How to Spot Fake Gold: Hallmarks and Simple At-Home Checks

Start with the hallmark, not a home test

Before trying any at-home trick, look for a stamped hallmark first — it's the single most reliable signal a listing or piece gives you. Genuine solid gold carries a small stamped karat number or its millesimal equivalent ("9K" or "375", "14K" or "585", "18K" or "750", "24K" or "999"), usually on a clasp, inner band or tag. No stamp at all on a piece sold as solid gold is a reason to be cautious before you even reach for a magnet or a magnifying glass.

Read the listing wording carefully

"Gold plated", "gold filled", "gold vermeil" and "gold tone" are not karats — they describe a coating or layer over another metal, not solid gold all the way through. Only a specific karat figure ("14k solid gold") or a hallmark number points to genuine solid gold. If a listing is vague about which one it is and the price is very low, assume it's plated rather than solid; our gold-types guide covers exactly what each of those terms means for how the piece wears.

Price is the most honest test there is

Gold has real, non-trivial value by weight, so a "solid 14k" or "solid 18k" chain priced like a cheap fashion accessory should raise a flag immediately — no seller sells real gold below its metal value for long. This single check catches more fakes than any at-home trick, because it doesn't rely on you doing anything to the piece at all: just compare the price against what that weight of solid gold at that karat would actually cost.

The magnet test — useful, but not proof on its own

Real gold is not magnetic, so if a piece is strongly attracted to a magnet, it can't be solid gold and is almost certainly a base-metal fake or a heavily plated piece with a magnetic core showing through. The catch: passing this test doesn't prove a piece IS gold — plenty of non-magnetic metals (brass, copper, some stainless steel) will also sit still next to a magnet. Use it only to rule pieces out, never to confirm one in.

The float and vinegar tests — home checks with real limits

• Float test. Genuine gold is dense and sinks quickly in water rather than floating or drifting down slowly; a piece that floats or sinks very slowly is likely a lighter base metal. This only tells you something is wrong with a piece that fails it — a well-made fake can still be weighted enough to sink.
• Vinegar test. A drop of white vinegar on genuine gold causes no reaction at all; if the surface discolours or changes colour, it's plated or base metal reacting underneath. Do this on an inconspicuous spot, not the whole piece, and never on something you're not prepared to risk marking.
• Neither test is definitive on its own — they're quick screens for ruling out an obvious fake, not a substitute for a hallmark or a jeweller's proper acid or electronic test.

Skin discolouration is a clue, not a verdict

If a piece leaves a black or green mark on your skin, that usually means you're touching a base metal underneath a worn-through plating layer, or an alloy reacting with sweat and skin oils — a genuine sign the piece isn't solid gold all the way through, or that a thin plating has worn thin at a contact point. But the absence of discolouration doesn't confirm solid gold either; some fakes and low-nickel alloys simply don't react on a given person's skin. Treat this as supporting evidence alongside a hallmark check, not a standalone test.

When you genuinely need to know for sure

None of the at-home checks above are conclusive on their own, and combining several still isn't the same as a proper test. If you've bought (or inherited) a piece and actually need certainty — for insurance, resale or because you suspect it's been misrepresented — take it to a jeweller for an acid test or an electronic gold tester, or have it professionally assayed. For everyday fashion jewellery bought at fashion prices, that level of certainty usually isn't worth the cost; the hallmark and price checks above are normally enough to shop with confidence.

The quick checklist before you buy

• Look for a specific karat stamp or hallmark number, not just the word "gold".
• Treat "plated", "filled", "vermeil" and "tone" as coatings, not solid metal.
• Compare the price against what that karat and weight should actually cost — too cheap is the biggest tell.
• Use the magnet, float or vinegar tests only to rule a piece out, never to confirm one in.
• For anything you need certainty on, a jeweller's proper test beats every at-home trick combined.