Of the four grading factors - Clarity, Colour, Cut and Carat weight, the three factors - Clarity, Colour and Cut are graded. The fourth - Carat weight is not graded but simply measured. The unit of weight used for diamonds is the metric carat. A metric carat equals 0.200 grams. A carat is divided into 100 equal units called points or cents. Thus a 10 pointer or a 10 cents diamond would weigh 0.10 carats.
Sometimes diamonds are also weighed in terms of grains where 4 grains equals 1 metric carat.A diamond is weighed on an electronic device called the diamond balance. Some of these balances have the option of weighing in carats and grams. We, here at, E.G.L. use a diamond balance, which can weigh gems from 0.001 carat up to 500 carats.