How to Check Gold Purity and Hallmark

Buying gold without verifying purity is risky. Here's how to ensure you get what you pay for.

What is BIS Hallmark?

The Bureau of Indian Standards (BIS) hallmark is a certification that gold jewellery meets declared purity. It includes:

BIS mark: The standard certification symbol
Purity in fineness: 916 for 22K, 750 for 18K, 999 for 24K
Assaying centre mark: Which lab certified it
Jeweller's mark: Unique identity of the seller

Understanding Purity Numbers

| Fineness | Karat | Gold % | |----------|-------|--------| | 999 | 24K | 99.9% | | 916 | 22K | 91.6% | | 875 | 21K | 87.5% | | 750 | 18K | 75% |

When you see "916" stamped on a piece, it means 22K gold. This is the most common for Indian jewellery.

How to Verify Hallmark

Look at the piece: Hallmark is usually stamped on the inner side of rings, clasp of chains, or back of pendants. It's small—use a magnifying glass if needed.
Check BIS website: Enter the jeweller's registration number on the BIS portal to verify authenticity.
Ask for invoice: Reputed jewellers provide invoices with purity and weight. Keep them safe.

Red Flags

No hallmark on new jewellery (mandatory for gold jewellery since 2021)
Unusually low price—could mean lower purity or fraud
Jeweller reluctant to provide invoice or certificate

What If My Gold Has No Hallmark?

Older family pieces may predate hallmarking. You can:

Get it tested at a BIS-recognised assaying centre
Use acid testing (done by professionals—not recommended at home)
Take it to a reputed jeweller for verification

Price and Purity

Pure 22K gold should align with market rates. If someone offers "22K" at significantly below gold price in Chennai or your city's rate, be cautious. There may be hidden compromises.