Before you sell — or before you buy something secondhand — it helps to know whether you're holding real gold or a clever fake. You don't need a lab. These seven simple tests use things you already have at home, and together they'll tell you a lot. Just remember: no single home test is 100% conclusive, so we'll finish with the one method that is.
1. Look for a hallmark or karat stamp
Real gold jewelry is almost always stamped with its purity. Check inside a ring band, on a chain's clasp, or on the back of a pendant for marks like 10K, 14K, 18K, 24K or the number equivalents 417, 585, 750, 999. Beware of stamps that include GP, GF, GE, or HGE — those mean gold-plated or gold-filled, not solid gold. Learn to read every mark in our gold hallmarks guide.
2. The magnet test
Real gold is not magnetic. Hold a strong magnet (a rare-earth magnet works best) near the piece. If it's pulled toward the magnet, it contains magnetic base metals and isn't solid gold. This is a great quick screen — but note that many fakes use non-magnetic metals, so passing this test doesn't prove a piece is real.
3. The float test
Gold is very dense. Drop the item into a glass of water. Real gold sinks quickly and sits flat on the bottom. If it floats, hovers, or drifts down slowly, it's likely hollow or fake. This won't tell you karat, but a floating "gold" piece is a red flag.
Want a free, definitive test while you watch?
Call (909) 737-24674. Check for discoloration and wear
Examine high-contact areas like the edges of a ring or the back of a clasp. If you see a different-colored metal peeking through where the surface has worn, the piece is plated, not solid gold. Real solid gold is the same color all the way through.
5. The skin test
Hold the piece firmly in your hand for a few minutes. If your skin turns green, black, or blue, the metal is reacting with your sweat — a sign of copper or other base metals, meaning it's not high-purity gold. Genuine gold won't discolor your skin.
6. The ceramic (unglazed tile) test
Drag the item lightly across a piece of unglazed ceramic or the back of a bathroom tile. Real gold leaves a gold-colored streak. A black or gray streak points to fake or plated metal. Use gentle pressure — this can leave a small scratch, so test on a hidden edge.
7. The vinegar test
Place a drop of white vinegar on the piece and wait a minute. Real gold won't react and its color stays exactly the same. If the spot changes color or fizzes, base metals are present. Rinse and dry the item afterward.
| Test | What real gold does | Reliability |
|---|---|---|
| Hallmark | Shows 10K–24K or 417–999 | Good first clue |
| Magnet | Not attracted | Screens out obvious fakes |
| Float | Sinks fast | Catches hollow fakes |
| Skin / vinegar | No color change | Detects base metals |
| Professional test | Confirms metal & karat | Definitive |
The only sure way: a professional test
Home tests are great for catching obvious fakes, but the only way to know for certain is a professional acid test, electronic conductivity tester, or XRF analyzer. These confirm both that the metal is gold and its exact karat in seconds. At SoCal Cash for Gold, we test everything for free while you watch — no obligation to sell. Once you know it's real, our guide on how to sell gold jewelry for the most cash helps you get top dollar. Can't visit our Montclair shop? Our insured mail-in service tests and pays remotely.
Free In-Person Gold Testing in Montclair
Home tests are a good screen, but if you want certainty without buying an acid kit, bring your pieces to our counter at 4994 Holt Blvd in Montclair. We'll run a professional acid, electronic, and XRF test right in front of you, for free and with zero obligation to sell. In a few minutes you'll know whether that inherited ring is solid gold, plated, or a fake — no guessing over a magnet and a glass of water at your kitchen table.
Plenty of folks from Claremont, Upland, Pomona, Chino, and Ontario stop in just to settle a "is this real?" question before a sale or an estate cleanup, and we're happy to test with no pressure to trade. We're licensed and bonded, and if the gold is genuine we'll quote it on live spot and pay up to 95% same-day in cash, Zelle, or Venmo. Coming from the east side? Our Riverside gold buyer page has the details — or just walk in with whatever you're curious about.