How to Tell If Gold Is Real

The fastest way to start is to read the markings, because a karat stamp and a maker's mark tell you what the piece claims to be. The most reliable way to finish is to have a jeweler test it with an acid kit or an XRF analyzer, since marks can be wrong and the popular home tests can mislead. In between, a magnet, a ceramic streak and a density check can rule things out, but none of them proves a piece is gold on its own. This guide goes through each method, what it can and cannot tell you, and the red flags that should make you stop and ask questions.

Start with what the piece claims to be

"Gold" can mean several different things, and most of the confusion starts there.

In the United States, the Federal Trade Commission's Jewelry Guides say that the word gold with no qualifier means fine gold, which is 24 karat. A piece made of a gold alloy, which is gold mixed with other metals, should state the karat, as in "14 Karat Gold" or just "14K." A piece that is only coated with gold has to say so, using terms like gold plated or gold filled. Our guide to gold filled versus gold plated covers those terms in detail.

So the first question is not "is it gold" but "what is it supposed to be": solid karat gold, a gold-filled layer, a plating, or a gold-colored base metal. The tests below answer different versions of that question.

Check the markings

Look for a stamp on the clasp, the inside of a ring band, the back of a pendant or near the post of an earring. Use a loupe or a phone camera zoomed in, since stamps are small.

Karat stamps show fineness in karats, such as 10K, 14K, 18K, 22K and 24K. Karat is a measure out of 24 parts, so 14K means 14 parts gold to 10 parts other metal, which is about 58.3 percent gold. 18K is 75 percent and 10K is about 41.7 percent.

Millesimal stamps show fineness in parts per thousand. Common ones are 375, 417, 585, 750, 916 and 999. They line up with the karat figures: 585 is 14K, 750 is 18K, 916 is 22K and 999 is 24K. These are common on imported and European pieces.

The maker's mark. The FTC's consumer advice says that near the karat quality mark you should see the name or registered trademark of the company that stands behind it, in the form of a name, symbol or initials. If a quality mark has no trademark beside it, the advice is to look at another piece. That is a sound rule for buying, though an old or repaired piece can lose or have worn off a mark.

Layered-gold stamps. Marks like GF, GP, GEP, HGE, RGP and fractions such as 1/20 identify gold-filled, plated or rolled gold pieces. These are not solid gold. They are stamped honestly when they say what they are.

A stamp is a claim, not a test. Fake pieces are stamped too, and a stamp can be added to a plated item by anyone with a die. Real marks are also sometimes absent, for example on handmade pieces, very old jewelry, or anything resized, repaired or worn smooth. So a missing stamp is a reason to test further, and a present stamp is a reason to keep going rather than to stop.

Tolerances: why a stamp is not exact

Karat stamps allow a small tolerance. Under the National Stamping Act, as noted in the Jewelry Guides, articles made of gold or gold alloy that contain no solder have a permissible tolerance of three parts per thousand, and if the part tested contains solder the tolerance is seven parts per thousand. In plain terms, 14K that tests at a hair under 58.3 percent can still be within the rules, but a piece that tests at 10K and is stamped 14K is not.

The magnet test

Gold is not magnetic. If a piece snaps firmly onto a strong magnet, it is not solid gold, or at least a large part of it is not.

The test is useful for one thing: ruling out. A strong pull is a red flag. But it is weak evidence in the other direction. Metals that fakes are commonly made from, including copper, brass, silver, lead and tungsten, are also not magnetic, so a piece that does not stick can still be fake. BullionStar puts it neatly: the magnet test rules things out more than it rules them in.

Hidden steel parts such as spring pins, clasp springs and some chain components can be magnetic on a real gold piece, so a slight attraction at the clasp does not mean the chain is fake.

The ceramic streak test

Drag the piece across the unglazed back of a ceramic tile or plate. Gold leaves a gold-colored streak. A black or dark gray streak points to a base metal or a mineral such as pyrite. This is a quick check that works on loose items, and it has two limits.

It leaves a mark on the piece, and it can scratch a finished surface, so do not use it on anything where the finish matters or on a piece that is not yours. It also does not tell you the karat.

The acid test

This is the test a jeweler or pawn shop uses, and it can tell karat levels apart when done properly. A small scratch of the piece is made on a dark touchstone, and drops of calibrated nitric acid solutions of different strengths are put on the streak. A solution labeled for 14K dissolves a streak that is below 14K and leaves a 14K or higher streak intact, and the same is true of an 18K solution for 18K. In the simplest reading, no reaction on gold, a green reaction on copper-based metal, and a milky reaction on silver.

The test has real limits.

• The scratch must reach the interior. A plated piece can give a false answer if the plating is thick enough to hide the metal beneath it, or if the scratch is too shallow to reach below the surface. Testers often file a small notch in a hidden spot to expose the metal under the surface before streaking.
• It is destructive. It leaves a mark, and the acids are hazardous. Using them takes gloves, ventilation and care, and the kits are best left to professionals when the piece has value.
• It needs practice. Reading the reaction on a touchstone is a skill, and a misread can wrongly condemn or pass a piece.

