This is the diamond’s physical weight measured in metric carats. One carat equals 1/5 gram and is subdivided into 100 points. Carat weight is the most objective of the 4Cs. It involves no estimates, comparisons, or judgments. All that is required is a precisely balanced scale capable of weighing extremely small weights. Yet, despite the ease of measurement and the relative unimportance of diamond weight, there are some facts you should understand about weight and price.

Comparing the value of diamonds by weight is like comparing the value of paintings by size. A wall-sized canvas by an unskilled artist may be bigger than a miniature by Rembrandt, but it will not be worth more. Large diamonds are more rare than smaller ones, and as the carat weight increases, the value of the diamond rises. However, the increase is not proportionate to the size. For example, a one-carat diamond will cost more than twice that of a 1/2-carat diamond (assuming Color, Clarity, and Cut are identical). Weight does not always enhance the value of a diamond, either. Two diamonds of equal weight may be unequal in value, depending on other determining factors such as Cut, Color, and Clarity. In fact, if a diamond is improperly cut, the added weight may serve only to reduce its brilliance. For these reasons, you should consult an American Gem Society™ jeweler regarding the weight, quality, and value of a diamond.