Compare the coin or bar with its official weight, diameter and thickness, look closely at the details, and check that it isn't magnetic. A piece that fails any of these is a red flag, but passing them doesn't prove it's real, so have anything doubtful tested by a dealer with an XRF machine or other professional tester.
Why fakes exist and who they fool
Gold coins and bars are worth a lot for their size, so people make copies. Some are honest souvenirs. Others are made to fool buyers. Fakes often turn up in inherited collections, online marketplaces and private sales, where nobody checked the pieces when they were bought.
If you’re selling, a fake won’t get you paid, so it helps to know before you visit a buyer. If you’re unsure about a piece, these checks help you decide whether to get it tested.
Know the real specs first
Every government bullion coin has published specs: weight, diameter, thickness and purity. Look up your coin on our coins page. Each page shows the official weight and diameter. For a branded bar, check the maker’s own listing for that size.
The checks below compare your piece against those numbers.
Check 1: Weight
Weigh the piece on a digital scale that reads to at least 0.01 gram. A pocket jewelry scale works. See scales on our tools page and how to weigh gold at home.
Real coins from a mint are made to tight limits. A coin that’s clearly too light or too heavy is a warning sign. Remember that 22K coins, such as the American Gold Eagle, weigh more than their gold content, so compare against the coin’s total weight, not “1 ounce”.
Check 2: Size and thickness
Measure the diameter and thickness with calipers. See calipers on our tools page.
This check catches a common trick. A fake made of a cheaper, lighter metal can be made to weigh the right amount, but then it has to be thicker or wider than the real coin. A piece with the right weight but the wrong size is a strong red flag.
The hardest fakes use tungsten, a metal almost as heavy as gold, covered in a gold layer. These can pass weight and size checks, which is why professional testing matters for valuable pieces.
Check 3: The magnet test
Gold isn’t magnetic. Hold a strong magnet near the piece. See magnets on our tools page.
- If it sticks or pulls toward the magnet, it isn’t solid gold.
- If it doesn’t react, that’s a good sign, but it doesn’t prove anything. Many fake metals, including copper, brass and tungsten, aren’t magnetic either.
Check 4: Look closely at the details
Use a magnifier (a jeweler’s loupe works well, see loupes on our tools page) and compare your piece with clear photos of a real one:
- Lettering and numbers should be sharp, evenly spaced and the same font as the real coin.
- The design should be crisp. Soft, mushy or blurry details are a warning sign.
- The edge should match the real coin. Many gold coins have a reeded edge (fine grooves around the rim).
- The color should look even. Worn spots showing a different color underneath suggest plating.
- Bars should show a maker’s name, weight, purity and often a serial number. Spelling mistakes, uneven stamping or missing details are red flags.
What the law says about replica coins
In the US, the Hobby Protection Act makes it unlawful to make or import a replica coin for sale unless it is plainly and permanently marked “COPY”. Under the FTC’s rules, the word must be in capital letters on the front or back of the piece, not the edge.
So if you find “COPY” stamped on a coin, it’s a replica with little or no gold value, unless the metal itself is marked and tested. Fakes made to deceive won’t carry the mark, so a missing “COPY” doesn’t make a coin real.
When to get a professional test
Home checks catch many fakes, but they can’t confirm a piece is real. Get it tested if:
- It failed any of the checks above.
- It’s valuable enough that a mistake would hurt, such as a 1 oz coin or a large bar.
- It came from an unknown source, or the price you paid seemed too good to be true.
Many coin dealers and gold buyers use XRF machines, which read the metals on the surface without damaging the piece. Some also use devices that check the metal under the surface. Ask what test they’ll use and whether it leaves a mark. See how gold buyers test your gold.
Avoid scratching or acid testing a coin yourself. It can damage the surface and lower any collector value. See how to test gold at home for safer options.
If you find a fake
Don’t try to sell it as real. If you bought it recently, contact the seller or the platform you bought it through about a refund, and keep any receipts and messages.
This is general information, not legal advice.
Last reviewed November 1, 2026. This guide is general information, not legal, tax or financial advice.