How to Spot Fake Gold: Tests You Can Actually Do

Most fake gold is caught by two things: buying from a reputable dealer, and knowing what the real item weighs.

Everything below is for the situations where those two aren't available — a private sale, an inheritance, a piece bought years ago from somewhere you no longer remember.

Start with the hallmark

Real gold is almost always stamped. Look for one of two systems, usually on a clasp, an inner band, or the edge of a bar:

• Karat: 24K, 22K, 21K, 18K, 14K
• Fineness: 999, 916 (22K), 875 (21K), 750 (18K), 585 (14K)

Marks to treat as warnings: GP (gold plated), GF (gold filled), GEP (gold electroplated), HGE (heavy gold electroplate), or 1/20 12K style fractions. These all describe a thin gold layer over another metal, and are legally accurate descriptions of something that is not solid gold.

The magnet test

Gold is not magnetic. Neither is silver. If a strong magnet pulls the item, it contains a significant amount of iron or steel and is not solid gold.

Use a proper neodymium magnet, not a fridge magnet.

What it catches: cheap fakes with steel cores. What it misses: everything else. Copper, brass, lead and tungsten are all non-magnetic. Passing this test proves very little — it only rules out the laziest fakes.

The density test

This is the strongest test you can run at home, because density is a physical property that is very hard to fake with cheap metals.

Gold's density is 19.32 g/cm³ — far higher than almost anything it might be substituted with.

1. Weigh the item in grams.
2. Fill a measuring container with water and note the level.
3. Submerge the item fully and note the new level. The difference in millilitres is its volume in cm³.
4. Divide weight by volume.

The method is imprecise for small or intricate items, and gemstones and hollow sections throw it off completely. But on a solid bar or a plain band it is decisive against ordinary fakes.

The ping test

Struck gently, precious metals produce a long, high, sustained ring. Base metals give a short dull thud.

There are phone apps that record the strike and analyse the frequency. It is a genuine and widely used check for bullion coins, though it needs a clean strike and a quiet room, and it works far better on coins than on jewellery.

The acid test

Jewellers use graded nitric acid solutions on a scratch of the metal, matching the reaction to a karat. It is accurate and it is the standard trade method.

It is also destructive — it requires marking the item — and it involves handling acid. This is a test to have done by a jeweller, not one to attempt on something valuable at home.

The fake that defeats almost everything

Tungsten. Its density is 19.25 g/cm³ — within a fraction of a percent of gold. A tungsten core with a thick gold coating passes the magnet test, passes a visual inspection, passes the hallmark check, and passes the density test.

The practical defences: buy from a dealer who will buy it back, prefer bars with serial numbers from recognised refiners, and for anything substantial, pay for professional testing.

Buying jewellery specifically

• Ask for the price broken down into metal weight × today's gold rate, and making charges separately. A seller who refuses is hiding one of the two.
• Weigh it in front of you on a scale you can see.
• Get a written invoice stating karat, weight and the gold rate used. Without it you have no basis for a return and no proof of what you were told.
• Ask the buy-back price before purchasing. It is the truest measure of what you are paying, and the answer is often clarifying.

The short version

Check the hallmark, run a magnet, and calculate density — in that order, at home. None of it defeats a tungsten core, which is why where you buy protects you more than any test you can perform. A dealer with a reputation and a buy-back offer is worth more than every home test combined.