Three small digits stamped inside a ring or on the back of a clasp. Here's what 925 means, what the other numbers you'll see mean, who is allowed to stamp them, and how much a stamp can actually tell you.
Turn over most silver jewellery and somewhere there's a tiny mark: inside the band of a ring, on the tag next to a clasp, on the back of a pendant. Very often it says 925.
It's one of the most useful marks in jewellery, and one of the most misunderstood.
The short answer
925 means sterling silver: 925 parts of pure silver in every 1,000. The other 75 parts are another metal, almost always copper.
The copper is there on purpose. Pure silver is beautiful but soft. A ring made from it would scratch easily and slowly lose its shape. A small amount of copper makes the metal hard enough to carve, set stones into and wear every day, while keeping the colour and shine of silver.
The standard is very old. In England, a statute of 1300 under Edward I required silver goods to meet the sterling standard, and wardens tested them and struck the ones that passed with a leopard's head. More than seven centuries later, 925 still means the same thing.
The other numbers you'll see
- 999 or "fine silver": 99.9% silver. Used for bullion and some soft, simple jewellery.
- 958 or Britannia silver: 95.8% silver. A higher British standard, softer than sterling.
- 925, "sterling", "ster" or "S925": 92.5% silver. The standard for most fine silver jewellery.
- 900: 90% silver. Often called coin silver, from old American and European coinage.
- 835 or 800: 83.5% or 80% silver. Common on older continental European pieces.
And a few marks that sound like silver but mean something else:
- EPNS: electroplated nickel silver. A thin silver coating over a base metal.
- Nickel silver or German silver: a copper, nickel and zinc alloy. Despite the name, there's no silver in it at all.
- "Silver plated" or "silver tone": a coating or a colour, not the metal.
- "Tibetan silver": a trade name with no legal meaning, usually a base-metal alloy. We wrote a whole piece on it: What Is Tibetan Silver?
Who puts the stamp there
This is the part most people don't know, and it changes what a stamp means.
In the United Kingdom, silver weighing 7.78 grams or more must be tested by one of the independent assay offices and hallmarked before it can be sold as silver. A full hallmark includes the maker's mark, the fineness and the mark of the assay office that tested it. That's an independent guarantee.
In the United States, there's no independent testing. The maker or seller applies the mark. Under the National Gold and Silver Stamping Act, anyone who stamps a quality mark like "sterling" or "925" must also stamp a registered trademark, so the claim can be traced back to whoever made it.
In most other places, including much of Asia, the stamp is the maker's own claim and nothing more.
So a 925 stamp is only as good as the person who struck it. That's true whoever you buy from, including us. A hallmark from an assay office means more than a maker's stamp, and a maker who will tell you plainly, in writing, what the metal is means more than one who won't.
How to check a piece that says 925
- Magnet. Silver isn't magnetic. If a strong magnet grabs the piece, it isn't sterling. If it doesn't, that proves less, because many base alloys aren't magnetic either.
- Price against weight. Silver has a market price. A large, heavy piece sold for a few dollars can't be solid sterling.
- Wear. Sterling darkens over time and polishes back to white. Plated pieces wear through at the edges, and a yellowish or pinkish metal starts to show.
- A jeweller. An acid test takes minutes. Many jewellers also have an X-ray fluorescence gun that reads the alloy without marking the piece.
Common questions about 925 silver
Does 925 silver tarnish? Yes. The silver reacts slowly with sulphur in the air and forms a dark film. It isn't damage, and it polishes off. On carved pieces some of that dark is left on purpose, which is why the cleaning advice is different. See How to Clean Sterling Silver Jewelry and Oxidized Silver.
Will 925 silver turn my finger green? Occasionally sterling leaves a faint dark or greenish mark, from the copper reacting with sweat, lotion or skin chemistry. It washes off and isn't harmful. Base-metal "silver" does it far more often.
Is sterling silver good for sensitive skin? Most people wear sterling without any problem. The usual culprit for metal allergies is nickel, which is common in cheap white-metal alloys. If you know you react to nickel, ask the seller what the other 7.5% is.
Is 925 the same as "real silver"? For jewellery, yes. Sterling is real silver. It's simply the alloy that makes silver strong enough to wear.
What we use
Everything we carve is S925 sterling silver. Where there's gold, it's 24K and fire-gilded, not plated. Where there are stones, they're set by hand into carving that's already finished. If you ever want to know exactly what's in a piece, ask us and we'll tell you in writing.
Three digits can tell you what a piece is meant to be. Only the person who stamped them can tell you whether it is.
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More from the Journal: What Is Tibetan Silver? · Gold Vermeil vs Gold Plated · Hand-Carved Silver: Five Ways to Tell