Diamond Weight

As with all diamonds and colored gemstones, the weight—and therefore the size—is expressed in carats. The carat originated as a natural unit of weight: the seeds of the carob tree. Diamonds were traditionally weighed against these seeds, however, the system was later standardized and one carat was fixed at 200 milligrams (1/5 of a gram).

One carat is divided into 100 "points" so that a diamond of 25 points 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 two diamonds of equal size can have unequal prices, depending on their cut, color, and inclusions, diamonds of quality can be found in all size and price ranges.