How to Spot a Counterfeit Half Eagle Gold Coin

Weigh the coin with a very sensitive coin scale. All Half Eagle gold coins weigh 8.3 g. Even a worn Half Eagle will not vary in weight more than 0.1 g. According to BullionGoldCoins.com, counterfeit Half Eagles weigh significantly less because they are made with metals other than gold. A fake Half Eagle made out of brass or a copper alloy will weigh only about 4.6 g.

Feel around the edge. Most counterfeit Half Eagles are made with molds made from genuine coins. The molten metal for these counterfeit coins is poured into the mold along a hole in the edge. You can often feel a small bump along the edge where the metal was poured in. You might also feel a flat spot along the edge where the counterfeiter sanded off the bump. If the edge of a Half Eagle does not feel uniformly round, it could be counterfeit.

Compare the surfaces of the Half Eagle to a coin you know is authentic. Counterfeit Half Eagles will lack sharp detail. Counterfeits are often crooked, bumpy or show cracks. Some appear too shiny and feel slippery to the touch. All these imperfections are the result of making an imperfect mold from an authentic coin and using metals other than gold.

Peer through a magnifying glass or microscope to examine the mint mark. A mint mark is a small letter signifying the mint where the coin was made. They are on some, but not all, U.S. coins. On the Half Eagle gold coin the mint mark is either near the date or on the reverse to the left of the arrows. One of the great rarities of the series is the 1909-O Half Eagle. The "O" signifies that the coin was made at the New Orleans Mint. According to CoinQuest.com, this coin is worth more than $3,000 as of 2010. Forgers often scratch an "O" onto a 1909 Half Eagle that doesn't have a mint mark. If the mint mark appears scratched instead of stamped into the coin, it is probably counterfeit.

Note if you appear to have a 1929 Half Eagle gold coin and be especially skeptical, because this is one of the most commonly counterfeited coins in the series. According to CoinQuest.com, this coin is worth more than $7,000. It is a good idea to have any 1929 Half Eagle verified by a professional coin grader before buying or selling it.