Real gold testing at home is not as dramatic as the movies make it look. You do not need a jeweler's loupe or an acid kit to get a good sense of whether a piece is solid gold, gold-filled, or plated. A handful of simple tests, done together, will tell you more than enough to avoid buying a fake, and you can do most of them with things you already have at home. No single home test is conclusive, but a combination of three or four tests gives you a reliable answer.
The first test costs nothing. Turn the piece over and look for a tiny stamp. On a ring, it is inside the band. On a necklace, it is on the clasp. On a bracelet, it is on the clasp or the end tag. Real gold jewelry should carry a karat stamp: 10K, 14K, 18K, 22K, or 24K. European pieces use the parts-per-thousand numbers: 417 for 10k, 585 for 14k, 750 for 18k, 916 for 22k. The stamp is usually small, and you may need a magnifying glass or the camera on your phone zoomed in to read it.
The absence of a stamp is a warning sign, but not a verdict. Vintage pieces, handmade pieces, and pieces that have been resized many times sometimes lose their stamp through polishing. The presence of a stamp is also not proof, because counterfeit pieces are routinely stamped with fake marks. Treat the stamp as a clue, not a conclusion. If the stamp says 14K and the rest of the tests check out, you are probably fine. If the stamp says 14K but the magnet test below picks it up hard, the stamp is lying.
| Stamp you see | What it means |
|---|---|
| 10K / 417 | 41.7% solid gold |
| 14K / 585 | 58.3% solid gold |
| 18K / 750 | 75.0% solid gold |
| 22K / 916 | 91.7% solid gold |
| GF / 1/20 14K GF | Gold-filled, not solid |
| GP / GEP / HGE | Gold-plated, not solid |
| Plated on brass | Fashion jewelry, not gold |
Gold itself is not magnetic. A strong neodymium magnet should not pull on a solid gold piece. If the magnet clamps onto the jewelry, the piece contains a magnetic metal, usually steel or iron, and it is not solid gold. This is one of the fastest and most useful home tests, because solid gold, silver, platinum, palladium, and copper are all non-magnetic. If a necklace snaps to a magnet, it has a steel core or a steel clasp, and it is plated over.
The catch is that the magnet test can only tell you that something is fake. It cannot tell you that something is real. A brass, copper, or aluminum core under gold plating is also non-magnetic, so a non-reaction does not prove the piece is solid gold. You need the other tests to narrow it down. Use a strong rare-earth magnet, not a fridge magnet, because a weak magnet will not pick up the small amount of iron in some gold alloys.
Put the piece on for a few hours and watch the skin underneath. Real solid gold does not turn skin green or black. A green mark means the metal touching your skin is copper or brass, which happens when a plated piece has worn through. A black mark means the metal is reacting with the sulfur in your skin lotion or your sweat, which is common with low-quality alloys. A faint gray mark on the finger from a ring is normal with any metal, including silver, but a persistent green or black ring around the skin is a red flag.
The skin test is slow and imperfect, because it can take hours or days to show up. It also depends on your body chemistry, which varies. But it is a useful confirmation after the magnet and stamp tests. If you wear a gold ring for a day and your finger turns green, the ring is not solid gold, no matter what the stamp says.
Drop the piece in a small cup of white vinegar and leave it for about five minutes. Real gold will not react, discolor, or change. Fake gold, or gold-plated base metal, will often darken or change color where the vinegar touches it, because the acid reacts with the underlying brass or copper. This test is safe for solid gold, but you should rinse the piece thoroughly afterward. Do not use it on pieces with pearls, opals, or other soft stones, because vinegar will etch those.
The vinegar test is a rough screening tool, not a lab result. A piece that does not react could still be high-quality gold-filled or vermeil rather than solid gold. But a piece that darkens in vinegar is definitely not solid gold, which is useful when you need a quick no.
Gold is dense. A small piece of gold should feel heavy for its size. Solid 14k gold has a density around 12.9 to 14 grams per cubic centimeter, while brass is around 8.5 and steel is around 7.8. If a ring looks thick and substantial but feels surprisingly light in your hand, it may be hollow or plated. The density test is subjective, but after you have handled a few real gold pieces, you start to feel the weight difference. A heavy piece for its size is a good sign. A light piece that looks big is a warning.
You can make this quantitative with a small kitchen scale and a cup of water. Weigh the dry piece, then weigh it suspended in a cup of water without touching the sides. The ratio of the dry weight to the water displacement gives you the density. Solid gold will be around 13 to 19 depending on karat. Brass will be around 8.5. This is the same principle a jeweler uses for archimedes testing, and it is surprisingly accurate.
