How to Check Gold Purity Before You Buy (and Myths to Ignore)
Karat stamps, karat-meter (XRF) tests, acid tests and the magnet myth — practical ways to check whether your gold is really 22K or 21K before you pay.
The price of gold depends on its purity, so a piece sold as 22K that is really 20K costs you money twice: once when you buy and again when you sell. Here are the checks that work — and a few that don't.
1. Read the stamp — but don't rely on it alone
Most jewellery carries a small stamp such as 916 (22K), 875 (21K) or 750 (18K). In India, hallmarking by the Bureau of Indian Standards with a unique HUID code is compulsory for most jewellery. In Pakistan there is no single compulsory national hallmark, so a stamp is the jeweller's claim rather than independent certification. It is a useful starting point, not proof.
2. Get a karat-meter (XRF) test
Most Sarafa bazaars have shops with an X-ray fluorescence (XRF) karat meter. The test takes about a minute, does not damage the piece and prints the percentage of gold and other metals. It is the most practical check for buyers and sellers, and it usually costs only a small fee. Limitations: XRF reads the surface, so heavily plated or hollow items filled with another material can fool it.
3. Acid (touchstone) test
The traditional method: the item is rubbed on a black touchstone and the streak is tested with acids of different strengths. Experienced testers are accurate to about one karat. It leaves a faint mark on the piece, so it is better suited to scrap and old gold than to new jewellery.
4. Fire assay
Melting a sample and separating the gold is the most accurate method, but it destroys the sample and is used by refiners and for bars, not for your jewellery.
Myths to ignore
- "Gold isn't magnetic, so the magnet test proves it's real." Gold isn't magnetic, but neither are brass, copper or many fake alloys. A magnet can only catch obvious steel fakes.
- "Bite it." Soft teeth marks tell you nothing reliable and can damage the piece.
- "Real gold doesn't change colour." Lower-karat gold can tarnish slightly because of its copper and silver content; that does not make it fake.
A simple routine when buying
- Ask for the karat and weight in grams to be written on the receipt.
- Check the weight on the shop's digital scale yourself.
- For large purchases, pay a few hundred rupees for an independent XRF test at a nearby shop.
- Price the piece using today's rate for that karat — 22K is Rs 374,360 per tola today — plus the agreed making charge.
Our gold calculator accepts a custom purity percentage, so you can value a piece using exactly the result the karat meter gives you.
Rates are indicative and for information only — not financial advice. Confirm prices with your jeweller before buying or selling.
