A carat (ct) is a unit of weight used to measure diamonds and other precious gemstones. One carat is equal to 200 milligrams. As a diamond's weight increases, the cost increases, although this is not the only aspect to consider when looking for the perfect gemstone.
This unit of measurement is distinct from a karat, which is used to measure gold quality. Jewelry with more than one gemstone may have a total carat weight (tcw or tw) value rather than a single carat value. Gemstone weight is typically expressed in terms of fractions or decimal form rather than in whole numbers, a larger stones are exponentially more expensive and rare.
Facts about Carat