If you’re collecting gold coins or investing in them, there is a good chance that sooner or later you will be introduced to a dubious specimen that you would wonder about whether it’s a real thing or a counterfeit. It’s not easy at all to recognize fake gold coins and you may not spot them at first (and probably even at last either), but you should know at least a few things that may help you not to fall into a trap.
The oldest way to check if the coin is real was simply biting it – please note, I don’t recommend doing it, but rather just mention it. You must have seen it in movies about old times, treasure hunters, and pirates. It may seem odd but in fact, there is a very rational explanation for it. Gold is very soft metal, comparing to some base metals, such as copper or bronze for example, and biting a real gold coin would leave some teeth marks or at least leave a feeling that it’s biteable. Again, I would not advise testing fake gold coins this way for two reasons: if it’s a fake, you may break your teeth, and if it’s a real thing, you may ruin it by biting (and possibly break your teeth anyway).
Another way to check if the coin is a fake is to listen how it jangles. Fake gold coins sound dull and boring according to people who have very good ears. Again, this test may rather be not always reliable and you would have to spend years listening to real and fake gold coins to learn how to tell them apart.
Nevertheless, jokes aside, the most reliable way to check if your coin is real, is to ask a professional. Get you coin to your local coin dealer and most likely he or she will have enough experience and appropriate equipment to check if your treasure is genuine. There’re several devices developed for this purposes, but they may be quite expensive, hence not always accessible or affordable for general public fiddling with gold coins.
There’re a few things again that you can try even if you have no access to or desire to communicate with your local coin dealer:
Check for the coin details. If you don’t have a real coin to compare with, find a photo online and compare very little detail of the original with the one you’re checking. Look at the space between letters, look at the size and number of elements – it may sound stupid, but counterfeiters do miss such simple things for some reason and they even do grammar mistake, especially when then do it in foreign languages, so check spelling as well.
Find a coin forum (CoinForum for example), become a member, and ask there – there’re plenty of real experts and they will help you or at least will give you some pointers. You can usually attach a link to a web page or put a photo of the coin in question.
Check the coin weight and size. If you don’t have a coin catalogue, you can almost always find these details online. Fake gold coins are usually lighter and sometimes even smaller in diameter.
Check the coin rim (edge). Fake gold coins sometimes are made in halves and then soldered or glued together and sometimes you can see a very thin (or not very thin) seam on the rim of a fake coin.
Dare your seller to make an “acid test” – gold is a noble metal so it will not react or dissolve in nitric or sulphur acid. Hmm, this one is a bit too extreme as if your coin is not 99.9% fine gold, which is quite common for real gold coins, the test will still damage the coin, so this one is for your information only.
Be very careful whom you’re buying from. Buying online is fine, but see where your seller is, check his or her feedback, and check that this feedback is for selling gold coins, not for buying 5c post cards.