The unit of measurement used to determine the mass of a stone
A Carat is the unit of measurement used when weighing a diamond. One carat is the equivalent of 0.2 grams. A diamond's value is greatly determined by its weight. For example if you had two identical diamonds i.e. same colour, clarity and cut but the one weighs 1 carat and the other only half a carat, the 1 carat diamond may be worth as much as 350% more than the half carat!