The term carat originates from the ancient practice of weighing diamonds against the seeds of the carob tree. The system was eventually standardized with one carat fixed at 0.2 grams. Each carat is sub-divided into 100 points, so a quarter-carat diamond is 25 points or 0.25 carat. Although the carat is a unit of weight, not size, the carat weight of a diamond has come to refer to particular sizes. If properly cut, diamonds of the same weight should be about the same size. These sizes dont apply to other gems, however, because specific gravities vary widely among gemstones. |
