Guide to Diamond Carats

Carat weight is one of the 4Cs of diamonds that measures measures a diamond’s weight and size. The term "carat" is derived from the carob seeds that were used to balance scales in ancient times.

Today’s metric carat is equal to 200 milligrams, or one-fifth of a gram, and there are approximately 142 carats to an ounce. Carats are further divided into points. There are 100 points in a carat. A half-carat diamond may be referred to as a 50-point stone.

Because large diamonds are rare, they generally have a greater value per carat. When considering the value of a diamond or gemstone, two diamonds or gems of equal carat weight can have differing price points based on the quality of cut, color and clarity -- the three other diamond quality factors. A professional jeweler, like a member of Jewelers of America, is educated to distinguish and explain the various diamond quality factors so you find the highest quality diamond that fits your budget.