Karat (k) is used for gold, carat (c) for gemstones.24k indicates pure gold, 100% gold percent by weight. 18k indicates 18 karat gold, or by weight 18 parts gold to 6 parts other metals, or 75% pure gold.14k indicates 14 karat gold, or by weight 14 parts gold to 10 parts other metals, or 58.33% pure gold.10k indicates 10 karat gold, or by weight 10 parts gold to 14 parts other metals, or 41.7% pure gold and the minimum amount of gold in a product that can be called gold in the USA.Other metals added are usually copper, nickel palladium, or silver to add strength to gold which of itself is too soft to endure as jewelry or electronic components
