Authenticating Bullion & Spotting Fakes
Straight answer
You can catch most fakes at home by combining simple tests rather than trusting any one. Gold and silver are non-magnetic, so a strong magnet that pulls or slides slowly on the metal is a clear warning sign. Measure dimensions and weight against the published specs — counterfeits usually miss on one or the other because base metals like tungsten, lead, and brass have different densities. No single check is conclusive, so the surest protection is buying recognized bullion from a trusted dealer and keeping sealed assay packaging intact.
Counterfeit bullion is real, but it is also beatable. The same physical laws that make gold valuable — its weight, density, and non-magnetic behavior — make most fakes detectable with a magnet, a caliper, and a scale. This guide walks through the at-home and professional tests that matter, why certain products get faked most, and how smart sourcing removes most of the risk before a coin ever reaches your hands.
Why authentication matters — and where fakes come from
Gold and silver are dense, soft, chemically inert metals. Counterfeiters try to fake that profile cheaply using base metals (tungsten, lead, brass, zinc) and a thin layer of real precious metal on the outside. The problem for them is physics: no common base metal matches gold’s density of about 19.3 grams per cubic centimeter except tungsten, and tungsten is hard, brittle, and behaves differently in other tests. Silver, at about 10.5 g/cm³, is even harder to mimic convincingly. That mismatch is the crack in every fake.
Most counterfeits target the most popular, most recognized products — American Gold Eagles and Silver Eagles, Canadian Maples, Krugerrands, and well-known one-ounce bars from brands like PAMP Suisse and Credit Suisse. Why? Those items have the broadest resale market, so a fake blends in more easily and moves faster. Ironically, recognizability also helps you: known products have precise, published specifications you can measure against. Obscure or “exclusive” pieces give you nothing to compare to, which is one reason this guide steers you toward standard bullion.
At-home tests anyone can do
None of these is a lab assay, but together they screen out the large majority of fakes. Treat them as layers — a fake might pass one and fail the next.
The magnet test
Gold and silver are not magnetic. Take a strong neodymium magnet and hold it near the coin or bar, then tilt the piece and let the magnet slide down its face. On genuine metal the magnet does nothing — no pull, no drag. If the magnet sticks, jumps, or visibly slows as it slides (the “magnet slide” effect from eddy currents on ferrous fillers), you have a fake or an adulterated piece. The catch: a smart counterfeit using non-magnetic tungsten will pass this test cleanly, which is exactly why the magnet alone is never enough.
Dimension and weight
This is the single most powerful at-home check. Every reputable coin and bar has a published diameter, thickness, and weight. Buy inexpensive digital calipers and a precise scale (one that reads to 0.01 g), then measure against the official specs. Because base metals differ in density, a counterfeit that matches the weight will usually be the wrong size, and one that matches the size will be the wrong weight — it is very hard to fake both at once. A tungsten-core gold fake might nail the weight, but excess tungsten to reach gold’s mass forces dimensions slightly off. Keep a reference table of specs for what you own and check every new purchase against it.
The ping (ring) test
Silver and gold “ring” with a long, clear, high tone when balanced on a fingertip and tapped with another coin. Base-metal fakes thud or buzz with a short, dull sound. Free smartphone apps (often called “ping” or “bullion test” apps) listen to the tone and compare its frequency and decay to the known signature for that coin. It is a useful quick screen, especially for silver, but tone varies with how you hold the piece, so use it to flag suspects rather than to clear them.
Tools for the more serious buyer
The Fisch gauge
A Fisch is a precision balance-and-fit gauge machined for specific coins (such as the Gold Eagle or Krugerrand). The coin must fit through a slot of exact dimensions and balance the gauge by weight at the same time. Because it checks size and mass together against tight tolerances, it catches fakes that pass a casual look. Fisch gauges are coin-specific, so they suit buyers who repeatedly transact in a few standard products.
