KDM Gold Means: How to Spot Authentic Jewellery vs Counterfeits
KDM Gold Means: How to Spot Authentic Jewellery vs Counterfeits
KDM gold means jewellery joined with cadmium solder, but the 'KDM' stamp itself was never registered or verified, which makes it one of the easiest marks to fake. Counterfeits fall into five patterns: gold-plated base metal, lower-karat gold stamped 916, fake BIS logos or HUIDs, weight padded with lac or wire cores, and rolled gold sold as solid. Check the marks, verify any HUID in the BIS CARE app, and confirm purity with a non-destructive XRF test before you pay or sell.
A three-letter punch costs a few hundred rupees in any metalworking market. That is the uncomfortable truth behind the word KDM. Because the stamp was never tied to a registry, a licence or a testing centre, anyone could press it into anything. Most KDM-marked jewellery in Bengali households is genuine gold. However, the stamp that reassures families is the same one counterfeiters rely on.
This guide focuses on marks and construction: how to read what is stamped on a piece, how fakes imitate it, and where visual checks end and testing has to begin. For kitchen-table checks such as the magnet and water tests, see our separate guide.
Home checks: how to tell if gold is real at home →
Why the KDM Mark Is So Easy to Counterfeit
An authentic BIS hallmark is applied by a licensed Assaying and Hallmarking Centre after the metal has been tested. A KDM stamp was applied by whoever made or sold the piece, with no test required. So a KDM mark on its own proves only that someone owned a KDM punch. It is a claim, not evidence, and it should be weighed like any other unverified claim.
The Five Counterfeit Patterns to Know
1. Plated base metal stamped "KDM" or "916 KDM"
Brass or copper with a thin gold layer, stamped to look like an old 22K piece. These most often turn up as "grandmother's jewellery" offered privately, or as cheap lots at fairs. The giveaway is wear: at edges, clasps and the inside of rings, a pinkish or greyish metal starts to show through.
2. Lower-karat gold stamped as 22K
This is the most common and hardest to catch. The piece is real gold, but 18K to 20K rather than the 91.6% the stamp suggests. It looks right, feels right and passes a magnet. Only a purity measurement exposes it. On a 20-gram piece, the difference between 91.6% and 83% is more than ₹25,000 at 2026 rates.
3. Fake BIS triangle or invented HUID
Counterfeiters now copy the modern hallmark, adding a BIS-style triangle and a six-character code to make a piece look post-2021. The code will either not exist or will belong to a different article when you look it up.
4. Weight padded with lac, wax or wire cores
Hollow bangles and bala filled with lac are a legitimate Bengali tradition. The lac gives strength. It becomes a counterfeit when the filling is sold as gold weight, or when a base-metal wire core is hidden inside a thin gold tube. A piece that feels solid can contain surprisingly little gold.
5. Rolled gold or gold-filled sold as solid
Rolled gold has a thicker gold layer bonded over base metal. It wears far better than plating and can fool people for years, which is why it sometimes surfaces at resale as "old KDM".
Reading the Marks: What Authentic Looks Like in Each Era
| Era | What you usually see | What it proves | Red flags |
|---|---|---|---|
| KDM era (c. 1985–2015) | "KDM", "916 KDM", "22K" or a shop code, hand-punched | Nothing independently verified | Crisp laser-engraved "KDM" on a piece claimed to be decades old |
| Early BIS hallmark (2000–2021) | BIS logo, fineness such as 916, testing centre mark, jeweller's mark; some carry a year letter | Tested at a licensed centre | Only a BIS logo with no fineness or centre mark |
| Current hallmark (2021 onwards) | BIS logo, purity such as 22K916, six-character HUID | Tested and traceable to one article | HUID missing, not found, or matching a different article type |
A mark from the wrong era is more suspicious than a missing mark. A decades-old ornament with no stamp is normal. A new-looking piece stamped 'KDM', or an 'old' piece with a modern HUID that does not match, deserves a closer look.
How to Verify a HUID in Two Minutes
- Install the official BIS CARE app on your phone.
- Open the 'Verify HUID' option and enter the six-character code exactly as engraved.
- Compare the result with the piece in your hand: article type (ring, chain, bangle), declared purity, and the jeweller and hallmarking centre registered to it.
- If the code returns nothing, or describes a different article, do not buy the piece until it has been tested independently.
HUID verification only applies to jewellery hallmarked under the current system. KDM-era ornaments will not have one, and that is not in itself a problem. For those pieces, the only answer is to test the metal.
Deeper dive: 916 and HUID explained →
Where Visual Checks Stop and Testing Starts
Marks, colour and wear can help you spot an obvious fake. They cannot tell 20K from 22K, and they cannot see what is inside a hollow bangle. For that you need a measurement. The acid test marks or damages the piece, and fire assay destroys a sample. An XRF spectrometer reads the metal composition in about a minute without leaving a mark. The result gives the percentage of gold, silver, copper, zinc and any other metal present.
| Check | Catches plated fakes | Catches under-karat gold | Damages the piece |
|---|---|---|---|
| Reading the stamp | Sometimes | No | No |
| HUID lookup | Only on post-2021 pieces | Only on post-2021 pieces | No |
| Home tests (magnet, water) | Often | No | No |
| Acid / touchstone | Yes | Roughly | Yes, marks the surface |
| XRF spectrometer | Yes | Yes, to fractions of a percent | No |
Where Counterfeit KDM Pieces Tend to Surface Around Durgapur
In our experience testing gold for families across the region, doubtful pieces rarely come from established shops. They come from private sales between acquaintances, lots bought at fairs, pledged-jewellery auctions, and ornaments that changed hands many times before reaching the current owner. If you are buying second-hand gold anywhere from Asansol and Raniganj to Panagarh, Budbud or Bankura, get it tested before money changes hands, not after.
Get a Free Authenticity Check at Auriksha
Walk in to our City Centre office in Durgapur with any KDM, hallmarked or unmarked piece. We test it on our German XRF spectrometer in front of you and show the full composition on screen. There is no charge and no obligation to sell. If the piece is genuine and you do decide to sell, we pay the live rate on measured purity and net weight, less our fixed 2% margin and 1% dust-and-wax deduction.
Read next: How KDM should shape your purchasing decisions →
Read: 10 facts about what KDM gold means for jewellers →
Read: How to check gold purity at home in Durgapur →
Gold buyer for Asansol customers →