The carat measurement describes the diamond's weight. As the weight increases, the value of the diamond increases (assuming all other characteristics are equal). Diamonds are weighed according to the metric carat system, in which one metric carat equals 0.2 grams. One carat can also be expressed as 100 points. Therefore, one-half carat is referred to as fifty points. The weight of the diamond, combined with its dimensions, is important in identifying the value of a diamond.