Four Cs for quality

Diamonds are typically characterised by what are known as the four Cs, which refer to cut, colour, clarity and carat.

Cut

A good cut can display a diamond's fire and brilliance to its best advantage. Fire refers to the breaking up of white light into its spectral colours; brilliance, or lustre, is the amount of light reflected back from the surface of the stone.

Colour

A diamond can range from totally colourless to light yellow, on a scale starting with the letter D, the highest grade, and proceeding alphabetically through E, F, G and so on. Diamonds also come in a range of 'fancy colours' - blue, green, red, pink, yellow and brown - which are rare and expensive.

Clarity