BUYING A DIAMOND

There are various criteria you need to consider when buying a piece of diamond jewellery. These qualities are the four C's - the cut, the clarity, the colour and the carat.

Cut

The cut of the diamond refers to the angles and proportions that diamond cutters create in the stone to polish it and maximise its brilliance and is the only one of the diamond's defining qualities that is not created by nature.

A classic round cut diamond is cut to 58 facets. Diamonds can also be marquise, heart, emerald, princess, pear and oval shaped.

A round cut diamond is as it sounds, a diamond cut into a sphere. Marquise is a brilliant-cut diamond, meaning that it reflects the most light from within the stone. Marquise cut is boat-shaped, long and thin with gently curved sides that come to a point on either end. A heart cut diamond is as it sounds, as is a pear shaped and oval diamond - all are brilliant cut. Emerald cut is a rectangular or square-shaped cut-cornered diamond and princess cut is a square or sometimes rectangular-shaped modified brilliant-cut diamond.

A poorly cut diamond, either cut too deep or too shallow, will allow the light to escape and it will not sparkle as effectively.

Clarity

Diamond is a natural substance, and each diamond is different, so naturally the majority of diamonds contain “inclusions”, or tiny flaws; think of them as the diamond's birthmarks. These inclusions can be minute feather shapes, clouds and tiny crystals that are formed when the diamond is forming in the earth. Inclusions stop the light being refracted as effectively out of the diamond, thus making a difference to its brilliance.

The clarity of a diamond is judged by the quantity, size, position, colour, release and shape of its inclusions. The fewer the inclusions, the greater the quality and corresponding value of a diamond.

The range of clarity is divided into grades. IF (Internally Flawless) means the diamond has no visible characteristics under magnification, or that no flaws are visible. VVS means that the diamond is Very, Very Slightly Included, VS1/2 means that minor characteristics are visible under magnification, SI1/SI2 means that the diamond is slightly included, or that characteristics are visible under magnification, and I1, I2 and I3 mean that characteristics are visible with the naked eye. The numbers mean that the diamonds can be graded more precisely, as each number represents levels within each grade. The 1s will have fewer or smaller inclusions than the 2s.

Diamonds with no inclusions are referred to as flawless and are extremely rare.

Colour

Diamond colour is judged on a scale established by the Gemological Institute of America (GIA) and the range is from D (colourless and therefore extremely valuable), through Near Colourless, Slightly Tinted, Very Light Yellow, Light Yellow, Yellow, to Light Fancy, which is graded at around a Z.

Even diamonds that appear colourless and seem simply to refract other colours than to have their own intrinsic colour have a slight yellow, brown and grey tinge that experts can identify. The colour can add a character to a diamond - some of the world's most beautiful diamonds have colour in them.

You must also consider the setting you would like for your diamond - Geraldonline offers diamond rings in both yellow and white gold settings and a small range in platinum.

Carat

A diamond's value is not judged by its size but by its weight, which is measured in carats. The word comes from the plant carob - in ancient civilisations carob seeds were used to compare weight with diamonds.

Carats can be broken into 100 points, so a 0.5 carat diamond can also be referred to as a 50 point diamond, or half a carat. Not all diamonds of the same carat will cost the same - the quality of the other three c's, the cut, clarity and colour, all have to be the same also.

The fact that a diamond is large should only be considered in terms of the other c's - a large stone of poor cut, clarity and colour will not be worth more because of its size. A large stone of excellent cut, clarity and colour though will be worth more than a smaller diamond are more rare.