Carat - The weight
Carat is an ancient inherited unit of weight in which gemstones are measured. The word "carat" traces back to the seed of the carob tree, which was used as the unit of measurement for diamonds in the past. Its grains have a constant average weight of 0.2 grams. Even today, we refer to "carat" as a unit of weight. It should not be confused with the German word "karat," which is spelled with a "K." In this context, for example, 18 karat refers to 750 gold. It is important to consider the carat weight of a diamond together with its cut. If the diamond's cut is poorly executed, even a high carat weight will appear dull. Diamond prices are always indicated as p.ct (per carat).
Size chart for carat weight
The size of a 1-carat diamond can vary slightly depending on how the stone is cut, even when the diamond shape is the same. Larger rough diamonds are rarer than smaller diamond crystals, which is why the prices per carat do not increase proportionally. The illustration is meant to give you a sense of the relationship between carat weight and the diameter of a brilliant-cut diamond. However, please note that the illustrations are not to scale.