The unit of measurement carat (or ct.) indicates the weight of gemstones and is one of the 4 C's of diamond quality characteristics. The term has its origin in Greek. The expression kerátion was used at that time for the horn-shaped fruits of the carob tree, where the seeds all weigh about 0.2 grams. Today's term carat originates from Latin (carratus) and was also transferred into the German language via French (carat). 1 ct. corresponds to 0.2 grammes. This value is also important for setting the price, as a heavy diamond, for example, is more expensive than a light one. However, the price does not increase in direct proportion to the weight, as larger stones are rarer and therefore cost more. The weight is also not a reliable indicator of size, as the measurements and proportions of the stones also matter. Two diamonds of the same weight can therefore differ in height and diameter. The type of cut is also central to the optical size, as a well-cut diamond appears larger than a less well-cut one.
