Silver purity in India is checked first by XRF screening, which reads the metal content in seconds, and then confirmed where needed by a chemical assay, which dissolves a small sample and measures the silver precisely. Hallmarking is managed by the Bureau of Indian Standards (BIS) through recognised assaying and hallmarking centres.
The rules on which silver articles must be hallmarked have changed over time, so check the current BIS rules before you rely on a mark or its absence.
How purity is tested
- XRF screening: non-destructive and fast. Good for checking lots, but it reads the surface, so plating can distort the result.
- Fire or chemical assay: a small scraping is dissolved and the silver measured. Accurate and used for hallmarking and disputes.
- Touchstone and acid tests: quick trade checks that indicate silver content, but they are not precise.
What a BIS hallmark shows
A BIS hallmark normally includes the BIS mark, the purity grade, and marks that identify the assaying centre and the jeweller. The grades and the exact marks are set out in the BIS standard for silver. A hallmark tells you the item was tested at a recognised centre and met the grade stamped on it.
Because rules and mark formats are revised, ask the supplier which centre hallmarked the goods and verify current requirements with BIS.
Checks a buyer can run
- Ask for the hallmarking centre's details and the purity grade on each design.
- Screen a sample of pieces by XRF on unplated areas, such as inside a ring band.
- For new suppliers or large orders, send a sample to an independent lab for assay.
- Weigh pieces against the approved sample.
Indian hallmarks abroad
An Indian hallmark does not automatically satisfy the rules in your market. The UK, for example, requires a UK-recognised hallmark on silver articles over its weight threshold, so goods may need marking by a UK assay office. Check the rules in each country you sell in, and allow time for marking in your schedule.
What this means for a buyer
Combine a hallmark with your own screening on each lot, and plan for your market's own marking rules. Our certifications guide covers the wider set of documents to ask for.
Creston & Co works for buyers only, for a fixed fee agreed in writing. We check silver purity on samples in Rajkot, arrange assays at NABL-accredited labs and supervise packing. Ask for a free sourcing review.