How to Spot Fake Gold and Counterfeit Jewellery

Work from strongest evidence to weakest

Fake gold covers a wide range: gold-plated base metal sold as solid, an alloy several karats below its stamp, and outright counterfeit hallmarks. The checks below are ordered deliberately, from the evidence that settles the question to the evidence that merely raises suspicion. The same sequence applies to second-hand designer pieces, where authenticating luxury jewellery adds the brand-specific checks.

The order matters because most buyers do it backwards — they run a home test, get a reassuring result, and treat that as proof. Nearly every quick check can only disprove authenticity, never confirm it. Start with the paperwork and the marking regime, and use the physical tests to catch what the paperwork misses.

The hallmark, and what it is actually worth where you are buying

Genuine gold is marked with its fineness — 999, 916, 750, 585, 375 — or a karat equivalent, usually inside a ring band, on a necklace clasp or on a bracelet tongue. The absence of any mark is a warning sign. But a stamp can be faked, so the real question is not whether there is a mark but what stands behind it.

In the United Kingdom the answer is strong. A hallmark applied by an assay office means the article has been independently tested, and three marks are compulsory: the sponsor's mark identifying who submitted it, the millesimal fineness mark, and the assay office mark showing which office tested it. The traditional fineness symbol and date letter are optional. Because the mark follows an assay rather than a claim, a UK hallmark is genuinely different from a manufacturer's stamp. Under Schedule 2 of the Hallmarking Act 1973 the approved gold standards are 375, 585, 750, 916.6, 990 and 999, so a UK-hallmarked fineness outside that list warrants a question. How to read a gold hallmark decodes the symbols individually.

In the United States there is no assay office and no compulsory independent testing. The FTC's Jewelry Guides at 16 CFR 23.3 reserve the unqualified word 'gold' for articles composed throughout of fine 24 karat gold, and require that a correct karat designation immediately precede the word where the item is an alloy. The National Stamping Act allows a tolerance of three parts per thousand on an article containing no solder, and seven parts per thousand where the tested part contains solder. A US stamp is a representation by the seller — actionable if false, but not independently verified.

India offers the strongest per-item traceability. Since 1 July 2021 a BIS hallmark has had three components: the BIS logo, the purity in both caratage and fineness, and a six-digit alphanumeric Hallmark Unique Identification number unique to the individual article and traceable by the buyer. Permitted caratages under IS 1417:2016 are 14K (585), 18K (750), 20K (833), 22K (916), 23K (958) and 24KS (995).

Hong Kong regulates the transaction rather than the metal. A retailed gold article must bear a fineness mark in the specified form, the invoice must state the fineness — part by part where parts differ — and a notice of not less than 210 mm × 297 mm setting out the legal requirements must be displayed at the point of supply. No mark and no invoice stating fineness means something is wrong.

The magnet test: fast, free, and only ever disproves

Gold is not magnetic. If a strong magnet attracts the piece, it contains magnetic base metal and is not solid gold. This catches a large share of cheap fakes in about two seconds and costs nothing.

What it cannot do is confirm anything. Several non-magnetic metals can be used as a core or a substitute, so a piece that ignores the magnet has passed one filter out of several. Clasps, springs and pins are also frequently made from steel on otherwise genuine jewellery, so test the body of the piece rather than the fittings before drawing a conclusion.

Density and weight: the check that catches the good fakes

Gold is unusually dense, and this is where a well-made fake tends to fail. A piece that feels light for its size is suspect, and the impression is immediate to anyone who has handled genuine gold — comparing against a piece you know to be real is the quickest way to calibrate.

Density can be measured rather than estimated, which is what makes it useful. Weighing a piece and measuring its water displacement gives a density figure that can be compared against the expected value for the claimed alloy. This is the check that exposes plated base metal and hollow construction, both of which can otherwise look and mark correctly. It is not conclusive on its own, because a substitute chosen specifically to match gold's density will pass it, but it eliminates most of what a magnet misses.

A related tell: know what the piece should weigh. Purity and weight together determine metal content, and the relationship between 18K and 999 sets out how to convert a stamped fineness into actual grams of gold. A seller who cannot state weight and fineness together is not selling on the metal.

Surface checks, and their limits

Two further checks are widely recommended and both need caveats.

Dragging a piece across unglazed ceramic produces a gold-coloured streak from real gold and often a dark streak from plated base metal. It works, but it can abrade the item, so it is a check for something you already suspect rather than a routine step on a piece you might buy.

Discolouration of the skin, or of the item at wear points, indicates plating wearing through to a base metal underneath. This is genuinely informative on a piece that has been worn, and useless on something new.

Acid testing and electronic testers give a far more definitive reading, and both are available from any jeweller. For anything beyond a trivial purchase this is the step that actually settles the question — and the important detail is that it should be done by someone who is not the person selling you the item. Once a piece is confirmed genuine, how to care for gold jewellery covers keeping it that way, since aggressive cleaning damages plating and softer high-karat pieces alike.

The source is the protection the tests are not

Every check above is damage limitation. The reliable defence is buying from a seller whose purity claims are backed by something — an assay office, a traceable hallmark number, a statutory invoice, or a published specification you can hold them to.

That means established retailers and recognised bullion dealers rather than an unknown seller with an attractive price. A retailer such as Chow Sang Sang sells marked high-purity gold with stated fineness; a bullion dealer such as Silver Gold Bull publishes specifications and live pricing against spot. In both cases the claim is documented at the point of sale, which is what gives you recourse.

The single largest red flag remains a price meaningfully below the metal value. Gold has a floor set by what the metal is worth, and a seller offering to go beneath it is telling you something about the item. When the amount matters, get an independent appraisal before you pay — not after. If you are buying bullion rather than jewellery, how to buy investment gold covers the equivalent checks on premiums and recognised products. Nothing here is financial advice.

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