The Four C’s

Understanding diamonds requires knowledge of the four C’s: cut, colour, clarity and carat weight. It is the interplay of these various characteristics that will determine a stone’s beauty and value.


Many people think of all diamonds as white although they actually vary considerably in colour and in fact most diamonds carry a slight yellowy colour. As well as the more common stones, diamonds can also be found in deeper colours known as fancy colours, although these are very rare. Fancy colours in diamonds include yellow, green, brown, blue, orange and pink.

This is possibly the most important of the four C’s as it can mean the difference between a brilliant diamond and a dull lifeless stone. Clarity refers to the diamond’s ability to allow the passage of light through the stone without obstruction or absorption. Any inclusions inside the stone (cracks or natural features) or defects on the surface will stop light from passing through the stone and affect the diamond’s clarity. Not all inclusions are visible to the naked eye, however.

The cut of a diamond determines the brilliance of its sparkle and there are many different cuts, including round brilliant, heart shaped, pear, marquise, princess and baguette to name just a few. A well-cut diamond will reflect light to its optimum, creating brilliance and fire. Brilliance refers to the return of light to the eye through the diamond and the prism effect, the separation of white light into a rainbow of colours, is traditionally called the Fire of the stone.

Carat Weight
This C denotes the size of the stone by its weight and obviously affects the price of a diamond. Larger stones are more popular but also rarer, and therefore command a higher price per carat.