What does the term "carat" measure in diamonds?

The term "carat" specifically measures the weight of diamonds and other gemstones. One carat is equivalent to 200 milligrams (0.2 grams). This unit of weight is significant in the diamond industry because it helps determine the value of a diamond; larger diamonds are rarer and, consequently, more valuable. While carat weight is often associated with the size of the diamond, it is important to note that two diamonds of the same carat weight can appear different in size due to their cut and proportions. Thus, carat refers strictly to weight rather than size, color, or clarity, which are distinct characteristics utilized in the evaluation of diamonds.