Carats: Diamond Weight
A diamond's weight is expressed in carats. Carat weight is the easiest of the four C's to determine.
To get the exact weight, however, the diamond must be loose.
One carat is divided into 100 "points" so that a diamond of 50 points is described as a half carat in size, or 0.50 carat. Within common weight ranges, there is little or no variation in per-carat price.
Diamond Education