There are currently a lot of fake silver coins making the rounds on Craigslist and Ebay. Most risky buys are uncirculated U.S. silver dollars (circulated are OK) and 1 oz silver bullion rounds. If buying used, it is best to buy from a seller with uniformly positive feedback and to pay with a credit card so that the transaction can be reversed directly. If buying new, there is no reason not to go straight to APMEX or a similar mint and purchase silver rounds from them. If you join their mailing list and wait for specials, you can get rounds for as cheap as $0.99 over the spot price of silver.
If you have bought something that you are suspicious of, here are all the tests I know of that you can use to make up your mind to send it back or not.
- Compare the size and weight of the coin to a known silver coin. Be sure to examine the thickness too.
- Flip the coin in the air and compare the sound to that of a silver dollar or silver eagle. Alternatively, balance the coin on the end of a finger and tap it with another coin, allowing it to vibrate. Silver will resonate sweetly for several seconds.
- Use a strong magnet to check if the coin is at all magnetic. If it is, it is not 100% silver.
- Use a magnifying glass and compare the surface with that of a known silver coin. It should not look “soapy” or have a different sheen to it. Also look for imperfections where a plated metal might be showing through, especially around the edges.
- Use a digital caliper to measure the dimensions of the coin, find volume, and multiply by density to arrive at presumed weight. Use the same method on a known silver coin to arrive at its presumed weight. Then measure the weight of the silver coin and that of the suspect coin. If the proportional difference between presumed and measured weight of the suspect coin is different than that of the silver coin, there may be something wrong with it.
- Use a balance to measure the weight of the coin in air, then use string to suspend the coin into water and measure its weight. Subtract the water weight from the air weight, and divide the difference into the air weight, then multiply by 100. This is the specific gravity. Compare this to a chart of specific gravities to see if it compares to silver.
- Use an acid test kit to test the coin. (Can be obtained for about $20.)
- Use a sonic resonance tester to test the coin. (Expensive, but a coin shop or jeweler can do it for you.)
- Cut into the coin or grind an edge to see if the metal on the inside matches the metal on the outside. (But, obviously, only do this if you know you’re stuck with it and just have to satisfy your curiosity.)
Here are some external sites that may prove useful:
- Silver-coins.org with information on numismatic fakes
- Are My Gold And Silver Coins Counterfeit?
- Guide about fake silver rounds on Ebay
- Description of ring test on Ebay
- Description of fake one troy pound rounds and how to conduct specific gravity test
- More info on fake one troy pound Morgan and other rounds