The short answer
Genuine gold coins are not magnetic. Gold is diamagnetic, which means it very weakly repels a magnetic field, and the effect is far too small to notice with a hand magnet. If a coin is strongly attracted to a magnet, it is not made of gold, or it contains a significant amount of iron, steel or nickel.
A coin that does not stick is not proven genuine, however. The magnet test only rules out some fakes.
Why gold is not magnetic
Magnetic attraction in everyday objects comes from ferromagnetic metals, mainly iron, nickel and cobalt, and their alloys. Gold, silver and copper are not in that group. All three are very weakly diamagnetic, so none of them will cling to a magnet.
Do alloyed gold coins stick?
Coins such as the American Gold Eagle, Krugerrand and British Sovereign are 22 karat, and the metals added to them are normally copper and silver. Neither is ferromagnetic, so these coins should not be attracted to a magnet either. See what gold coins are made of for how the alloys work.
A tiny trace of a magnetic metal in an alloy could in theory produce a faint response, but a genuine coin should not be pulled toward or stick to a magnet. If a coin from a mint known for gold coinage seems to react, treat that as a reason to investigate further, not as an instant verdict.
How to do the magnet test
- Use a strong neodymium (rare-earth) magnet. A weak fridge magnet is not sensitive enough.
- Make sure the coin is clean, dry and out of its capsule if the capsule contains any metal parts.
- Hold the magnet near the coin, then touch it to the coin’s face and edge.
- Note whether the coin is pulled toward the magnet or sticks.
Keep strong magnets away from electronics, credit cards and your fingers, because they can pinch.
The slide test
A slightly more sensitive version is the slide test. Place a neodymium magnet on a gentle incline and slide the coin down it. A non-magnetic coin should slide down smoothly. Copper, silver and gold coins are all conductors, so they can move more slowly down the magnet due to induced currents, so the slow slide is not a sign of a problem and does not by itself identify the metal. A coin that stops, sticks or is clearly pulled is the red flag. Because the effect depends on the coin’s thickness and metal, compare your coin against a known genuine coin of the same type when you can.
What the result means
- It sticks strongly: the coin is almost certainly not gold. Steel, iron and nickel-based fakes are common and easy to detect this way.
- It does not stick: the coin could be gold, but it could also be brass, copper, lead, silver or tungsten-cored, none of which are magnetic.
Fakes that pass the magnet test
Many counterfeits use non-magnetic metals. Brass and copper cores with gold plating will not react to a magnet, and tungsten, which has a density close to gold, is sometimes used to match the weight of a genuine coin. For that reason a magnet should be the first filter, not the last.
What to do next
After the magnet test, check weight, diameter and thickness against published specifications, inspect the design under magnification, and consider an electronic test or XRF analysis at a reputable dealer. Our guide on how to tell if a coin is real gold covers these steps in order.
FAQ
Do gold coins stick to magnets? Genuine gold coins do not.
Will a magnet pick up fake gold? It might, if the fake contains iron, steel or nickel. Fakes made from brass, copper, lead or tungsten will not be picked up.
What color does gold turn when it’s fake? A magnet will not change a coin’s color. Fake or plated gold can wear to reveal a different metal underneath, but chemical tests that cause a color change can damage a coin, so we do not recommend them on coins.
How can I tell if a gold coin is actually gold? Combine several checks, including weight, dimensions, density, magnet and professional testing, because no single test is conclusive.