916 Gold, KDM and HUID Hallmark Explained: What to Check on Every Piece
916 gold is 22 carat gold: 91.6% pure gold, with the rest made up of metals such as silver and copper that make it strong enough for jewellery. The number 916 is simply the purity in parts per thousand. Today (9 November 2026) 916 gold in Chennai costs ₹13,160 per gram.
What the BIS hallmark looks like
Since hallmarking became mandatory in 2021, a hallmarked piece carries three marks:
- The BIS standard mark — the triangle-shaped logo of the Bureau of Indian Standards.
- Purity and fineness — for example 22K916 (22 carat), 18K750 (18 carat) or 14K585 (14 carat).
- HUID — a 6-character alphanumeric Hallmark Unique Identification code, different for every piece. It is mandatory on hallmarked jewellery sold from 1 April 2023.
Jewellery weighing less than 2 grams is exempt from mandatory hallmarking.
How to verify the HUID
Install the official BIS CARE app and use "Verify HUID". It shows the type of article, its purity, and the jeweller and hallmarking centre that tested it. If the details do not match what you are buying, ask the jeweller before paying. See also how to check gold purity.
What is KDM gold?
KDM refers to jewellery soldered with a cadmium alloy. Cadmium let jewellers solder 22K pieces without lowering the purity much, but its fumes are toxic to the workers who use it. BIS does not allow cadmium solder in hallmarked jewellery, so "KDM" is no longer a mark of quality — the BIS hallmark with HUID is what proves purity today.
Is my old jewellery without HUID still valid?
Yes. You can wear, sell or exchange older jewellery that has no HUID or carries the older hallmark. Jewellers test it before buying it back; you can also get it hallmarked through a jeweller.
Frequently asked questions
What does 916 mean on gold?
916 means the gold is 91.6% pure, which is 22 carat. Today (9 November 2026) 916 gold in Chennai costs ₹13,160 per gram.
What is HUID on gold jewellery?
HUID (Hallmark Unique Identification) is a 6-character alphanumeric code stamped on each hallmarked piece. You can verify it in the BIS CARE app. It has been mandatory on hallmarked jewellery since 1 April 2023.
Is KDM gold better than 916 gold?
No. KDM only means cadmium solder was used, which BIS does not allow in hallmarked jewellery. Purity is proven by the BIS hallmark (for example 22K916) and the HUID.