An 'international carat' of 205 milligrams was proposed in 1871 by the Syndical Chamber of Jewellers, etc., in Paris, and accepted in 1877 by the Syndical Chamber of Diamond Merchants in Paris.

Precious stones are weighed in carats; a single carat is equal to 200 milligrams. Carat is also a variant spelling of karat, which measures the purity (but not the weight) of gold.

CARAT definition: 1. a unit for measuring the weight of jewels (= precious stones) 2. a unit for measuring how pure…. Learn more.

carat, unit of weight for diamonds and certain other precious gems. Before 1913 the weight of a carat varied in different gem centres.

Carat measures weight, not size. A carat is a standard milligram measurement of weight, recognized and used globally.

Carat denotes the weight of a diamond, not the size. A diamond may have a higher carat weight without appearing larger; and two diamonds of the same carat weight can vary in size if one is cut deeper …

A carat is a unit of weight used to measure gemstones and pearls. One carat equals 200 milligrams or 0.2 grams. The heavier the stone, the higher its carat weight. Important note: Carat weight is not the …

Aug 4, 2025 · A carat is a unit of mass and weight used to measure gemstones and pearls, most notably diamonds. One carat is precisely equivalent to 200 milligrams (.2 grams).

Jun 18, 2025 · Curious about the average carat size for a diamond engagement ring? Here, an expert shares just that—and explains how this number varies based on where you live and your age. Plus, …

Not sure the size of a particular diamond based on its carat weight? Our helpful guide breaks down diamond sizes by diamond shape and millimeter (mm) size.