How to Spot Fake Gold & Silver Bullion at Home

Counterfeit bullion exists — most commonly tungsten-cored gold bars, brass-cored "sovereigns" and silver-plated copper or tungsten coins. Spotting them at home is possible without professional equipment. This is a practical checklist of tests you can run, from the obvious to the surprisingly diagnostic.

1. Visual and dimensional check

Every bullion product has published exact dimensions and weight. Use a precision scale (0.01g resolution) and digital calipers. Compare to the published spec:

• Full sovereign: 22.05 mm diameter × 1.52 mm thick, 7.988 g
• 1 oz gold Britannia: 32.69 mm diameter × 2.79 mm thick, 31.21 g
• 1 oz silver Britannia: 38.61 mm diameter × 3.00 mm thick, 31.21 g
• 1 oz gold bar (most brands): ~40 × 23 × 2 mm, 31.103 g

If the dimensions look right but the weight is off, that's a red flag — base metals (lead, brass, tungsten) substituted into a coin of the correct visual dimensions will land at a different weight. Tungsten is the exception (see below).

2. The ping test

Real silver and gold have distinctive ring tones when struck. Balance the coin on a fingertip and gently tap it with another coin or a clean metal object. You're listening for a long, high-pitched ring that sustains:

• Real silver: bright, sustained ring, ~1 second of clear tone
• Real gold (sovereign, Britannia): deeper but still musical ring, slightly shorter sustain
• Plated copper, tungsten, lead: dull thud or short, dead clack

Free apps (e.g. CoinTrust, Bullion Test) can analyse the recording and tell you whether the frequency profile matches the genuine coin. Surprisingly diagnostic.

3. The magnet test

Real gold and real silver are not magnetic. A strong neodymium magnet should not attract them at all. Try this:

• Place the piece on a flat surface. Hover a neodymium magnet 2–3 mm above. A real coin or bar will not move or stick.
• Hold the magnet to the side. Slowly tilt the piece down a smooth slope (an angled credit card works). A solid silver coin will roll fast; a real gold coin will slide. A piece containing iron, nickel or steel will slow as it passes the magnet (eddy-current braking on plated bars is a real signal too).

Catch: tungsten and lead are also non-magnetic, so a "passes the magnet test" piece can still be fake — just not that kind of fake.

4. The density (specific gravity) test

Density is the most reliable home test. Every metal has a specific gravity that's hard to fake. Tungsten happens to match gold almost exactly (19.30 vs 19.32 g/cm³), which is why tungsten-cored fakes exist — but tungsten won't match the density of silver or any other precious metal.

The "water displacement" method:

1. Weigh the dry piece on a precision scale. Note grams.
2. Put a small container of water on the scale. Tare to zero.
3. Suspend the piece by a thin string so it's fully submerged in the water but doesn't touch the container. Note the new reading on the scale (in grams, equivalent to the displaced volume in ml).
4. Density = dry weight ÷ displacement.

Reference values (g/cm³):

5. The ice test (silver only)

Silver is the best thermal conductor of any common metal. Put an ice cube directly on a silver coin: a genuine silver piece will melt the cube visibly faster than the same cube on glass, plastic, or any non-silver metal. The melt rate is dramatic — within 10–20 seconds you'll see clear water around the ice on real silver, while plated copper or stainless steel barely warms it. Doesn't work on gold (gold's thermal conductivity is high but not extreme).

6. The magnification check

A 10× jeweller's loupe is cheap and useful:

• Hallmark sharpness — counterfeits often have blurred, off-centre or shallow stamps
• Edge milling on sovereigns — should be sharp, evenly spaced, deep
• Strike quality — genuine Royal Mint coins have crisp, fully struck detail. Cast fakes show porosity, bubbles, soft details
• Surface oxidation patterns — real silver tarnishes evenly; plated fakes often tarnish in patches where the plating thins

7. The Sigma Metalytics route (for serious stackers)

A Sigma Metalytics Precious Metal Verifier (~£500) uses electromagnetic resistivity to confirm a metal's identity without damaging it. It's the closest thing to a professional assay you can have at home, and the only home tool that reliably detects tungsten-cored gold bars. If you're stacking seriously, this pays for itself fast.

What to do if you suspect a fake

1. Do not deface or damage the piece — it may still be evidence.
2. If you bought from a dealer, contact them immediately. Reputable UK dealers will refund and want to see the piece for their own records.
3. If you bought private/Facebook/eBay, document everything (photos, receipts, communications) and consider reporting to Action Fraud (UK).
4. For a definitive answer, take it to a Royal-Mint-authorised dealer or a UK assay office for a paid assay.