What is the difference between 14c and 18c gold?

14K gold is an alloy that is made up of 58.3% pure gold and 41.7% other metals, while 18K gold is an alloy that is made up of 75% pure gold and 25% other metals. The higher the percentage of pure gold in the alloy, the more valuable and more expensive the gold will be. 14K gold is less expensive than 18K gold because it contains less pure gold and more other metals, which makes it less valuable.