Things You'll Need
Instructions
Search the faces of the coin for a declaration of the amount of precious metal in the coin. On the popular silver American Eagle bullion coin this declaration is on the reverse and it read "1 oz. fine silver." All genuine U.S. bullion coins have this information somewhere on one of the coin's faces.
Examine the certificate of authenticity, if one exists. All U.S. bullion coins initially come with certificate of authenticity. This certificate can be counterfeited or lost, so the presence of a certificate of authenticity isn't a definite indicator of a coin's legitimacy, but it can certainly help to alleviate any initial fears on your part.
Find the coin in an up-to-date U.S. coin price guide. If the coin does not exist in the price guide, it is a fake. You can also search the U.S. Mint's website in order to find out more information about specific U.S. bullion coins.
Weigh the coin, if at all possible. Your price guide can give you the specific weights of U.S. bullion coins. If the weight of the coin is off by more than an extremely small margin, the coin is likely to be a fake.
Take the coin to a dealer if you have it in your possession and you still can't determine its authenticity. A dealer can tell you if the coin is genuine or not.