Definition: Bullion is the pure form of a precious metal such as gold, silver, copper, or platinum, from which coin metal alloys are made. The U.S. Gold Eagle is not really pure bullion; it is an alloy of 91.67% gold, 3% silver, and 5.33% copper, although the total amount of gold content weighs out to a solid ounce. The U.S. Silver Eagle and the U.S. Gold American Buffalo are both considered to be true bullion coins, since their alloy is at least 99.9% pure.
U.S. coins made of bullion
are not intended for general circulation; they are made for the purpose of investing in precious metals.