions, in a diamond. The fewer and less visible the inclusions, the rarer and more valuable the diamond.

Inclusions are internal flaws formed under intense heat and pressure, while blemishes are surface imperfections from the cutting process. Clarity is assessed under 10x magnification based on the number, size, type, and position of these flaws.

Each diamond has a unique clarity “fingerprint.” For best value and appearance, we recommend choosing diamonds graded SI2 or higher, where inclusions aren’t visible to the naked eye.

A round brilliant cut diamond solitaire ring set in white gold being viewed and assessed with a diamond scope.
a round brilliant-cut diamond being weighed and graded for its carat weight and 4 Cs of diamond grading.

The Carat Weight

Carat refers to a diamond’s weight, with one carat equal to 0.2 grams. Larger diamonds are rarer and more valuable, so price increases significantly with carat weight.

However, carat alone doesn’t determine value—colour and clarity matter too. A smaller diamond with better quality can be worth more than a larger, lower-grade one.

Also, a 2-carat diamond weighs twice as much as a 1-carat, but it won’t appear twice as large, since carat measures mass, not size.