The four key criteria for getting your perfect diamond

JEWELLERS use the universal four Cs – carat, colour, clarity and cut – to describe a diamond’s characteristics and assess its value.

Carat is simply a measure of weight, not size as commonly thought. One carat (1 ct) equals 0.20 grams and is divided into 100 points, half a carat, for instance, can be described as a 50 pointer diamond. It is important to remember that a diamond is not valued by carat weight alone and two diamonds of equal carat weight can have very different values.

Fancy coloured diamonds are the rarest, and are prized among connoisseurs. Polished diamonds are graded for minute variations in depth of colour, from “colourless” to “light colour”. This is universally known as the D (exceptional white) to Z (tinted colour) colour scale.

Nature ensures that every diamond is unique and as individual as the person who wears it. Naturally-occurring features, known as inclusions, appeared while the diamonds were forming in the earth. Clarity measures the diamond’s purity; it refers to how free a diamond is from these tiny blemishes and inclusions. The clarity scale goes from flawless (no inclusions at all) to included (many visible inclusions).

Cut refers to the shape and proportions of the diamond. Round, princess and emerald are some of the most familiar – with rounds being the most popular. Cut is the factor most involved in the sparkle of a polished diamond and is expressed in terms of the brilliance, fire and scintillation. To maximise sparkle, a diamond must be cut to very specific parameters with a strict attention to the polished finish of the diamond.

The size and shape of the diamond you choose, combined with personal style, will create a different overall effect from person to person. Brilliant-round diamonds are quite traditional whereas choosing a marquise or pear-shaped diamond will create a more modern, contemporary look.

There are a huge variety of diamond designs to choose between, but remember that your diamond should be one that you feel an affinity with.

Gareth Jones is the diamond expert from Forevermark, the diamond brand from De Beers Group.