Fast answer: No single home test is proof on its own, but stack a few and you'll catch almost any fake. Start with the hallmark stamp, then a magnet test (real gold is not magnetic), then look for skin discoloration and wear-through. For anything you're paying real money for, finish with a professional acid or electronic test — it's cheap insurance.
A stamp that says "14K" is a claim, not a guarantee — fakes are stamped too. The goal isn't one magic test; it's stacking several quick checks so a fake has nowhere to hide. Here are the six that matter, from easiest to most definitive.
Read the hallmark stamp
Real gold is almost always stamped with its purity, usually on the clasp or a small tag: 417/416 (10k), 585 (14k), or 750 (18k). Watch for tells of plating: letters like GP (gold plated), GE/HGE (gold electroplate), GF (gold filled), or RGP (rolled gold plate) mean it is NOT solid gold. No stamp at all is a red flag — but a stamp alone isn't proof.
The magnet test
Gold is not magnetic. Hold a strong magnet (a rare-earth magnet, not a fridge magnet) to the chain. If it pulls, sticks, or drags, there's magnetic metal inside — it's plated or fake. Passing this test doesn't prove it's gold (some non-magnetic metals fake it), but failing it is a near-certain bust.
Look for wear-through and discoloration
On plated pieces, the gold layer rubs off at high-contact points — clasp, edges, the back of links — revealing a different metal underneath. Green or black marks on your skin point to base metal and plating, not solid gold. Solid gold doesn't tarnish or turn skin green.
The acid test
Gold-testing acid kits are inexpensive. A tiny scratch on a test stone is treated with acid graded for each karat; real gold of that karat won't dissolve, while plating or lower-grade metal reacts. It's mildly destructive and uses corrosive acid, so for valuable pieces many people leave this to a jeweler.
Weigh and measure (density check)
Gold is dense — about 19.3 g/cm³ for pure gold, and still high for 14k–18k. A piece that looks big but feels suspiciously light is often hollow or plated. A jeweler can do a precise specific-gravity test; at home, an unusually light "solid" chain is a warning sign worth following up.
Get a professional test
For anything expensive, a jeweler's electronic gold tester or XRF analyzer reads purity in seconds without damage, and a formal appraisal documents it. If you're buying secondhand or spending real money, this is the step that turns "probably real" into "confirmed."
Where fakes hide on a gold chain
The most common deceptions aren't outright fakes — they're plated or filled pieces sold with gold-priced language. A "14k gold" listing may quietly be "14k gold plated" or "14k gold filled." Those are real terms for real (cheaper) products, but the price should reflect plating, not solid gold. Understand the difference in our solid vs plated vs filled guide so the wording can't trick you.
Buying online or secondhand
You can't magnet-test a photo. Online, lean on the seller's reputation, an explicit solid-gold karat stamp in the listing, a stated gram weight, and a clear return policy — then verify the moment it arrives. On secondhand marketplaces, assume nothing until you've run the tests above or had a jeweler confirm it before money changes hands.
Frequently asked questions
Does real gold stick to a magnet?
No. Pure and alloyed gold (10k, 14k, 18k) are not magnetic. If a chain is attracted to a strong magnet, it contains other metals and is plated or fake. Note that some fakes use non-magnetic base metals, so passing the magnet test alone isn't full proof.
What do the numbers 585 and 750 mean on a chain?
They're European-style purity hallmarks: 585 means 58.3% gold (14k) and 750 means 75% gold (18k). 417 or 416 means 10k. Letters like GP, GF, GE, or HGE mean the piece is plated or filled, not solid gold.
Can I tell if gold is real without any tools?
Partly. Check the stamp, look for wear-through to a different metal at the clasp and edges, and watch for skin discoloration. These catch many fakes, but a magnet and, ideally, a professional test give you certainty.
Is the vinegar test reliable?
Not really. Home tricks like vinegar or bite tests are unreliable and can damage a piece without giving a clear answer. Stick to the stamp, magnet, wear, and — for anything valuable — a professional acid or electronic test.