Every collector should know all the basic glossary terms when ever collecting coins, so that they will have a much better understanding when they are purchasing from private coin dealers, due to so many individuals becoming first time collectors a glossary of terms has been composited just for you. An alloy is a mixture or two or more metals combined together to create one, which sometimes can be a less expense metal mixed with a much more valuable one. The American Eagle Bullion Coins are platinum, silver, and gold coins that were released by the United States Mint beginning back in October of 1986.