How to Test If Gold Is Real

Simple checks you can do at home

If you want to test if gold is real, start with the basics. Check for a hallmark (that’s the small official stamp showing metal type and purity); it might read 999, 18K, 14K or something similar. Treat any hallmark as a clue, not a guarantee, fake stamps exist and some older jewelry was never marked.

You can calculate density by weighing and measuring your item. Gold is heavier than just about anything else you’ll find in jewelry: 19.3 grams per cubic centimeter. If your measurements do not match that, allowing for stones, settings or hollow space, something is off. But this only works if your scale and ruler are accurate.

Some people try a magnet. Gold itself will never stick, but neither will plenty of other metals, so it does not prove much. Use it to spot (for example) iron or basic steel, but nothing more. Combine several methods before you decide.

Professional methods: acid, XRF and ultrasound

• Acid test: The tester makes a tiny scratch and applies nitric acid with a strict concentration. The result shows if the item resists or reacts, giving a rough estimate of karat. Acid may leave a visible mark, especially on softer alloys or thin plating.
• XRF (X-ray fluorescence): This non-invasive machine reads the elements present by measuring fluorescence from the surface layer of metal. Because it only scans the outermost microns, it may be fooled by layered or plated counterfeits.
• Ultrasound: The instrument sends a pulse through the gold, measuring thickness and structure. It’s often used on bars to check for a tungsten core hidden inside gold.
• Electrical conductivity: Each purity grade of gold lets electricity flow with a characteristic resistance. The reading shifts if other metals are present, but the device has to be properly calibrated every time.

No single method tells the full story, so dealers combine them. For definitions of karats and what those grades mean in practice, see gold purity, karats and hallmarks.

Why tungsten-filled bars fool simple tests

Tungsten’s density is almost identical to gold’s (19.25 grams per cubic centimeter), so a bar that is mostly tungsten but coated in gold can pass a basic density measurement. You won’t spot it with a magnet, either. But ultrasound or drilling for an assay sample reveals the difference at once.

Because one test may miss a sophisticated fake, most gold dealers and refiners use several methods for every trade. Fire assay is standard at labs, this involves melting a small scraped sample for a result accurate down to a fraction of a percent. You’ll find more about how certified assays and bar types work in our cast vs minted gold bars article.

Since gold prices move a lot, an item suspected of being a fake usually becomes hard to sell or use as collateral. If you are ever unsure, ask for an accredited assayer’s report or buy and sell only through established precious metals dealers.

Frequently asked questions