A diamond’s weight is measured in carats, abbreviated ct. One carat can be divided into 100 points. Therefore, a diamond weighing one quarter of a carat can also be referred to as being 25 points.
A diamond’s colour is determined on a colour scale from D (colourless) to Z (yellow/brown). The most sought after diamonds have no colour. Whilst most diamonds appear to have no colour, in actual fact they have tints of colour as shown on the colour scale.
Refers to the amount and size of natural imperfections in the diamond. This may be internal (inclusions) or external (blemishes). The fewer inclusions in a diamond, the rarer and more valuable the gem.
This does not refer to the overall shape of the diamond but rather the quality of the cutting. It is the single most important aspect of any diamond. The proportion, finish and symmetry of the external facets of the diamond are what creates the fire and brilliance. A diamond may be colourless and flawless but if it is not cut well it will appear dull and lifeless.