Reading a Hallmark: What the Small Stamps Mean
The tiny marks inside a ring record what the metal is and, in some countries, who tested it. They are the first thing to check.
What a hallmark is
A hallmark is an official mark struck on precious metal to certify its content. Systems differ by country: some require independent testing, others rely on the maker's own stamp.
Fineness numbers
Fineness is purity in parts per thousand. 925 means 92.5 per cent silver. 750 is 18-carat gold, 585 is 14-carat.
Other marks you may see
- A maker's or sponsor's mark.
- An assay office symbol, where testing is compulsory.
- A date letter on some older pieces.
What a stamp does not prove
A number alone can be faked. In countries without compulsory testing, buy from sellers who will put the metal content on the receipt.
Plated is not solid
Marks such as "GP" or "plated" mean a thin layer over base metal. That is fine if priced accordingly.
When in doubt
A jeweller can test metal quickly. For anything expensive, ask before you buy, not after.
Reviewed 2026-10-14