How to Spot Fake Gold and Silver Coins and Bars

Fake gold and silver are a real problem, but they are also avoidable. Most fakes reach people through private sales and cheap online listings, not through established dealers that stand behind what they sell.

This page covers where fakes turn up, the simple checks you can do at home, what those checks can't prove, and when it is worth paying for a proper test. The short version: weigh it, measure it, compare it with the mint's own numbers, and let a professional test anything valuable.

Where do fake gold and silver coins come from?

Mostly from sellers you can't hold to account: classified ads, online marketplaces, social media and strangers. The US Mint tells buyers to use caution with "classified pages, online forums, and other sources," and to take extra care with any coin offered below the market price.

Below-market pricing is the biggest tell. Real gold is easy to sell to a dealer for close to spot (the market price of an ounce of metal right now), so few honest sellers would take much less. If a deal looks too good, assume the metal is the problem.

Common fakes include:

• Silver coins with a core of cheaper metal and a thin silver coat on the outside.
• Gold coins and bars with a tungsten core under real gold. Tungsten is used because it weighs almost the same as gold.
• Replica coins sold as souvenirs or props, sometimes resold later as real.

How can I tell if a gold or silver coin is real at home?

Weigh it and measure it. The Anti-Counterfeiting Educational Foundation, a nonprofit that studies fake coins, calls weight and diameter checks "the most cost-effective and reliable way" to catch most fakes. A digital scale that reads to a hundredth of a gram and a digital caliper are inexpensive.

Then compare your numbers with the mint's published specifications. The US Mint lists these for its bullion coins:

The Gold Eagle weighs more than an ounce because it is 22 karat gold. It holds one full troy ounce of gold (a troy ounce is about 31.1 grams), plus a little silver and copper for hardness.

Other mints and refiners publish the same kind of numbers for their coins and bars. A coin that is off on weight or size is not genuine. The Mint's checklist also asks whether all of the coin's design features are present, and whether the coin is certified by a third party or backed by the seller in writing for weight and metal content.

Are gold coins magnetic?

No. Gold and silver are not attracted to a magnet, so a coin or bar that sticks is not what it claims to be. That makes a magnet a quick way to catch the crudest fakes, which use iron or steel inside.

But passing proves very little. The Anti-Counterfeiting Educational Foundation says today's fakes use cores that a magnet doesn't pull, such as lead, titanium, copper or brass. Most fake silver coins it has cut open had centers of lead or copper.

Some people also tap a coin and listen for a long, clear ring. It takes practice to hear the difference, and it doesn't tell you what is inside. Treat it, like the magnet, as a first screen, not proof.

How do you spot a fake gold bar?

The same way, with one big limit. Weigh the bar and measure its length, width and thickness against the refiner's published size. A bar that is too light or the wrong size is fake.

The limit is tungsten. PubChem, the National Library of Medicine's chemistry database, lists gold's density at about 19.28 grams per cubic centimeter and tungsten's at about 19.3. Because they are nearly the same, a well-made bar with a tungsten core and real gold outside can pass a scale and a ruler. Counterfeiters of gold coins prefer tungsten for this reason, the foundation says.

An assay card or serial number is the refiner's statement of what the bar should be. It helps when you sell, but it is printed paper and plastic, not a test of the metal in your hand. For larger bars, a professional test is worth the cost.

Do vinegar, toothpaste or bleach tests work?

None of them is reliable proof. Fakes are usually coated with real gold or silver on the outside, so a coin can pass a kitchen test and still have a lead or tungsten core.

Some tests can also hurt a real coin. The foundation warns that acid testing can damage a genuine coin's surface and make it less desirable, especially to collectors. The same care applies to scratching or rubbing a coin. If you want to know, pay for a professional test instead.

What does a COPY mark mean?

It means the coin is a replica. Under the Hobby Protection Act rules from the FTC, an imitation coin made in or imported into the US "shall be plainly and permanently marked" COPY. The word must be in capital letters on the front or back of the item, not on the edge.

If you see COPY, it is not real gold or silver, whatever the listing says. If you don't see it, that proves nothing. People making fakes to cheat buyers don't follow the marking law.

When should I pay a dealer or assay office to test it?

Whenever the amount is more than you could comfortably lose, and always for a bar or coin bought privately. Many coin shops and bullion dealers can test a piece, and most test anything they buy. Ask about the cost first. Assay offices and refiners (companies that melt and certify metal) do more thorough testing for a fee.

Testing methods differ. Some machines read the metal's makeup without harming it, and others look at how the whole piece behaves. Ask what method they use and whether it checks only the surface or the inside of the piece. For a large bar, a melt test is the final word, but it destroys the bar, so it usually only makes sense when selling to a refiner.

What else should I know before buying?

Even real metal has limits. Gold and silver pay no income, cost money to buy, sell, store and insure, and their prices can swing or stay flat for years. A fake simply adds one more way to lose.

If you are new to this, our 10 red flags of gold and silver scams cover the other common traps, and coins vs. bars explains which pieces are easiest to sell later. When you do sell, any reputable buyer will test the metal first, which is one more reason to buy only what you can check.