Carat is often confused with size even though it is actually a measure of weight. The cut of a diamond can make it appear much larger or smaller than its actual weight.

High carat diamonds often appear to be brighter or more brilliant than their lower carat siblings due to the prism effect of light traveling over larger distances. However, carat is merely one of the factors to take into consideration when appraising the quality of the stone.

The Hancock Diamond, weighing less than one carat, famously sold for $880,000 at Southeby's in 1987, due to its very rare red color.