925 on jewellery means the piece is sterling silver: 92.5% pure silver mixed with 7.5% other metals, usually copper, to make it strong enough to wear. In the UK, silver items over 7.78 grams sold as silver must also carry an official hallmark from an assay office.
Why silver is mixed with copper
Pure silver (99.9%) is too soft for rings, chains and hardware. Adding a small amount of copper makes it hard enough to hold its shape and keep detail, which is why sterling silver is the standard for fine silver jewellery and for brands such as Chrome Hearts.
Common silver marks
| Mark | Meaning | Silver content |
|---|---|---|
| 999 | Fine silver | 99.9% |
| 958 | Britannia silver | 95.84% |
| 925 | Sterling silver | 92.5% |
| 800 | Continental silver, common on older European pieces | 80% |
| EPNS, "silver plated" | Base metal with a thin silver coating | Very little |
UK hallmarks explained
Under the Hallmarking Act 1973, silver over 7.78 grams sold in the UK as silver must be independently tested and hallmarked by one of four assay offices. A full UK hallmark has three compulsory parts:
- Sponsor's mark: the initials of the maker or importer.
- Fineness mark: the purity, for example 925.
- Assay office mark: a leopard's head for London, an anchor for Birmingham, a rose for Sheffield, or a castle for Edinburgh.
A date letter is optional. Imported designer silver may carry its own stamps, such as .925 with a brand mark, and may also be hallmarked if it is sold as silver in the UK.
Chrome Hearts silver and .925
Chrome Hearts silver is stamped .925, usually alongside "CH" and a copyright mark. A crisp, level stamp is one of the checks in our guide to spotting fake Chrome Hearts.
How to tell if silver is real at home
- Look for the stamp with a loupe or phone zoom.
- Magnet test: silver is not magnetic. If a magnet sticks, the piece is not solid silver. Passing does not prove it is silver, though.
- Feel and weight: sterling feels dense and cool to the touch.
- Tarnish: real silver darkens over time, especially in recesses.
For anything valuable, ask a jeweller or assay office to test it.
Caring for sterling silver
- Store pieces separately in a dry pouch to slow tarnish.
- Polish with a silver cloth. Avoid dips on oxidised designer pieces, because they strip the dark detail that is meant to be there.
- Take silver off before swimming, as chlorine attacks it.
Browse authenticated jewellery at GEMLUX.
FAQ
Is 925 silver real silver?
Yes. 925 is sterling silver, 92.5% pure silver.
Does 925 silver tarnish?
Yes, because of the copper content. Tarnish can be polished off, and wearing silver often slows it down.
Can 925 silver be gold plated?
Yes. Silver gilt, also called vermeil, is 925 silver with a gold layer. It is still stamped 925.
Is 925 the same as 18k?
No. 925 refers to silver purity. 18k refers to gold that is 75% pure.