How to Check Gold Purity — 4 Methods Explained

February 2026  |  6 min read  |  IGoldcash Team

Before you sell your gold, understanding its purity is essential — it directly determines how much money you receive. Knowing how gold purity is measured also helps you make sure any buyer is assessing it honestly. Here are four ways to check gold purity, from simple home checks to professional testing methods.

Understanding Gold Purity — Karat and Fineness

KaratFinenessGold ContentCommon Use
24K99999.9%Coins, bars
22K91691.6%Indian jewellery (most common)
18K75075.0%Diamond-set jewellery
14K58558.5%Lightweight modern jewellery

Method 1 — Check the BIS Hallmark

High Reliability

Look for the BIS Hallmark Stamp

The Bureau of Indian Standards (BIS) hallmark is stamped on certified gold jewellery in India. Since 2021, all gold jewellery sold must carry a 6-digit HUID (Hallmark Unique ID) number that can be verified at bis.gov.in.

Look for the BIS triangle logo, the purity mark (916 for 22K, 750 for 18K), and the 6-digit HUID. This is your most reliable starting point for understanding your gold's purity.

Method 2 — The Magnet Test

Basic Check Only

Use a Strong Magnet

Gold is not magnetic. If your jewellery is attracted to a strong magnet, it contains iron or other magnetic metals — a sign it is not pure gold. However, this test only screens for obvious fakes. Many alloys are also non-magnetic, so passing the magnet test does not confirm genuine gold purity.

Use it as a quick first check, nothing more.

Method 3 — The Acid Test

Medium Accuracy — Professional Use

Scratch and Apply Acid

The acid test involves scratching the gold on a black touchstone and applying nitric acid of a known concentration. The colour reaction gives an indication of purity. This is a standard method used by professional gold buyers including IGoldcash.

Important: The acid test involves corrosive chemicals and should only be performed by trained professionals. At IGoldcash, this is done in front of you with full explanation of what the results mean.

When done properly, the acid test gives a reliable purity reading — especially when combined with a second method like the density test.

Method 4 — The Density Test

High Accuracy When Combined

Measure Specific Gravity

Gold has a very specific density — 19.3 g/cm3. The density test measures the specific gravity of your gold by comparing its weight in air versus its weight when submerged in water. The result confirms purity in a way that is entirely non-destructive.

At IGoldcash, we use both the acid test and the density test together. Using two independent methods cross-checks the result and gives a significantly more accurate purity reading than either method alone. This is how we ensure you are paid based on the true value of your gold.

Why Two Tests Matter: A purity reading that is even 1–2% off can mean hundreds or thousands of rupees difference on a 50 gram transaction. Two tests together dramatically reduce that risk of error.

What to Expect When You Visit IGoldcash

When you bring your gold to IGoldcash, both tests are done openly in front of you. We explain what each test shows and answer any questions you have during the process. The weight is measured on a certified scale — also in front of you. Then you receive a written quote showing purity, weight, market rate, and the final offer.

Our customers consistently write detailed reviews not just about the price they received but about how clear and honest the process felt. That transparency is what we take the most pride in.

Get Your Gold Tested for Free

Visit IGoldcash in Dehradun for a free purity assessment — acid test and density test combined — with no obligation to sell.

Call Now WhatsApp Us

Frequently Asked Questions

What does 916 stamped on gold mean?

916 means the gold is 91.6% pure — this is 22 Karat gold, the most common purity for Indian jewellery.

Is the acid test accurate enough?

The acid test is a reliable professional method when done properly. At IGoldcash we combine it with the density test to cross-check the result for maximum accuracy.

Can I watch the purity testing at IGoldcash?

Yes — always. Both the acid test and density test are performed in front of you. We explain each step and you can ask questions throughout.

Can I get my gold tested without selling?

Yes. We offer free purity testing with no obligation to sell. You are welcome to come simply to know what your gold is worth.