Carat is often confused with size even though it is actually a measure of weight. Sometimes, you might think a larger diamond appears more brilliant than a smaller one. This is because light must travel a greater distance through a large diamond. the result is the prism effect that your eye registers as more brilliance and fire.

One carat is equivalent to 200 milligrams. One carat can also be divided into 100 “points.” A .75 carat diamond is the same as a 75-points or 3/4 carat diamond.

Larger diamonds are found relatively infrequently in nature and are therefore more valuable.

A 1-carat diamond costs exactly twice the price of a half-carat diamond, right? Wrong. Since larger diamonds are found less frequently in nature, a 1-carat diamond will cost much more than twice as much as a 1/2-carat diamond, assuming color, clarity and cut remain constant.

Cut and mounting can make a diamond appear larger (or smaller) than its actual weight. So shop around and talk to your jeweler to find the right diamond and setting to optimize the beauty of your stone.

The term carat is a derivative of the word carob. Carob seeds are surprisingly similar in weight to one another; thus they were used in ancient civilizations as the reference tool to measure the weight of a diamond. One carob seed eaqualed 1-carat.

Many people confuse carat and karat. Carat refers to the weight of a diamond while karat refers to the purity of gold (not the weight). You might see a 1-carat diamond set in 18 karat gold, for example.