How to Tell If Your Gold Is Real: Tests You Can Do Before You Sell

You found something in a jewelry box — a chain, a ring, maybe a pendant that belonged to a grandparent — and you’re not sure if it’s real gold or something that just looks like it. That uncertainty is one of the most common things people bring through our door. Before you sell, it helps to know roughly what you have. Here are the most reliable ways to test gold at home, what each test can tell you, and where each one falls short.

Start With the Stamp

The most useful thing you can do costs nothing and takes thirty seconds. Find a magnifying glass and look closely at the piece for a small stamped marking, usually inside a ring band, on the clasp of a chain, or near the setting of a pendant.

Gold jewelry sold in the United States is required by the FTC to be stamped with its karat weight if it’s sold as gold. Common stamps you want to see:

• 10K or 417 — 41.7% pure gold
• 14K or 585 — 58.5% pure gold
• 18K or 750 — 75% pure gold
• 22K or 916 — 91.6% pure gold
• 24K or 999 — essentially pure gold (rare in jewelry)

These stamps mean the piece was sold as gold at that karat level. They are a strong indicator of authenticity — but not a guarantee. Counterfeit pieces exist, and stamps can be added to non-gold metal. That said, the vast majority of stamped pieces from estate jewelry, department store chains, and fine jewelry retailers are exactly what they say they are.

Stamps you do not want to see:

• GF — Gold Filled. A layer of gold bonded to a base metal core. Has some gold content but far less than solid gold and very limited resale value.
• GE, GP, or HGE — Gold Electroplated or Heavy Gold Electroplate. A microscopic surface coating of gold over base metal. Essentially no gold value.
• 1/20 14K GF — A fraction stamp combined with GF tells you the ratio. Still gold filled, not solid gold.

If the piece has one of those stamps, it is not solid gold. That doesn’t make it worthless — gold-filled pieces can still be sold — but the offer will reflect what the gold content actually is, which is a fraction of solid karat gold.

The Magnet Test

Gold is not magnetic. Neither are most of the metals used in gold alloys — copper, silver, zinc. Steel and iron are magnetic.

Run a strong magnet near the piece. If it pulls hard toward the magnet, the piece likely has a steel or iron core and is not gold, regardless of its appearance. This happens occasionally with counterfeit or costume pieces.

What this test cannot tell you: a piece can pass the magnet test and still not be gold. Copper, brass, aluminum, and most base metals are not magnetic either. The magnet test only eliminates the obvious steel fakes — it does not confirm gold.

Skin Discoloration

Real gold does not react with your skin chemistry and will not leave a green or black mark on your skin. If you’ve worn a ring for years and never noticed any discoloration, that’s a reasonable sign of actual gold content.

Copper and copper alloys, on the other hand, react with sweat and acids on skin and turn it green. Cheap costume jewelry and some brass pieces will do this reliably.

The limitation here is that this test is slow and imperfect. Some 10-karat gold alloys have a higher copper content and, in rare cases with certain skin chemistries, can leave a mild discoloration even though they are genuine 10K gold. It’s a useful data point, not a verdict.

The Float Test

You may have read that gold sinks in water because it’s so dense. This is true — gold is exceptionally dense and will sink quickly and cleanly. But so will almost every other metal. A fake gold piece made of copper, brass, or lead will also sink. The float test can tell you if something is less dense than water (hollow or very lightweight fakes might float), but it cannot confirm gold. Don’t put much weight in this one.

Acid Testing

Professional acid test kits are available at jewelry supply stores and online. They work by applying a small drop of nitric acid to the surface of the metal — either directly on the piece or on a streak rubbed onto a testing stone — and observing the reaction. Different acid concentrations react differently with different gold purities, allowing you to roughly estimate karat.

For a piece that appears to be gold:

• 18K acid applied to a 14K piece typically produces a mild reaction
• 10K acid applied to a 10K piece produces little to no reaction
• Base metal turns the acid green rapidly

Acid testing is more reliable than the magnet or skin tests, and a kit costs around twenty dollars. However, it has a significant limitation: acid can only test the surface. A gold-plated piece — if the plating is thick enough — can pass an acid test and still be a thin layer of gold over base metal. It also destroys a small amount of whatever it touches, though the mark is usually minor on jewelry.

What Professionals Use: XRF Testing

The tool used by serious buyers — and by us — is an X-ray fluorescence analyzer, commonly called an XRF gun. It fires a beam of X-rays at the piece and reads the energy signature of the elements present, identifying the exact composition of the alloy and its karat with high accuracy.

XRF testing is non-destructive, takes about ten seconds, and tells you not just whether a piece is gold but what karat it is, what alloys are mixed with it, and whether the surface composition matches the interior (useful for detecting plated pieces). It’s the industry standard for a reason.

You can’t buy an XRF analyzer for home use at a reasonable cost — professional units run into the thousands of dollars. But any reputable gold buyer will test your pieces with one before making an offer. If a buyer doesn’t test or seems to be estimating, find another buyer.

What These Tests Cannot Tell You

Even if you’ve run every test above and feel confident a piece is real gold, you still don’t know:

• The exact karat — unless you have an XRF reading
• The exact weight — you need an accurate scale, ideally one that reads in grams
• The melt value — which requires the karat, the weight, and the current spot price

These three things together — karat, weight, spot price — determine what your gold is worth as metal. All the at-home tests can do is give you a general sense of whether something is worth bringing in. The actual value calculation requires professional equipment and the current market price.

You can check today’s gold price on our live gold prices page, which we update in real time during market hours. But even with that number in hand, the offer you receive will depend on the verified karat and weighed grams of each piece.

Bring It In

If you’ve found something and aren’t sure what it is, bring it in. We test everything free, with no obligation to sell. You’ll leave knowing exactly what you have — the karat, the weight, and what it’s worth at today’s market — regardless of whether you decide to sell that day.

We buy gold throughout East Tennessee. When you’re ready for a free quote, reach out here or check current gold prices first if you want to do some math before you come in.

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