The Magnet Test All you have to do is find a magnet and put the gold coin against it to see if it attracts the gold coin. Since a pure gold coin has no metal other than gold, the magnet will show no attraction. If it is a fake, the gold coin will stick to the magnet due to the presence of metal.
Because of the density of Gold with 19.32 g/ml, it is heavier than other metals. So, if you wish to check the purity of a gold coin, simply put it in water. If it is made of pure gold, the coin will hover over the button or completely sink, whereas, in the case of any other metal, the coin will simply float.
The most trustworthy method to test if something is gold plated or solid gold is to have an acid test done it. For the acid test, take a small piece of jewelry, or using a small needle scratch a tiny part in your gold, take a dropper given in the acid kit, fill it with acid.
Perform a Magnet Test
Gold is a precious metal not susceptible to magnetic forces. Thus coins containing a high concentration of gold will not react during a magnet test. This test is an easy way to detect counterfeit gold coins since they often have inexpensive metals that are magnetised.
Apply a few drops of white vinegar to your gold jewelry. Real gold will not change color, but vinegar can cause fake gold items to react and change color.
(Fun fact: Real gold is not magnetic.) Fake gold, on the other hand, will stick to the magnet.
What Kind of Metals Are Not Magnetic? In their pure, natural forms, gold, silver, aluminum, copper, brass, and lead are not magnetic. This is because they are all weak metals.
Each Australian Gold Coin is struck in 99.99% pure gold and individually packaged in hard plastic capsules at the Perth Mint.
In a nitric acid test, a jeweler places a few drops of the acid on the piece and watches the reaction. With copper, the reaction usually causes the liquid to turn green, give off fumes, and sometimes bubble. This response is known as a hard cupric reaction and indicates that your piece is not real gold.
Goldmeter - real gold detector on the App Store.
Acid test.
An acid test can reveal the karat of solid gold jewelry, but it can also show whether jewelry is solid gold or gold-plated. With an acid test, a small sample of the jewelry is removed and exposed to acid to induce a color change. The resulting colors indicate which type of metal the jewelry is made of.
The best way to protect your gold coins or bars is to not handle them unless it's necessary, but sometimes you might want or need to. Gold is delicate, so to prevent your bullion from being damaged by a hard surface when handling it, place it on a clean towel or cloth on a flat surface.
The 1920 Sydney Mint Sovereign is legendary. It is Australia's rarest sovereign with only three circulating examples privately held.
There is only one coin with a truly good weight-to-value ratio and that is the $2 coin. Finding a $2 coin still means something. To illustrate this, a kilogram of $2 coins is worth $303, while a kilogram of 5c pieces, 10c pieces or 20c pieces is worth $17.60. Finding a $1 or $2 gold coin still means something.
Apply acid to the metal.
Apply concentrated acid to the metal. Brass will react with acids and gold will not. If you see bubbling or discoloration where the acid is applied, your piece is brass. If there is no change after applying the acid, you have gold.
The most common mineral mistaken for gold is pyrite. Chalcopyrite may also appear gold-like, and weathered mica can mimic gold as well. Compared to actual gold, these minerals will flake, powder, or crumble when poked with a metal point, whereas gold will gouge or indent like soft lead.
Neodymium magnets are very strong and can help to test the authenticity of gold and silver bars, coins, bullion, or jewelry.
Neodymium rare earth magnets for testing gold and silver purity.
The Magnet Test
Since gold is not a magnetic metal, your jewelry should remain unaffected. If it sticks to the magnet, it's fake. (This test also works with silver, another non-magnetic precious metal.)