Karat
/KAIR-ut/
Definition
A unit of measurement indicating the purity of gold in an alloy, expressed on a scale of 24. Pure gold is 24 karat (24k); 18k gold is 75% pure gold.
Karat (abbreviated 'k' or 'kt,' not to be confused with 'carat' which measures gemstone weight) indicates the proportion of pure gold in a metal alloy. The scale is based on 24 parts: 24k = 99.9% gold, 22k = 91.7%, 18k = 75%, 14k = 58.3%, 10k = 41.7%, and 9k = 37.5%. Higher karat gold is more yellow, softer, and more expensive per gram. Lower karat gold is harder, more durable, and available in a wider range of colors (white, rose) because the non-gold metals in the alloy can be varied. The jewelry trade primarily works with 14k and 18k gold — 14k dominates the US market for its durability and affordability, while 18k is preferred in Europe and Asia for its richer color and prestige.
Usage in the Trade
Karat is used by jewelers, consumers, and appraisers to describe and evaluate gold jewelry. It appears on hallmarks and stamps inside rings, on clasps, and on jewelry tags.