Answer:
First off, grab a simple magnet and hold it near your precious metal coin. If the coin is even slightly attracted to the magnet, then you know you have a fake on your hand, as metals with contents of iron and steel are the most likely to be attracted
A magnet will tell the difference if the coin is fake or not because is a coin is real it will stick and be magnetised to the magnet. If the coin is fake it will not stick, it will not magnetise, it means thay its fake.
