How to spot fake gold bars and coins
A fake gold bar or coin usually gives itself away through weight, dimensions or finish. The trickiest counterfeit, a tungsten core under a genuine gold layer, cannot be seen at home: tungsten is almost exactly as heavy as gold. That calls for a measurement that looks through the metal.
What kinds of fakes exist
- Gold-plated copper or brass – the most common. Lighter than gold, so at the right weight it is too large or too thick.
- Tungsten core – a block of tungsten with a layer of real gold around it. Tungsten has a density of 19.25 grams per cubic centimetre, gold 19.32: weight and dimensions are then almost right.
- Cast replicas – coins with blurred lettering, soft edges and the wrong milled edge. Some are even marked COPY.
- Real gold, wrong fineness – a coin or bar of lower carat posing as 999.9.
What you can check yourself
A precision scale (to 0.01 grams) and a calliper take you a long way:
- Step 1. Origin and papers. A bar from a known refinery has a serial number that matches its certificate. If it is missing, or the numbers differ, be careful.
- Step 2. Weight. Weigh to a hundredth of a gram and compare with the official figure. A gold Krugerrand weighs 33.93 grams, a Maple Leaf 31.1035 grams.
- Step 3. Dimensions. Measure diameter and thickness. The Krugerrand is 32.77 millimetres wide and 2.84 millimetres thick. A gold-plated copper coin of the correct weight is noticeably thicker or wider.
- Step 4. Magnet. Gold is not magnetic. If it sticks, it is fake. Tungsten is not magnetic either, so this step does not catch a tungsten core.
- Step 5. Finish. Compare lettering, milled edge and relief with a photograph of a genuine piece. Fakes are often less sharp.
A good result proves nothing conclusively. A tungsten fake can pass weight, dimensions and the magnet test. If in doubt, buy or sell nothing until it has been measured.
How a buyer measures it
For every bar and coin we buy, we measure the fineness by X-ray fluorescence (XRF). It reads the composition of the outer layer without damage. XRF cannot see a tungsten core under a thick gold layer, and neither can a density measurement, because tungsten is almost as heavy.
That is why, for bars from 100 grams upwards, we also carry out an ultrasonic or transmission measurement that reveals the inside of the bar.
How to protect yourself
If a piece turns out to be fake, we do not buy it and we tell you exactly what we measured. The measurement itself is free.
- Buy bars and coins only from a known dealer, and keep the certificate and receipt.
- Distrust a price below the market rate. Nobody sells real gold for less than the material is worth.
- Keep the packaging of a sealed bar intact; it makes the origin easier to establish when you sell.
- Bring the papers when you sell. We measure regardless, but the certificate helps.
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Questions about how to spot fake gold bars and coins
How do I spot a fake gold bar?
Check the serial number and certificate, weigh to a hundredth of a gram and measure the dimensions. A gold-plated copper bar is too large at the correct weight. A tungsten core can only be detected by an ultrasonic or transmission measurement.
How do I spot a counterfeit Krugerrand?
A genuine 1-ounce gold Krugerrand weighs 33.93 grams, is 32.77 millimetres wide and 2.84 millimetres thick. If any of the three is off, or the lettering and milled edge are blurred, suspicion is justified.
Why is tungsten used in fake gold bars?
Because tungsten, at 19.25 grams per cubic centimetre, is almost as heavy as gold at 19.32. A bar with a tungsten core therefore has practically the right weight and dimensions.
What do you do if a bar or coin turns out to be fake?
We do not buy it, and we tell you exactly what the measurement showed. The measurement itself is free.
Is your question not listed? Ask it below, call 085 060 3009 or go to contact.
Still something unclear?
Ask it here. You will receive a personal reply by email, usually within one working day – no automated message and no phone call you did not ask for.
- An answer from a valuer, not from a template
- We keep your question so that you need not repeat anything
- No sales pitch afterwards
Sources
Where you can verify what you have just read.
- LBMAThe London gold and silver price our daily rate is built on
- WaarborgHollandThe Dutch assay office that verifies fineness and strikes hallmarks
Rather just have it looked at?
A valuation is free and without obligation, at a location near you.