A page for each mark people actually find — 925, 750, 585, 375, PLAT, GP, 800 — with what it guarantees, what it does not, and how to check the metal agrees with it.
7 hallmarks15 modelsFree · no account
Take a ring off and look inside the shank. Almost every piece of precious-metal jewellery carries a mark there, and almost nobody knows how to read it. That is a shame, because the mark is the single most informative thing about the object: it states the metal, it often states the country, and on British work it states the year and the office that tested it.
The important thing to understand first is what kind of statement a mark is. In the United Kingdom, hallmarking is compulsory by law and has been for seven centuries: an independent assay office tested the metal and struck the mark, and forging that mark is a specific criminal offence. In the United States there are no assay offices at all — a stamp is the manufacturer's own claim, legally binding under the National Stamping Act but verified by nobody.
So the pages here do two things. They decode the mark, which is the easy part. And then they set out how to check whether the metal underneath behaves the way the mark says it should — because a stamp costs a fraction of a penny to apply, and the commonest fraud in jewellery is not a false number but a true number with two small letters after it.
The order matters. Most of what goes wrong happens in step one, because the letters that change the meaning are smaller than the number that does not.
Use a 10× loupe and follow the stamp from end to end. The fineness number is the part everybody reads; the part that changes everything is what surrounds it. GP, GEP, EP, HGE and RGP all mean plated. GF and a fraction like 1/20 mean gold filled. 'Over sterling' means the base is silver. These characters are smaller than the number and wear first.
A lone fineness number is the weakest form of mark. A British piece should also carry a sponsor's mark and an assay office mark — leopard's head, anchor, rose or castle — which means an independent body tested it. German silver from 1888 carries a crescent and crown. A maker's trademark on American work at least puts a reputation behind the claim.
This is the most reliable free test on any worn piece. Look at the underside of the shank, the inside of a bangle, the back of a clasp, the crests of a texture. Plating fails there first, and what shows through is a different colour: yellow-pink for brass, grey-white for nickel, bright silver-white for a sterling base. Solid metal wears to more of the same metal.
Precious metals are dense — platinum about 21.4, gold 19.3 pure, silver 10.5, against brass at 8.5. A solid piece feels wrong for its size and a plated one does not. When the value warrants certainty, an acid test takes a jeweller a minute and XRF reads the actual composition without touching the surface. Under-karating is invisible to every other check.
One page each, in the hallmark's own terms — its code system, its weighted checks, its models and what they do on the secondary market.
Lovenhall RingThe mark tells you what the metal claims to be. The instrument reads the setting and the stones together and gives a range to orient you — before anyone charges you for an appraisal.