925 sterling silver is an alloy that is 92.5% silver by weight, the rest usually copper, and a great deal of genuine 925 jewelry is made in China. But a “925” stamp is only the maker’s claim, and home checks such as a magnet or an acid drop can only rule pieces out. The reliable tests are XRF analysis, which reads the metal’s make-up without damaging the piece, and a chemical assay at a laboratory, which uses up a small sample and gives the most precise answer. For an order, ask for a third-party lab report on pieces from that order, naming the laboratory, the piece tested, the date and a report number.
What sterling silver is
Pure silver is too soft for rings, clasps and anything worn daily. Sterling silver is 925 parts per thousand silver, with the rest another metal — almost always copper, which makes it harder. The copper is also why sterling tarnishes. UK law defines the sterling standard as 925 (Hallmarking Act 1973); “S925” on a Chinese listing is the same claim.
What buyers run into is not the alloy but pieces sold as 925 that are not, or only partly are. Forum posts describe clasps stamped 925 that a magnet picks up, chains that turn out to be plated base metal, and earrings where only the post is silver.
Stamps and marks: what they do and don’t prove
United States
The National Gold and Silver Stamping Act, 15 U.S.C. §294–297, says:
- §294: a manufacturer or dealer may not import, export, mail or ship between states silver articles marked as finer than they are.
- §296: an article may be marked “sterling” or “sterling silver” only if it contains 925 one-thousandth parts pure silver. Tested without the solder, a shortfall of 4 parts per thousand is allowed; assayed whole, solder included, a slightly larger shortfall is allowed. The article must pass both tests.
- §297: base metal plated with gold or silver — silver-plated brass, for example — may not be stamped “sterling” or “coin”; plated sterling silver still may. And a manufacturer or dealer that puts a quality mark such as 925 on jewelry sold to consumers, or an importer of jewelry bearing one, must also apply its own trademark (registered, or applied for, in the US) or its name — by the same method, in letters at least as large, as close as possible to the mark. For your brand, that means your mark beside the 925.
There is no official US assay of jewelry: a 925 stamp is the maker’s own claim, and the law makes a false one unlawful. A 925 with no trademark or name beside it is already a warning sign for goods sold in the US. The FTC’s Jewelry Guides (16 CFR 23.5) add that “sterling” and “solid silver” are for products at least 925 thousandths pure silver, and that a product only coated with silver must say so.
United Kingdom and EU
In the UK, silver articles with a total metal weight of 7.78 g or more must bear approved hallmarks — struck by a UK assay office (including its offices abroad) or a recognised convention hallmark — before they can be described as silver when sold (Hallmarking Act 1973, Schedule 1). Pieces that combine silver with gold or other materials can need a hallmark below that weight; an assay office can tell you. Unlike a maker’s stamp, a hallmark means the metal was tested independently; plan time for it and room on the piece. In the EU, hallmarking is set country by country.
Quick checks and their limits
| Check | What it can tell you | What it cannot |
|---|---|---|
| Stamp and maker’s mark | That someone claims it is sterling | Whether that is true, or whether every part is silver |
| Magnet | A strong pull means iron or steel — not sterling | Copper and brass are not magnetic either |
| Price against weight | A price below the silver value cannot be sterling | Anything once the price is plausible |
| Acid test on a scratch | How the metal at that spot reacts | What is under the surface; it also marks the piece |
Silver is not magnetic, so a piece a magnet grabs is not sterling — but one that ignores the magnet may still be brass.
Plated pieces are what fool quick tests. A brass ring with a silver coating looks, polishes and reacts at the surface like silver; you reach the base metal only by filing through the plating. The reverse also happens: genuine sterling plated with rhodium or gold will not react like silver on the surface. Quick checks catch obvious fakes. They cannot clear an order.
Reliable tests
XRF (X-ray fluorescence). An analyser aims X-rays at the piece and reads which elements are present, and in what share — silver and copper, and also nickel, lead or cadmium. It is fast and leaves no mark. It reads only the outer layer of metal, so plating distorts the result: a lab tests an unplated spot, such as the inside of a band, or measures the plating separately. XRF is also the usual way to measure plating thickness.
Chemical assay. The lab dissolves a small cut or scraping — for silver usually by titration, or by the traditional fire assay. It destroys a little metal and takes longer, but it is the most precise answer, and the one to use when an XRF result is borderline or disputed.
A lab report you can rely on names the laboratory (and whether it is accredited for that test), exactly what was tested — design and part, ideally with photos — the date, a report number you can check with the lab, the method, and the result for each element. It covers the pieces tested, not the next batch, and one made on pieces drawn from your own order says more than one on a sample the supplier chose.
Plated silver or plated base metal
- 925 silver with rhodium, gold or vermeil on top: silver all the way through; if the plating wears, silver shows. In the US, gold vermeil means gold of 10 karat or more, at least 2.5 microns thick (FTC) — see what vermeil means.
- Brass or copper plated with silver or gold: base metal inside; as the plating wears, yellow or red shows. It cannot be stamped sterling.
Many genuine pieces include a few non-silver parts, such as the steel spring inside a clasp. That is normal, but you should be told, so you can describe the product accurately.
Nickel
Sterling silver itself normally contains no nickel; when nickel turns up, it usually comes from findings, solder or a layer under gold plating. The EU limits how much nickel a piece releases, not how much it contains (REACH, Annex XVII, entry 27): at most 0.5 µg/cm²/week for items in direct and prolonged contact with the skin, and less than 0.2 µg/cm²/week for posts inserted into pierced ears or other pierced parts of the body. Conformity is shown with test methods adopted by CEN, the European standards body; the release test is EN 1811. XRF can show that nickel is present, but only a release test shows whether a piece meets the limit. For plated pieces the limit must still hold after a period of normal wear, so the release test follows a wear simulation (EN 12472).
What to ask your supplier
- Are all silver parts 925, including clasps, ear posts, jump rings and settings? Which parts are not silver?
- What is the plating, how thick, and is there a nickel layer underneath?
- Can pieces from my order — not a separate sample — go to a third-party lab, and who pays?
- Can my trademark or name go next to the 925 stamp?
- What is the silver weight of each piece, and does the price make sense for it?
- What happens if a test shows a part is not 925?
What we do
The silver parts of every Asoran piece are 925 sterling silver, and any part that is not silver, such as a clasp spring, is listed on your quote. If you need proof, we send pieces from your order to an accredited third-party laboratory for a silver or nickel test, at cost. Silver parts that testing shows are not 925 count as a fault you can claim for up to 6 months after delivery — see our returns and claims policy.
Sources
- 15 U.S.C. §294, §296 and §297 — National Gold and Silver Stamping Act
- 16 CFR 23.5 — FTC Jewelry Guides, silver content
- UK Hallmarking Act 1973, Schedule 1 — legislation.gov.uk
- REACH Regulation, Annex XVII, entry 27 — EUR-Lex