The karat system is used to reveal the amount of pure gold found in an item. Since pure gold is too soft to withstand the stresses of every-day wear, it is alloyed with a mixture of metals like silver, copper, nickel, and zinc to give it strength and durability. Products made from gold are marked to show how much actual gold is contained in the product:
 

• 24 karat = 100% gold
• 22 karat = 91.7% gold
• 18 karat = 75.0% gold
• 14 karat = 58.3% gold
• 10 karat = 41.7% gold