Carat, abbreviated "ct." is a measure of weight used for diamonds. One carat is equal to 1/5 of a gram (200 milligrams). Stones are measured to the nearest hundredth of a carat. A hundredth of a carat is also called a point. Thus a .10 carat stone can be called either 10 points, or 1/10 of a carat. Small stones like .05, and .10ct are most often referred to by point designations. |
| The carat, as a unit of weight, is derived from the carob seed which was used by early gem traders to weigh diamonds. Since a carat is a unit of measure and not size, two diamonds of the same carat weight may appear to be different sizes depending on how the diamond is cut. (Pictures of different diamonds according to weight) |