When you need a definitive answer, a jeweler has three tools a home tester does not. An acid test applies a tiny drop of acid to a scratch on the back of the piece and watches whether the scratch dissolves. It is mildly destructive but conclusive. An x-ray fluorescence (XRF) gun shines x-rays at the surface and reads the metal composition, which tells you the exact karat without scratching anything. A diamond tester, which is actually a thermal probe, is not for gold; it is for diamonds. XRF is the gold standard for non-destructive testing, and most reputable jewelers will run it for a small fee or for free if they hope to sell you something.
If you are buying a piece worth more than a few hundred dollars secondhand, it is worth the $20 to $50 for an XRF reading. It tells you the exact karat, whether there is plating, and whether the stamp on the inside matches the actual metal. A seller who refuses an XRF test on an expensive piece is telling you something you need to hear.
The most common fake is a gold-plated tungsten or brass core stamped 14K. The magnet test usually misses this because tungsten and brass are non-magnetic, but the density test catches it because tungsten is less dense than gold and brass is much less dense. The second common fake is a gold-plated silver piece, which looks and feels like gold but has no gold value. The vinegar test catches this because the silver underneath can react. The third is a hollow gold piece that is sold as solid, which the weight test catches immediately.
If you are buying from an online marketplace, ask the seller for a short video of the stamp, the weight on a scale, and the magnet test before you buy. A legitimate seller will send all three. A seller who refuses is selling something they do not want you to inspect. For more on pricing and what is fair, see how much to pay for a gold ring.
You cannot get a perfect answer at home, but you can get a strong signal. Check the stamp, run the magnet test, watch for skin discoloration, and weigh the piece in your hand. If all four line up, the piece is almost certainly real. If any of them contradict the stamp, take it to a jeweler for an XRF reading before you spend real money. Home testing will not replace a professional appraisal, but it will save you from most of the obvious fakes.
Jewelers use an acid test as a quick, low-cost way to confirm karat. They make a tiny scratch on a hidden part of the piece, usually the inside of the band, and apply a drop of acid formulated for a specific karat. If the scratch dissolves, the metal is below that karat. If it stays, the metal is at or above that karat. The jeweler repeats with a higher karat acid until they find the breakpoint. The whole process takes a minute and leaves a micro-scratch that is invisible once the piece is polished.
The acid test is destructive, which is why jewelers do it on hidden surfaces. It is also slightly unpleasant, because the acid has a strong smell. But it is far more reliable than any home test, and it is the standard method for estate and secondhand pieces. If you are buying a piece worth more than a few hundred dollars, ask the seller for an acid test before you hand over the money.
X-ray fluorescence spectroscopy is the non-destructive gold standard. The gun fires low-energy x-rays at the surface of the metal, which excites the atoms and causes them to emit characteristic x-rays. The gun reads those emissions and reports the exact percentage of each metal in the alloy. It tells you the gold content, the copper content, the silver content, and any trace metals, down to fractions of a percent. It will also detect plating, because the x-rays only penetrate a few microns and the composition shifts at the plating layer.
An XRF reading is conclusive. If the gun says the piece is 58.3% gold, it is 14k, no matter what the stamp says. If the gun says the surface is 99% copper with a thin gold layer, the piece is gold-plated, no matter what the stamp says. Most reputable jewelers and pawn shops have an XRF gun, and many will run it for a small fee or for free if they hope to buy the piece from you.
Estate sales and flea markets are where home testing matters most. The seller often does not know what the piece is, and prices are negotiated. Before you make an offer, run the stamp, magnet, and weight tests. If the piece passes all three, make an offer based on the gold value plus a small premium for the design. If the piece fails one of the tests, walk away, no matter how pretty it is. Estate sales are full of gold-plated pieces that look like the real thing, and the home tests are your only protection.
If you find a piece that passes the home tests but you want certainty, offer to pay for an XRF reading at a nearby jeweler before you finalize the purchase. Most sellers will agree, because the reading confirms the value and justifies the price. A seller who refuses an XRF test on a piece they claim is solid gold is hiding something.
Fake stamps follow predictable patterns. Cheap plated pieces are often stamped 14K or 18K without the registered trademark symbol that real U.S. manufacturers use. Stamps on very old pieces sometimes use unusual spellings or spacing. Stamps on pieces sold online often look too clean and too large, because counterfeiters apply them after manufacture. Real stamps are usually tiny, slightly uneven, and positioned in a standard location inside the band. If the stamp looks printed on rather than stamped into the metal, it is likely fake.
