How to Test If Gold Is Real: 6 Home Methods That Actually Work

What each test can and cannot prove — in plain language.

Before you take a piece of jewelry to a buyer, or before you hand cash over at a market stall, it helps to know whether you are holding real gold in the first place. A professional assay with fire or XRF is the only definitive answer, but a handful of simple tests will catch most of the outright fakes that circulate in the scrap market. Here are six, ranked roughly from least to most reliable, with honest notes on what they actually prove.

1. Read the hallmark

The quickest test is no test at all: find the stamp. Genuine gold jewelry is almost always marked with its purity. Common stamps you will see:

999 or 24K — 99.9% pure gold
916 or 22K — 91.6% pure (common in India, Middle East)
875 or 21K — 87.5% pure (Gulf states, Egypt)
750 or 18K — 75% pure (European standard)
585 or 14K — 58.5% pure (North American standard)
375 or 9K — 37.5% pure (UK, some European)

A stamp of GP, GF, HGE, RGP, or 1/20 means gold plated, gold filled, heavy gold electroplate, rolled gold plate, or gold-over-base respectively — in every one of those cases, the item is mostly not gold. A stamp of 925 is sterling silver, not gold.

Limitations: stamps can be forged, and old or heavily worn pieces may have lost their mark. Presence of a stamp is a good sign but not proof.

2. The magnet test

Gold is not magnetic. Hold a strong neodymium magnet (a rare-earth magnet, the small silver-colored discs) close to your piece. If the item jumps, sticks, or is visibly tugged toward the magnet, it contains a significant amount of iron or steel and is not solid gold.

This test is cheap, fast, and decisive for the common fakes that use a steel or iron base. What it does not catch: fakes made from copper, brass, lead, tungsten, or non-magnetic stainless steel will all pass the magnet test. Passing the magnet test tells you "probably not a steel-core fake" — nothing more.

3. The density (water displacement) test

Gold is dense. Very dense. Pure gold weighs 19.3 grams per cubic centimeter. This is nearly double the density of lead (11.3) and more than double the density of copper (8.9) or silver (10.5). The only common metal that matches gold's density is tungsten, which is why sophisticated counterfeit bullion is sometimes tungsten-cored.

To measure density at home you need a kitchen scale accurate to 0.1 grams and a graduated cylinder or measuring cup with clear millilitre markings:

Weigh the piece dry and record the grams.
Fill the cylinder with enough water to fully submerge the piece, and note the starting water level.
Lower the piece in (tie it to a thread if needed) and note the new water level.
The difference in millilitres equals the volume in cubic centimetres.
Divide weight by volume. Compare to expected density for your karat: 24K is about 19.3, 22K about 17.7, 18K about 15.5, 14K about 13.1.

This test is harder to fool than the magnet test, but it is fiddly. Small pieces produce small water-level changes, so measurement error stacks up quickly. For a chain or ring, expect your reading to be within roughly 10% of the true density at best.

4. The ceramic streak test

Find an unglazed ceramic tile — the back of a bathroom tile works, or an unglazed ceramic plate. Drag the gold piece firmly across the unglazed surface. Real gold leaves a gold-colored streak. Fake gold, including most gold-plated items once the plating wears through, leaves a black or grey streak.

This test is destructive — it scratches the piece — so do it on an inconspicuous spot. It also fails on thickly plated items where you do not cut through the plating. Useful as a quick confirmation, not a first line of defense.

5. The vinegar test

White vinegar (acetic acid) does not react with gold. Drop a few drops on a clean surface of the piece and wait one to two minutes. Real gold shows no change. Fake gold may darken, turn green, or discolour at the spot.

The vinegar test is gentle and non-destructive, but it is also a weak test. Many base metals and plated items will pass it. Use it to rule out the cheapest fakes, not to confirm authenticity.

6. The nitric acid test

This is the traditional jeweler's test and the most reliable of the home methods, but it requires real chemistry-store nitric acid and appropriate safety: gloves, goggles, ventilation, and a safe surface. Do not attempt it unless you are comfortable handling corrosive acids.

The procedure: file a small notch in an inconspicuous spot (to cut through any plating), place a drop of nitric acid on the notched area, and watch the reaction.

No reaction — gold of 18K or higher.
Slight milky reaction — 14K.
Brown or green reaction — base metal or very low-karat plate.
Vigorous bubbling — not gold.

Jeweler's acid test kits sold for under $30 contain graded acid strengths for 10K, 14K, 18K, and 22K, which lets you narrow purity by the reaction. This is closer to a professional result but still not definitive for plated items with thick gold over a gold-coloured alloy.

What home tests cannot do

No combination of home tests will beat a modern counterfeit made from tungsten cored and gold plated to sufficient thickness. Nor will they reliably tell 14K apart from 16K. For items of high value — anything over a few hundred dollars — pay a reputable jeweler to run an XRF (X-ray fluorescence) scan. XRF is non-destructive and gives you exact karat in seconds.

A sensible workflow

For a typical piece of jewelry or scrap:

Look for a hallmark. A clean 585, 750, or 916 is a strong positive sign.
Run a magnet test. Thirty seconds, rules out the worst fakes.
If the item is large enough, do the density test. Accept up to ~10% error.
For anything meaningful, finish with either the acid test or a trip to a jeweler's XRF machine.

Once you are confident the item is real, use the gold calculator to estimate its melt value and benchmark any offer you get against that number.