High karat gold has a color nothing else quite imitates. Antique Old Cut Diamond Ring, 23K gold, 1895
The honest answer first: at home you can get to "very probably real" or "very probably not", and that is worth doing. Certainty comes from an XRF machine, which reads the exact alloy in seconds without a scratch. I test every single piece that passes through my hands on an XRF machine before it is sold, so nothing in my shop rests on guesswork. But you probably do not have one on your kitchen table, so here is what you can do at home instead.
I buy and sell antique gold for a living, and every batch I look through contains something gilded pretending to be solid. These are the checks that sort most pieces before the machine confirms it, cheapest and safest first.
Step 1: Read the marks
Most real gold made in the last 150 years is stamped: 333, 375, 585, 750 or a karat mark like 14K or 18K. Find the mark inside the ring band, on the clasp tongue of a chain, or on the pin of a brooch, and you are most of the way there.
Just as important are the marks that tell you a piece is not solid gold:
| Mark | What it actually means |
|---|---|
| GF, 1/20 12K GF | Gold filled: a bonded layer of real gold over base metal |
| RGP, rolled gold | Rolled gold plate: a thinner bonded layer |
| GP, HGE, GEP | Electroplated: a microscopically thin layer |
| 925, 830, 800 | Silver, even when it looks gold: gilded silver is everywhere in antique jewelry |
| No mark at all | Means nothing either way on antiques: test further |
Two warnings from experience. First, a mark can be faked, and cheap cast fakes often carry a crisp "750" precisely because buyers stop looking once they see it. A mark is evidence, not proof. Second, many genuinely old pieces were never marked, or the mark was cut away during a resize, so an unmarked piece is not automatically fake. I wrote a full guide to reading the real marks: How to read gold hallmarks, and a separate one for English hallmarks.
Step 2: The magnet test, done honestly
Real gold is not magnetic, so if a strong neodymium magnet snaps onto the piece, it is not solid gold. That much is true. What the internet leaves out is the reverse: most fakes are brass, copper or silver based, and those are not magnetic either. A piece that ignores the magnet has passed a test that most fakes also pass.
One trap I see constantly: the clasp. Many genuine gold chains and bracelets have a steel spring inside the clasp, so the clasp reacts faintly to a magnet while the rest of the piece is perfectly real gold. Test the chain itself, not the clasp.
Step 3: Feel the weight
Gold is heavy in a way your hand learns quickly. Pure gold is 19.3 g/cm3, about two and a half times brass. Even 14K, at roughly 13 g/cm3, feels noticeably denser than any base-metal copy of the same size. A "gold" chain that feels like it could float away is telling you something. This test takes practice and works best when you can compare two similar pieces, but it is the one dealers actually use across a market table.
Solid 14K feels denser in the hand than any copy. Antique Danish Old Cut Diamond Ring, 1.20 ct, 14K gold
Step 4: Look at the wear points
Plating wears through; solid gold just wears. Take a loupe, or your phone camera zoomed in, and look at the spots that rub: the edges of a ring band, the high points of a pattern, the links of a chain where they touch each other. On a plated piece you will see a different colored metal peeking through, often grey, coppery or brassy. On solid gold, worn spots are simply more gold, perhaps a slightly different shade where a polish has thinned the surface.
This is my favorite test for antiques, because age helps you: a hundred years of wear will have opened up any plating somewhere.
Step 5: Skin, color and other half-truths
A green or black mark on your skin means the alloy contains a lot of copper or nickel at the surface. Plated and base-metal pieces do it often; low karat real gold like 8K or 9K can occasionally do it too, especially with sweat or perfume. So discoloration is a bad sign, but not a verdict. The bite test is a movie prop: teeth are harder than you think, gold is softer than you think, and all you get is a dented antique.
What I would never do at home
Acid test kits and scratch stones work, and pawnshops use them daily, but they take a visible bite out of the surface. On a modern chain destined for scrap, fine. On an antique, you are carving a divot into an object that survived two centuries intact. The same goes for filing a notch "to see the core". If a piece matters enough to test, it matters enough to test properly.
The proper test is XRF, X-ray fluorescence. It reads the exact alloy in about ten seconds and touches nothing, which is why it is the test I use on every piece I sell. Most serious jewellers and gold buyers have the machine too, and a reading usually costs little or nothing with any purchase or valuation. Density testing in water is the older non-destructive route and still works, but only on pieces without stones, since a set stone throws the whole calculation.
Frequently asked questions
How can I test gold at home without acid?
In order: read the marks, check the piece is not magnetic, weigh it in your hand against something you know is real, and inspect the wear points under magnification for a different metal showing through. Together those four sort out most pieces.
Does real gold stick to a magnet?
No. Gold is not magnetic. But most fakes are not magnetic either, so the magnet can only condemn a piece, never approve it. And test the chain rather than the clasp, because many real clasps contain a small steel spring.
Is my jewelry real gold if it is stamped 585?
Probably: 585 means 14 karat, 58.5% gold. But stamps can be forged, so treat the mark as strong evidence rather than proof, and check the wear points too.
Does real gold turn your skin green?
Usually not, but low karat gold sometimes can, since 8K or 9K gold is mostly other metals. A green mark makes plating more likely; it does not settle the question on its own.
How much does it cost to have gold tested?
An XRF reading at a jeweller or gold buyer is often free with a valuation, and rarely more than a small fee. It is non-destructive and takes seconds, which makes it the obvious choice for anything antique.
Is gold filled jewelry worthless?
No. Gold filled pieces contain a real bonded layer of gold and many antique examples are lovely, collectible and wearable. They are just not solid gold, and should be priced accordingly, which is roughly a tenth or less of a comparable solid piece.
Everything in my shop is solid gold or solid silver, XRF-tested before it goes up for sale, and described with its marks. If a piece has no marks, the listing says so, and says how it was verified instead.
Read next: How to read gold hallmarks · Why gold jewelry is a great investment · How to date antique jewelry
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