For more on pricing and fair value, see how much to pay for a gold ring.
If the stamp says 14K, the magnet test is negative, and the weight feels right, but you are still not sure, the next step is a professional reading. Take the piece to two jewelers and ask for an XRF reading. Most will do it for free or for a small fee. Compare the readings. If both jewelers agree the piece is 14k, you can trust it. If one says 14k and the other says plated, the first jeweler may have missed a plating layer, and the second is probably right.
If you are buying the piece secondhand and the seller will not let you take it to a jeweler, walk away. A legitimate seller who knows the piece is real will let you verify it. A seller who refuses is selling something they do not want inspected.
The home tests described above are for solid gold. Gold-filled and gold-plated pieces behave differently. A gold-filled piece will pass the magnet test, will not turn your skin green while the gold layer is intact, and will feel heavier than a plated piece of the same size. But it is not solid gold, and the stamp will say GF rather than 14K. If the stamp says GF, you know exactly what you have, and you should pay accordingly.
A gold-plated piece can pass the magnet test if the core is brass, which is non-magnetic. It will not pass the vinegar test for long, because the acid will eventually reach the brass and discolor. It will also wear through in months, revealing the base metal. If you think a piece is plated, treat it as fashion jewelry and price it accordingly.
Vintage and antique gold jewelry often has unusual stamps. A piece from the 1920s may be marked 14K with a maker's mark that is no longer in business. A piece from Europe may be marked with a hallmarks system that is different from the U.S. stamp. These stamps are not fakes; they are just old. If you are buying a vintage piece, ask the seller for photos of the hallmark, and look up the hallmark online. Many vintage gold pieces are genuinely solid and are worth more than their melt value because they are old.
For more on what makes jewelry hold value, see gold as investment versus jewelry.
If you do only one home test, do the magnet test. It takes ten seconds, it uses a cheap magnet you can buy online, and it catches the majority of fakes. If a strong neodymium magnet pulls on the piece, it is not solid gold, no matter what the stamp says. If it does not, you have narrowed the field but not proved anything. The magnet test is the fastest, cheapest, most reliable screen, and it is the one every jeweler does first.
Combine it with the stamp check and the weight test, and you have covered the obvious fakes. For anything worth real money, follow up with an XRF reading at a jeweler. Home testing will not replace a professional, but it will keep you from buying the obvious fakes that circulate on online marketplaces.
Real gold stamps are small, crisp, and positioned in a standard location. Fake stamps are often too large, too deep, or slightly crooked. Counterfeiters stamp the metal after manufacture, which leaves a cleaner impression than the older hammer stamps used by real manufacturers. If the stamp looks too perfect, or if it is on a part of the ring where no real manufacturer would put it, be suspicious. When in doubt, the XRF gun does not care what the stamp says.
Home tests are screens, not verdicts. If the piece is worth more than a few hundred dollars, spend the $20 to $50 for an XRF reading. It is the only way to know for certain, and it tells you the exact karat. A seller who knows the piece is real will welcome the test. A seller who refuses is selling something they do not want inspected. The $50 is cheap insurance against a $500 mistake.
A professional jeweler starts with the same magnet test you do, then moves to a 10x loupe to inspect the stamp and the finish, then runs an acid scratch on a hidden surface, and finally an XRF reading if the piece is valuable. You can replicate the first three steps at home. The XRF gun is the one tool you cannot buy cheaply, which is why it is worth paying $20 to $50 for a reading on anything valuable. The combination of home tests catches most fakes, and the professional reading catches the rest.
If you are buying from a reputable dealer, you can skip the home tests and trust the stamp. If you are buying from an online marketplace, an estate sale, or a flea market, run the home tests first. The five minutes you spend with a magnet and a magnifying glass will save you from most of the obvious mistakes. For more on what real gold looks and feels like, see the karat guide.
Can a home test perfectly identify gold? No, but it catches the obvious fakes. A magnet test, a stamp check, and a weight comparison will screen out most plated pieces. For anything valuable, an XRF reading at a jeweler is the definitive answer. How much does an XRF cost? Usually $20 to $50, and many jewelers do it for free if they hope to sell you something. How do I test gold-filled? The stamp will say GF, and the piece will not pass an acid test for solid gold. That is normal; gold-filled is a different product. For more, see the gold topic hub.