Karat vs. Carat: What Is the Difference?

Fine gold bar. Sashkin/Shutterstock

When you hear “carat” and “karat,” you may assume they are spelled differently but mean the same thing. However, the homonyms carat and karat refer to two separate forms of measurement, with carat referring to diamonds and precious gemstones and karat relating to how smiths measure the purity of gold.

Knowing the difference if you plan to buy or sell fine jewelry is essential. In particular, if you hope to find the perfect engagement ring for your special someone or add a diamond or piece of gold jewelry to your collection, you must familiarize yourself with these terms.

Carat vs. Karat: What Is a Karat?

Karat refers to gold purity, or gold in its purest form. Jewelers and goldsmiths measure the gold purity by the proportion of gold in a given piece of jewelry using a scale of 24 parts, or karats. Gold that is 24-karat is 100 percent pure gold because all 24 components in the mixture consist of pure gold. Jewelers also use karat to describe the parts of a gold alloy or the proportions of pure gold when combined with other metals, such as silver, platinum, or palladium.