How to Check Gold Purity — BIS Hallmark Guide
Your definitive guide to understanding gold karat, BIS hallmarking & purity testing in India
Gold has been the cornerstone of Indian culture, wealth, and adornment for thousands of years. Whether you are purchasing a gold necklace, a pair of bangles, or investing in gold coins, understanding gold purity is essential. With rising gold prices in 2026, knowing how to verify what you are paying for protects your investment and ensures you receive genuine value.
At Londe Jewellers, every piece of gold jewellery we sell is BIS hallmarked and verified for purity. This guide explains everything you need to know about the karat system, BIS hallmarking, and how to check gold purity before you buy.
What is Gold Purity?
Pure gold, also called 24 karat gold, is too soft for everyday jewellery. To make it durable enough for rings, chains, and bangles, gold is alloyed with other metals such as copper, silver, or zinc. The proportion of pure gold in the alloy determines its karat value. Higher karat means more pure gold content, but also softer metal. Lower karat means greater durability but less gold content.
In India, 22 karat gold is the most popular choice for traditional jewellery because it offers an ideal balance between purity and strength. For diamond-studded or intricate designs, 18 karat and 14 karat gold are preferred because they hold gemstones more securely.
Gold Karat Comparison Table
The table below breaks down the most common gold purities available in Indian jewellery stores. Check today's live gold rate in Nagpur to calculate the per-gram price for each karat.
| Karat | Gold Purity (%) | Fineness | Parts Gold (out of 24) | Common Use | Durability |
|---|---|---|---|---|---|
| 24K | 99.9% | 999 | 24/24 | Gold coins, bars, investment | Very soft |
| 22K | 91.6% | 916 | 22/24 | Traditional jewellery, chains, bangles | Soft but wearable |
| 18K | 75.0% | 750 | 18/24 | Diamond jewellery, rings, modern designs | Moderately durable |
| 14K | 58.3% | 585 | 14/24 | Everyday wear, studded jewellery | Highly durable |
What is BIS Hallmark?
BIS stands for the Bureau of Indian Standards. Since June 2021, it is mandatory for all gold jewellery sold in India to carry a BIS hallmark under the Hallmarking of Gold Jewellery and Gold Artefacts Order. This hallmark is a government-backed guarantee that the gold purity stated by the jeweller is accurate and verified by an independent assaying centre.
The BIS hallmark system was introduced to protect consumers from being cheated by unscrupulous sellers who mix lower-grade gold or add excessive alloys. When you buy hallmarked gold from Londe Jewellers stores in Nagpur, you can be confident that every gram meets the stated purity.
How to Read a BIS Hallmark (HUID System)
Since July 2021, BIS introduced the HUID (Hallmark Unique Identification) system. Every hallmarked piece of gold jewellery now receives a unique six-digit alphanumeric code. Here is how the new hallmark looks:
| Symbol/Mark | Meaning | Example |
|---|---|---|
| BIS Logo | Certified by Bureau of Indian Standards | Triangle with BIS mark |
| Purity Grade | Karat and fineness of gold | 22K916, 18K750, 14K585 |
| HUID Number | 6-digit unique ID traceable on BIS website | AB12CD |
You can verify any HUID code on the official BIS Care app or website. Simply enter the six-character code and it will show you the jeweller name, assaying centre, purity grade, and date of hallmarking. This makes it virtually impossible to counterfeit hallmarked jewellery.
Methods to Check Gold Purity
Beyond the BIS hallmark, there are several ways to verify gold purity. Some are professional techniques used by assaying centres, while others can be done at home as preliminary checks.
| Method | Accuracy | Destructive? | Where Available |
|---|---|---|---|
| XRF (X-Ray Fluorescence) | Very high (99%+) | No | BIS assaying centres, leading jewellers |
| Fire Assay (Cupellation) | Highest (gold standard) | Yes (small sample) | BIS assaying centres |
| Acid Test (Touchstone) | Moderate | Slightly (surface scratch) | Traditional jewellers |
| Electronic Gold Tester | Good | No | Jewellery shops |
| Magnet Test | Low (only detects fakes) | No | Home |
| Density/Water Test | Moderate | No | Home |
At Londe Jewellers, we use XRF testing equipment in our stores so customers can verify the purity of their purchase on the spot. Combined with BIS hallmarking, this gives you double assurance of gold quality.
Why BIS Hallmark Matters for Your Purchase
Buying non-hallmarked gold jewellery carries significant risks. Without hallmarking, you have no independent verification that the gold is actually the purity claimed by the seller. Here is what could go wrong:
- Lower purity than claimed: A piece sold as 22K could actually be 20K or 18K, meaning you pay more per gram of pure gold than you should.
- Poor resale value: When you try to sell or exchange non-hallmarked gold, buyers will offer significantly lower rates because they cannot verify purity without testing.
- No legal recourse: Without hallmark documentation, it is difficult to file complaints or claim refunds for impure gold.
- Cadmium contamination: Some non-hallmarked gold may contain cadmium, a toxic metal that can cause skin reactions.
When you shop at Londe Jewellers' gold collection, every item carries proper BIS hallmarking with a traceable HUID number, along with a detailed invoice showing gross weight, net weight, making charges, and purity grade.
Tips for Buying Gold Jewellery in Nagpur
- Always check the hallmark: Look for the BIS logo, purity mark, and HUID on every piece.
- Verify the HUID online: Use the BIS Care app to confirm authenticity before leaving the store.
- Compare gold rates: Check the daily gold rate before visiting to know the fair price per gram.
- Ask for a detailed invoice: Ensure the bill lists gross weight, net weight, stone weight (if any), making charges, and GST separately.
- Understand making charges: Making charges vary by design complexity. Machine-made pieces have lower charges than handcrafted ones.
- Check the buyback policy: Reputable jewellers like Londe offer full gold-value buyback on hallmarked jewellery purchased from them.
- Consider Gold SIP: If you want to accumulate gold over time, explore our Gold SIP monthly plan for systematic savings.