Unlike most metals, gold is not magnetic and a genuine gold investment coin, bar or piece of jewelry does not stick to a magnet. You can try this at home using any reasonably strong magnet. Try picking up your gold coin with a magnet. This is because 24-carat gold consists exclusively of gold, whereas other types of gold contain other metals.
careful though, as some pieces of gold may have a false stamp engraved to pass them off as pure gold. Gold doesn’t rust either. So when you see signs of rust, you know that your piece isn’t real gold and you don’t have to worry about damaging your item if it is actually real gold. If it shows any signs, you must be aware that it is not real gold, but fake gold, which contains only limited gold on the surface of the product. Coins such as the 22-carat American Gold Eagle and the Gold Krugerrand weigh more than a troy ounce because they are made from alloys.
If the black strip doesn’t appear, it’s a sign that your gold is counterfeit or is likely made of another metal or is gold-plated. This test isn’t absolutely foolproof, as some metals that aren’t gold are also heavy, so they sink and make you believe they’re gold. The gold nitric acid test is one of the riskiest tests because you can damage your gold if it is mixed with other metals. If your gold coin doesn’t do anything, that’s another sign that your gold coin is pure and you’re not dealing with a counterfeit.
If you drop gold into a glass of water, it is immediately not real gold when it floats and starts to discolor.