18k
eight·teen kar·at | ˈāt-ˈtēn ker-ət
adjective
A gold alloy that includes 75% pure gold and 25% alloy
18k alludes to the amount of pure gold in any given piece. Gold is an extremely soft metal that must often be mixed with an alloy to make it more durable. In numerical terms, 18k gold is 75% gold and 25% alloy. The number 18 refers to parts of 24, or karats. 18k gold is the alloy with the highest amount of gold content sold in most rings, and its color is closer to that of pure gold. Due to the metal’s higher value and slightly lower durability, 18k gold is used primarily in the high-end jewelry industry. In addition, it is reasonably pure but is not overly soft. Karat standards may possibly vary from country to country. For instance, in some areas of Europe, the minimum standard is 1BK, while in others, the minimum is 9K.