Do not apply acid to a piece you do not own, a piece with gemstones or pearls, or an antique where a mark would hurt the value.

Density

Gold is dense. Pure gold has a specific gravity of about 19.3, and a density check can catch fakes made of lighter metals. The method is to weigh the piece in air and then in water, then calculate: specific gravity equals the weight in air divided by the difference between the weight in air and the weight in water. A jewelry scale and a cup of water are enough.

Reference values quoted by BullionStar include a range of 19.13 to 19.51 for 24K gold and 14.84 to 16.12 for 18K gold. Lower karat alloys are lighter because they contain more silver, copper and other lighter metals, so the figure to compare with depends on the karat.

Density is good at one job and fails at another. It catches brass and copper cores, which are far lighter. It fails against tungsten, whose density of about 19.25 is almost the same as gold's, which is why a gold-plated tungsten piece can pass a density test. It also needs a decent scale, and pieces with stones or hollow parts give wrong numbers. Do not use density on a piece with gemstones set in it.

Professional testing: XRF at a jeweler

A jeweler, pawn dealer or refiner may use an X-ray fluorescence analyzer, known as XRF. It identifies the elements in the metal without damaging the piece. Readings typically take 5 to 30 seconds, and it can report gold purity and the other metals in the alloy, which makes it a strong tool for checking a karat claim.

XRF has a limit that matters for jewelry. It reads only the surface layer. One technical source puts the depth at roughly 10 to 50 microns depending on the metal. A piece plated with gold over base metal can read as gold if the surface is what gets measured, and if a thin plating sits on a lower-karat alloy, the reading can come out too high. GIA's laboratory documented this in its Summer 2025 Gems and Gemology lab notes, where gold plating over an alloy changed the XRF results and made the metal look like a higher karat. The remedy is to measure an exposed or filed spot, or to pair XRF with another method.

At the top of the testing ladder is fire assay, a destructive method that remains the benchmark for assay offices and refineries. It is used for bullion and refining, not for a necklace you plan to keep.

Ask a jeweler what they charge to test a piece. Our guide to jewelry appraisal explains the difference between a test and a valuation, since an appraisal states value and a test states metal.

Visual and physical red flags

• Color change at edges. A silvery, coppery or gray color showing at the edges of a ring, a clasp or a chain link points to a worn plating over a base metal.
• Tarnish or green marks. Real gold does not tarnish or oxidize under normal conditions. Dark spots or a green mark on the skin point to base metal.
• Wrong weight. A piece that feels too light for its size, or oddly heavy for it, is worth testing.
• Inconsistent color. Soldered parts that do not match the rest, or a clasp in a different color, can mean a repaired or mixed piece.
• A deal that is too good. A heavy chain priced far below the gold content is a warning, since the metal alone has a market price.
• A stamp with no maker's mark. Not conclusive, but worth testing.
• Poor stamp quality. Blurred, uneven or oversized stamps, especially ones in a spot a maker would not normally use.
• A seller who will not show it up close. Refusing a close look at the stamp, the clasp or the wear points is a reason to walk away.

What to do when you need a real answer

1. Read all the stamps, and look for the maker's mark.
2. Use a strong magnet as a quick filter, remembering that a pass proves little.
3. Weigh the piece. For anything where it matters, ask a jeweler to test an unplated surface or a filed spot with acid or XRF.
4. For high-value pieces, get a written opinion. Our guide to how to tell if fine jewelry and pearls are real covers the full set of checks, and our guide to what determines the value of fine jewelry explains how value is set once a piece is confirmed.
5. Ask the seller whether the piece is solid gold, gold filled, vermeil or plated, and ask for the answer in writing in the listing.

Buying jewelry live

When you cannot touch the piece, the questions are the ones above: what is stamped, where, what do the clasp and edges look like, and how heavy is it. A live stream lets you ask a seller to show the stamp on camera, tilt the piece in the light and show the wear points.

GG Luxury Revival, from Long Island, New York, sells luxury items and jewelry on ShopBidz, so a stream there is a place to see a piece and its marks on camera and ask questions before you bid. Prettypleaseaz, from Gilbert, Arizona, is another seller on ShopBidz you can watch. Ask each seller to show the stamp and the maker's mark, say whether the piece is solid gold or layered, and describe any wear before you place a bid.

Bottom line

To tell if gold is real, read the karat stamp and the maker's mark first, then use a magnet only to rule things out, and treat the ceramic streak and density checks as clues rather than proof. The acid test and XRF at a jeweler are the reliable methods, but each has a limit: acid has to reach the metal beneath the surface, and XRF reads only the top layer, so plating can fool both unless the tester checks an exposed spot. A stamp is a claim, not a test. For anything of value, ask a jeweler to test it, and ask a live seller to show you the marks before you bid.