What is a Carat?

Measures the purity of gold, and is the British spelling of “Karat”. In Britain, Carat is used both for the measurement of gold and for the measurement of precious stone. However, in the U.S., it is generally only used for measuring precious gems.

Generally, substituting karat for carat when measuring precious gems is considered inaccurate. However, substituting carat for karat when measuring the purity of gold is acceptable. While it is acceptable to use “K” to signify karat in measurement, carat must always be spelled out.

Outside of Britain, carat gold is used in South Asian and South Africa. The word carat comes from the Greek word keration which signifies a small weight, or carob bean. Historically, traders in and around the Mediterranean used carob beans as a way to measure jewelry. The traders believed that the beans were fairly consistent in size and weight and therefore relied on them as a unit of measurement.

The weight of a carat is set at 1/24th parts pure gold in an alloy. If a pair of earrings had 1 4 parts gold and 10 parts of another metal such as copper, those earrings would be 14-carat gold. Since gold is such a soft precious metal, jewelry is very rarely 100% gold. Even in “pure” 24-carat gold pieces, the composition is generally at 99.9% gold.

In the United States, carat refers to the measurement of precious stones. Therefore in the U.S., you can have a piece of jewelry that uses both the measurement of carat and karat. As a unit of measurement, one carat is equaled to 200 milligrams.

Before standardization counties had their own carat measurement for gemstones and pearls. The International carat was proposed by the International Committee of Weights and Measures and accepted at the Conference of the Metric Convention in 1907.

See Also…

Karat, Fineness, Bullion Coin, Alloy

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