Most people compare carat weight to size. The larger the diamond the more it weighs. As with all precious stones, the weight-and therefore the size-of a diamond is expressed in carats. The word carat originated from the carob tree or Ceratonia siliqua.

One carat is divided into 100 "points" so that a diamond of 25 point is described as a quarter of a carat or 0.25 carats. Size is the most obvious factor in determining the value of a diamond, but now you know that two diamonds of equal size can have very unequal prices depending on their quality. However, remember, that diamonds of high quality can be found in all size ranges. For an easy comparison of price and size, see the table below. Prices are approximate and based upon D Color, internally flawless, excellent cut.