Yellow Gold
You can find yellow gold in 14 karat, 18 karat and 24 karat. The purest form of gold is 24 karat, but you seldom see it in rings because it is too soft for setting a diamond; 14 karat and 18 karat are used most often.When we talk about 14 karat gold, we refer to an alloy (a mix of metals) of 14 parts gold and ten parts other metal. Eighteen karat gold is an alloy of 18 parts gold and six parts other metal, and so on. The more "other metal," the stronger the gold. White gold doesn’t exist in nature. It is an alloy of yellow gold and a mixture of nickel, palladium, rhodium, and other metals, which turns the yellow gold to white.