How to authenticate a coin? There are a number of factors to consider when authenticating a coin. First, look to see if the coin was struck in the right metal. If the coin is struck in a base metal and should be silver or gold, it is a replica or counterfeit. You may also want to check the rim of the coin. If there appears to be a seam, the coin is an electroplated replica. Weight is often the best giveaway. Most coins have specific weights, and if the coin does not match that weight, it is most likely a replica.
Should a coin be cleaned? PLEASE DO NOT CLEAN YOUR COINS! Just like any antique piece of furniture or painting, the original surface of a coin is much more desirable to collectors than altered or damaged surface. As a result, cleaned coins are worth significantly less than wholly original coins. Even though a coin is dark in color, it does not mean that it is less valuable. The metal in coins often oxidize and produce a wide array of colors called toning. Some collectors hunt for wholly original coins with this type of toning.