Fake gold bars: how counterfeits are made and how to spot them
Counterfeit gold bars exist, and some are good enough to fool a casual look. The reassuring part is that gold has physical properties that are very hard to imitate all at once. A counterfeiter can copy the look of a bar, or its weight, or its size, but matching every measurement at the same time is difficult. Most fakes fail at least one simple test.
This guide explains the usual types of fake, the checks that catch them and where the real protection lies.
The main types of fake
Plated base metal. The crudest fakes are brass, copper or steel bars with a thin gold coating. They are lighter than real gold for their size, and a scratch or a file mark exposes the core. They are easy to catch with a scale and calipers.
Tungsten-filled bars. Tungsten is the classic choice for better fakes because its density is very close to that of gold: about 19.3 g/cm³ for both. A bar with a tungsten core wrapped in real gold can weigh the right amount and have the right dimensions. These are the fakes that justify more advanced testing.
Copies of well-known designs. Counterfeiters favor the designs people trust most: popular minted bars from major Swiss refiners, for instance. Some copies come in imitation assay cards with fake serial numbers. Our pages on PAMP Suisse gold bars and Credit Suisse gold bars describe what genuine pieces from those makers look like.
Low-purity bars sold as fine gold. Some fakes are real gold alloy, just not 999.9. They look right but contain less gold than stamped.
Checks anyone can do
None of these is conclusive alone. Together, they catch most fakes.
- Weight. A jeweler’s scale accurate to 0.01 g is enough for small bars. A 1 oz bar should weigh 31.10 g. A clear shortfall is a red flag.
- Dimensions. Measure length, width and thickness with digital calipers and compare with the refiner’s published specification for that product. A plated base-metal bar of the right weight must be noticeably larger.
- Magnet. Gold is not magnetic. A bar that sticks to a strong magnet is fake. The reverse is not true: tungsten, copper and brass are not magnetic either, so passing this test proves very little.
- Visual details. Compare fonts, logo, edge finish and serial number placement with photos from the refiner’s own website. Fuzzy lettering, uneven edges or a serial number format that does not match the series are warning signs.
- Packaging. Examine the assay card: hologram, printing quality, how the bar sits in the blister. Some refiners let you verify serial numbers or scan the bar’s surface with an app.
Checks a professional can do
When there is doubt, or for larger bars, dealers and assayers use tools that look inside or analyze the metal:
| Method | What it shows | Limits |
|---|---|---|
| XRF analysis | Surface composition, quickly and without damage | Reads only the outer layer; a thick gold shell over tungsten can pass |
| Ultrasound | Internal flaws or a different metal inside | Requires equipment and an operator who knows the bar type |
| Electrical conductivity testers | Whether the bar behaves like solid gold to a certain depth | Depth depends on the device |
| Specific gravity | Overall density | Tungsten defeats it |
| Drilling or assay | Definitive composition | Destroys or damages the bar |
The combination that matters most is a surface test plus a test that sees below the surface. That pairing is what defeats tungsten fakes.
Where the real protection lies
Testing is a safety net. The first line of defense is the source.
- Buy from established dealers with a fixed address, a long track record and a clear buy-back policy. Reputable dealers test what they buy back, so stock that has passed through them has already been checked. Our guide to buying gold bars lists what to look for.
- Be wary of prices below spot. Nobody sells genuine gold for less than its metal value without a reason. A deal that looks too good is the most reliable warning sign there is.
- Be careful with marketplaces and private sellers. Online auctions and classified ads are where most counterfeits surface. The listing advice in gold bars for sale applies here.
- Prefer bars from recognized refiners. A bar from a refiner on the LBMA good-delivery list is easier to verify and easier to resell than one from an unknown brand.
If you suspect a fake
Stop the transaction if it is still possible, keep all packaging and correspondence, and have the bar tested by a dealer or an assay office. If you paid through a platform or a card, contact them quickly: dispute windows are limited. In many countries, selling counterfeit precious metal is an offense that can be reported to the police.
The short version
Weigh it, measure it, compare it with the refiner’s specification and, if anything looks wrong, have it tested properly. Above all, buy from sellers who will still be there when you want to sell.
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