How to avoid buying fake coins.
It isn’t actually that easy to fake a gold coin so at the moment they are relatively rare. One trick is to take make a gold coin and then artificially age it to try to fake a rare gold coin. This should be spotted by an expert though.
If you are worried, there are a few simple ways of testing that a gold coin is the genuine article.
The first and easiest way to check a gold coin is genuine is by its weight. Gold is a very heavy metal and if the gold has been mixed with other metals then the coin will weigh less than it should. There are only two metals that come close to the weight of gold. The first is platinum which is very expensive so there would be no advantage to swapping it with Gold. The second is tungsten which is too brittle to use in fake coins. If you buy some scales which are accurate to 1/100g then you can weigh the gold coin to check its weight. You can get a list of all the correct weights of gold coins on the internet.
The second thing to check is size. The width or diameter of real gold coins are available online. If your gold coin has other metals mixed with the gold it might be thicker than it should be.
Another way to check the weight and size of a gold coin is to buy a specialist tool such as the Fisch. This tool checks gold coins based on their weight, diameter, thickness and shape. Coins have to meet all four criteria to pass. A cheaper method is the ‘Gold Coin Balance’. To put it simply, if the balance tips, the weight is wrong and the coin is a fake.
One thing you should always do is to buy your gold coins from a dealer you trust. Do your research before you buy ! If you are buying in the UK have a look at the London Mint Office. Another option for the UK and many other countries is Gold Direct.