Ultrasonic and conductivity testers
For buyers handling larger sums, electronic verifiers read what is inside the metal, not just the surface. A Sigma Metalytics precious-metal verifier uses electromagnetic waves to measure the resistivity of the metal beneath any plating, so it can flag a tungsten-cored bar that passes every surface test. Ultrasonic thickness gauges work similarly by timing a sound pulse through the metal — a core of different density changes the echo. These tools cost a few hundred dollars and up, which makes them sensible for stackers, small dealers, or anyone buying bars regularly, and overkill for someone buying a single coin from a reputable source.
The packaging and paperwork tell a story
Many bars ship in a sealed, tamper-evident “assay card” — a blister pack with the refiner’s logo, the bar’s serial number, weight, purity, and an assayer’s signature. Keep that packaging sealed. An intact assay card from an accredited refiner (PAMP Suisse, Valcambi, Argor-Heraeus, Royal Canadian Mint, Perth Mint) preserves both authenticity assurance and resale value; a bar removed from its card is harder to sell and easier to question. Inspect the card itself for crisp printing, correct holograms, and a serial number that matches the bar. Counterfeiters fake the packaging too, so the card supports the physical tests — it does not replace them.
The best test happens before you buy
Every test above is downstream of one decision: where you bought the metal. The most reliable protection against counterfeits is sourcing from established bullion dealers with verifiable track records, not from open marketplaces.
Avoid buying bullion on Amazon or eBay. These platforms mix legitimate sellers with counterfeiters, your recourse is weak if a fake slips through, and you cannot easily verify a seller’s standing the way you can with a dedicated dealer. Reputable dealers stake their business on authenticity, buy directly from mints and accredited refiners, and offer published buy-back policies — none of which an anonymous marketplace listing guarantees. See how to vet a dealer for the full checklist, and authenticating gold for product-specific detail.
- A magnet pulls, sticks, or slides slowly — genuine gold and silver are non-magnetic.
- Diameter, thickness, or weight is off from the published spec, even slightly.
- A dull, short “thud” instead of a long clear ring on the ping test.
- Mushy or blurry detail, wrong fonts, uneven edges, or a reeded edge that looks soft.
- A broken, missing, or suspicious assay card, or a serial number that doesn’t match the bar.
- Price noticeably below the going rate for that product — fakes are sold cheap to move fast.
- Sold on Amazon, eBay, or social marketplaces by an unverified seller with weak return terms.
- Pressure to buy “rare,” “exclusive,” or unbranded pieces with no published specs to check.
How to put it together
For most buyers, the practical workflow is short. Buy recognized bullion from a reputable dealer and the authentication burden is largely handled. When you receive a piece, run the magnet test, measure size and weight against the spec, and give it a ping. If anything looks off — or for any high-value or private-party purchase — escalate to a Fisch gauge or an electronic verifier, or take it to a trusted coin shop. Build the habit of keeping assay cards sealed and recording specs, and counterfeits become an edge case rather than a worry. For more on the broader scam patterns sellers use, see the red-flags checklist; for product format choices that affect how easy something is to verify and resell, see bars vs. coins.
Are real gold and silver magnetic?
No. Both are non-magnetic, so a strong magnet should have no effect. If a magnet pulls, sticks, or slides slowly down the surface, the piece contains ferrous metal and is almost certainly fake or adulterated. A non-magnetic result alone is not proof of authenticity, because tungsten — a common gold-fake core — is also non-magnetic; combine the magnet test with weight and dimension checks.
Can a single test confirm a coin is real?
No single at-home test is conclusive. Counterfeiters design fakes to pass individual checks, but it is very hard to pass several at once. Combine the magnet, dimension, weight, and ping tests, and for high-value items add a Fisch gauge or an electronic verifier like a Sigma Metalytics device that reads beneath the surface.
Why are popular coins and bars faked the most?
The most recognized products — Gold and Silver Eagles, Maples, Krugerrands, and one-ounce bars from PAMP or Credit Suisse — have the largest resale markets, so a fake blends in and sells quickly. Their fame cuts both ways: because their specs are precisely published, you can measure any suspect piece against the official numbers.
Is it safe to buy gold on Amazon or eBay?
It carries real counterfeit risk and weak recourse. Those platforms mix legitimate sellers with bad actors, and verifying a seller’s standing is hard. Buy from established bullion dealers with verifiable histories, physical addresses, and published buy-back policies instead.