Real or fake? Simple checks for gold and silver coins and bars

Gold and silver are valuable, so they get counterfeited. In the past, a fake could often be spotted from a distance. These days there are counterfeit coins and bars that look very real at first glance. Fortunately, you don’t need a laboratory to expose most fakes. A few simple checks will get you a long way.

One rule before you start: don’t use an acid test and never scratch a coin or bar you want to keep. An acid test or a scratch on a touchstone leaves marks and lowers the value. All the checks below are non-destructive.

1. Weigh it

The simplest test, and one of the best. Gold and silver are heavy, and a counterfeiter can’t easily get both the right weight and the right dimensions at the same time.

Use digital scales accurate to 0.01 grams and compare the result with the official specifications:

Coin	Weight	Diameter	Fineness
Krugerrand 1 oz (gold)	33.93 g	32.77 mm	916.7
Maple Leaf 1 oz (gold)	31.11 g	30 mm	999.9
Maple Leaf 1 oz (silver)	31.11 g	38 mm	999.9

The Krugerrand weighs more than 1 ounce because it contains copper. Its gold content is exactly 1 troy ounce. You can read more about this in Fine weight, fineness and karat.

If the weight is clearly off, there is reason for suspicion. A difference of a few hundredths of a gram can come from wear or the scales. A difference of half a gram or more on a 1 ounce coin is a serious warning sign.

2. Measure it

A clever counterfeiter makes a coin from a lighter metal and then makes it slightly thicker or larger so the weight is right. With callipers you can see this. Measure the diameter and the thickness and compare them with the official dimensions, or with a coin you know for certain is genuine.

For bars, measure the length, width and thickness. A tungsten bar with a layer of gold is a well-known fake. It is hard to detect by weight, but sometimes the dimensions give it away.

3. Use a magnet

Gold and silver are not magnetic. If a coin or bar is attracted to a strong neodymium magnet, it contains iron, nickel or steel and is definitely not genuine.

But be careful: not magnetic proves nothing. Copper, lead, zinc and many alloys are not magnetic either. And tungsten, the counterfeiter’s favourite metal, is not magnetic and has almost the same density as gold. So the magnet test only rules out the crudest fakes.

4. Listen: the ring test

Real silver gives a clear, long-lasting ring when you tap it gently. You can balance a coin on your fingertip and tap it lightly with another coin. A fake made from a different metal sounds duller and shorter.

There are also apps that analyse the sound through your phone’s microphone and compare it with the sound of genuine coins. This works best with well-known bullion coins, and you can’t test a coin in a capsule this way.

Tip: Type the name of a well-known coin into AgAurium and the shared catalogue fills in the official weight and dimensions. Put your own measurement next to it and you will see straight away if anything is off. Try AgAurium for free →

5. The ice test for silver

Silver conducts heat extremely well, better than almost any other metal. Put an ice cube on a silver coin or bar and it melts remarkably quickly, as if it were on a hotplate. On a fake made from another metal, this happens noticeably more slowly. If you can, compare it with a genuine piece of silver of roughly the same size. Copper also conducts heat well, so this test is mainly a quick first impression.

6. Work out the density

If you want to be more precise, determine the density using the water displacement method:

1. Weigh the coin or bar normally (weight in air).
2. Hang it on a thin thread in a glass of water standing on the scales, without touching the bottom or the sides. The increase on the scales is the weight of the displaced water.
3. Divide the weight in air by that increase. That is the density in g/cm³.

Compare with the known values: pure gold is 19.3 g/cm³ and pure silver 10.5 g/cm³. Alloys such as 22 karat gold or sterling silver come out slightly lower. With small coins the method is less accurate, because a small measuring error then makes a big difference.

Note: this test doesn’t reliably detect a tungsten core either, because tungsten (about 19.25 g/cm³) is almost as heavy as gold. The dimensions and an electronic test help more there.

7. Have it tested by a dealer

For more certainty, there are devices most private collectors don’t own:

• Electronic testers measure how well a coin or bar conducts electricity, including some way below the surface. This also exposes gold-plated tungsten and other core fakes.
• XRF machines measure exactly which metals are present at the surface. This is accurate, but a thick layer of real gold over a different core can make the surface look genuine.

Many coin dealers can test an item for you. You can read more about tools in Tools for collectors.

Prevention is better: buy wisely

The best protection isn’t testing but buying well.

• Be wary of a price that’s too good. Gold and silver have a worldwide spot price. Anyone selling far below it usually has a reason.
• Buy from established dealers with a fixed address, a good reputation and clear terms. Be extra careful with private sellers on marketplaces and with offers via social media.
• Check certificates and serial numbers on bars. The number on the bar must match the number on the certificate. Some manufacturers offer an online check.
• Check graded slabs online. Slabs are counterfeited too. Look up the certificate number with the grading service and see whether the description and any photos match your coin.
• Keep the original packaging. A bar in an unopened seal with its certificate is easier to verify and to sell.

Unsure about a purchase? Ask for photos of the front and back, the weight and the dimensions first, and compare them with the official figures before you pay.

How AgAurium helps

Testing is most useful when you know what you are comparing against. In AgAurium, the shared catalogue fills in the official weight and dimensions of well-known coins and bars as soon as you type the name. Put your own measurement next to it and you will see straight away if anything is off.

For bars you record the serial number, and you keep the certificate or invoice with it as proof of purchase, as a PDF or photo. These details are visible only to you. That way you have everything together when you sell or have doubts, even if the paper certificate ever goes missing.

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