Gold is an incredibly durable metal, but it's too soft to be used by itself in jewelry, so it's alloyed (mixed) with other metals to give it more strength. The amount of fine metal in an alloy is measured in karats. Twenty-four karat gold is considered virtually 100% pure; 14k gold contains 14 parts pure gold and 10 parts other metal alloys. Fourteen-karat gold is the most commonly used gold for jewelry – it's valued for its rich luster, bright color, durability, and affordability. Highly scratch-resistant, it's ideal for everyday wear.