Carat or Karat is how you measure the purity of gold. The purity can go up to 24 units meaning the gold alloy is 99.9% pure. 14 carat means that 14 parts gold and 10 parts another metal. “K” is used to indicate carat content of the gold.
Most Arab countries prefer 24 carat gold while in India, where the measurement was later developed, and Southeast Asian countries it is 18 to 22 carat that is mostly used measurement. Most European countries and the United States it vary between 10 and 18 carat while 14 carat being the most popular in U.S. because it represent right balance of metals and color. The color of gold varies due to the mixing of gold and other metals. Yellow is the most common color but pink, white (due to use of nickel or palladium) and variety of other colors are also available.
Pure gold is very soft and very fragile; therefore, not used in making jewelry. Different metals such as copper and silver have been used to strengthen gold.
Jewelry manufacturers stamp the gold content on the finish product. When you purchase a piece of gold jewelry make sure to look for this stamp.