carat

Definition

Unit of weight for diamonds and other precious stones, equal to 200 milligrams (4 jeweler's grains or 0.007 ounce) or about the weight of a small paper clip. One carat is divided into 100 points (each equal to 2 milligrams): a 1.15 carat diamond, for example, weighs one carat and 15 points (230 milligrams). Typically, a one carat brilliant-cut diamond has a diameter of about 6.5 millimeters or one-quarter of an inch. A ruby is denser, therefore smaller than a diamond of the same weight. The carat, however, is only one of the four factors that determine the value of a diamond, the other three are its clarity, color and cut. Also called metric carat to differentiate it from the traditional carat that was equal to 207 milligrams. Spelled as karat in Germany.