You bought a gold chain, but the color looks slightly off and you are not sure it is real. This guide gives you practical ways to test gold jewelry at home before you trust or resell it. You will learn what hallmarks actually mean, which quick tests work, which ones can damage a piece, and when you truly need a jeweler.
Start with the hallmark
The fastest check is the fineness stamp. Real gold sold in Norway and most of Europe carries a small number pressed into the metal, usually inside a ring band or near a clasp.
| Stamp | Meaning | Gold content |
| 999 | 24 karat | 99.9% pure |
| 750 | 18 karat | 75% gold |
| 585 | 14 karat | 58.5% gold |
| 375 | 9 karat | 37.5% gold |
A stamp is a strong signal but not proof. Plated pieces sometimes carry marks like “GP” (gold plated), “GF” (gold filled), or “HGE” (heavy gold electroplate). If you see those letters, the item is not solid gold. Also watch for numbers that make no sense, such as “800,” which is a silver fineness, not gold.
Where to look
Use a magnifying glass or your phone camera at maximum zoom. Rings are marked inside the band, necklaces near the clasp, and earrings on the post or back. A missing stamp does not automatically mean fake, since some older or handmade pieces were never marked, but it does mean you should test further.
Quick tests you can do safely
The magnet test
Gold is not magnetic. Hold a strong magnet near the piece. If it pulls, there is magnetic metal inside, which means it is not solid gold. This test is safe and free, but it does not catch non-magnetic fakes like brass, so passing it is not full proof.
The skin and cloth test
Rub the piece firmly with a soft white cloth. Real gold leaves no black mark. Fakes often leave a dark smear as the coating rubs off. Similarly, if a ring leaves a green or black line on your skin after a day of wear, the base metal is showing through.
The weight and sound clue
Gold is dense and heavy for its size. A chain that feels suspiciously light for a thick link is a warning sign. This is a feel-based hint, not a measurement, so use it alongside other checks.
Tests to avoid at home
Acid testing and scratch tests are accurate but destructive. Nitric acid is corrosive and can burn skin and ruin the piece if you misjudge the karat. The “bite test” from old films can chip your teeth and only worked on very soft pure gold. Leave acid testing to a jeweler with proper kits and ventilation.
A real scenario
A friend inherited a “gold” bracelet with no stamp. The magnet test passed, so she assumed it was real. But a white cloth picked up faint dark residue on the clasp. A jeweler confirmed it was gold-plated brass with a solid gold clasp, which is why the magnet ignored the clasp but the plating wore off elsewhere. The lesson: never rely on a single test.
Common mistakes and how to fix them
- Trusting the stamp alone. Stamps can be faked. Fix: pair the stamp with a magnet and cloth test.
- Reading a plating code as karat. “GF” or “GP” means plated, not solid. Fix: learn the letters before you buy.
- Using acid on a piece you value. Fix: take valuable or sentimental items to a professional.
- Assuming light equals fake. Hollow gold is real but light by design. Fix: weigh it against known solid pieces of similar size.
Your at-home checklist
- Find and read the hallmark under magnification.
- Confirm the number is a gold fineness, not silver or a plating code.
- Run the magnet test.
- Rub with a white cloth and check for residue.
- Note the weight and feel.
- If two or more signs point to fake, get a professional acid or electronic test.
Conclusion and next step
No single home test is conclusive, but combining the hallmark, magnet, and cloth tests will catch most fakes and plated pieces. If value or sentiment is high, your next step is a certified jeweler who can run a safe acid or XRF test in minutes. Spend ten minutes checking before you buy, and you avoid an expensive mistake.
FAQ
Does real gold ever turn skin green?
Pure gold does not, but lower-karat gold contains copper and other alloys that can react with sweat and cause faint discoloration. Heavy green marks usually point to plated or base-metal pieces.
Can fake gold have a real hallmark?
Yes. Counterfeit stamps exist, which is why a hallmark should always be combined with a physical test rather than trusted on its own.
Is white gold tested the same way?
The hallmark logic is identical, since white gold uses the same fineness numbers. The magnet test still applies, though white gold plated with rhodium may show wear differently over time.
How much does professional testing cost?
Many jewelers offer a quick test for a small fee or free if you are buying or selling with them. XRF testing is non-destructive and fast, making it worth it for valuable pieces.
References
- Common European and Scandinavian fineness standards for precious metals (585, 750, 999 marks).