What Do the Stamps Inside Your Jewelry Mean?
Take off the ring you're wearing and look inside the band. There's almost certainly something stamped there — two or three characters, maybe a tiny shape, worn soft at the edges. Most people have owned a piece for decades without ever being told what those marks say.
They're worth learning to read, because a few of them mean solid precious metal and a few of the most common ones mean something quite different. We're Chapel Hills Jewelry, a family-owned jeweler on Freeport Road in the Aspinwall area of Pittsburgh, and inherited pieces have been coming across our counter since 1989. This is the explanation we end up giving several times a week.
Where to look
The mark is stamped somewhere the piece isn't seen and isn't worked:
- Rings — inside the shank, usually at the bottom, opposite the stone.
- Chains and bracelets — on the clasp, on the small tag soldered beside it, or on one of the end links.
- Pendants and charms — on the back, or on the bail the chain runs through.
- Earrings — on the post or on the back of the setting.
You will very likely need magnification. A jeweler's loupe is ideal, but a phone camera zoomed all the way in, in good light, reads most marks well enough. Marks on worn pieces are often partly gone; read what's there rather than guessing at what isn't.
Gold: karat marks and fineness numbers
Gold in jewelry is an alloy — pure gold is too soft to hold a stone or survive a lifetime of wear — so the mark tells you how much of the alloy is gold. Two systems say the same thing.
- 10K = 417 — about 41.7% gold
- 14K = 585 — about 58.5% gold
- 18K = 750 — 75% gold
- 22K = 916 — about 91.6% gold
- 24K = 999 — essentially pure gold
The three-digit numbers are parts per thousand and are the common form on European and much modern imported jewelry. American pieces are more often marked in karats, sometimes as 14KT or 14K P — the P indicating a plumb mark, meaning the alloy is at least the stated karat rather than the slight under-karating that older tolerances allowed.
The mark tells you the gold content and nothing else. It says nothing about the colour of the gold, the quality of the workmanship, or the stones. And if you're weighing 14K against 18K for something you're about to buy — a different question entirely — our jeweler has written about choosing between 14K and 18K for a band you'll wear every day, and about why we generally recommend 18KT gold over platinum.
The marks that mean it isn't solid gold
This is the section that matters, and it's where inherited pieces are most often misread.
- GF, or a mark like 1/20 12K GF — gold filled. A layer of gold alloy mechanically bonded to a base-metal core. That fraction is real information: it means the gold layer is one-twentieth of the piece by weight, and that it's 12K gold.
- RGP — rolled gold plate. The same idea with a thinner layer.
- GEP, HGE, GP — gold electroplate, heavy gold electroplate, gold plated. A very thin electroplated layer.
- Vermeil — sterling silver with a gold layer over it. There are minimum thickness and karat requirements for the term, but the body of the piece is silver.
All of these can look exactly like solid gold. A well-made gold-filled piece can wear for a century without giving itself away, and plenty of them are genuinely lovely objects worth keeping and wearing. What they aren't is solid gold, and the gap in metal content between a gold-filled chain and a 14K one is not a small one.
This is where family stories most often come apart, and it's worth being direct about it: if a piece has been described as gold for forty years and the clasp says GF, the clasp is right. That doesn't necessarily make the piece worth less to you. It does change what it is.
One tell you can use yourself: on a plated or filled piece that has seen hard wear, look at the high points — the outside of a bangle, the underside of a ring shank, the edge of a clasp. Base metal showing through as a duller, greyer or coppery colour is a plated layer that has worn away. Solid gold wears thinner; it doesn't change colour underneath.
Platinum, palladium and silver
Platinum is marked PLAT, PT, or with a fineness number: 950 PLAT, PT950, PT900. Platinum jewelry is usually 90% or 95% pure, so the numbers run higher than gold's. It's noticeably heavier than gold of the same size, which is often the first clue.
Palladium appears as PD, PD950 or 950PD — a lighter white metal in the platinum family.
Silver is marked 925, STER or STERLING — 92.5% silver, the standard for sterling. Older American pieces sometimes carry 900 for coin silver. 800 and 835 are continental silver standards and turn up on inherited European pieces regularly.
The second mark: who made it
Alongside the quality mark there is often a second, stranger one — initials, a symbol, a shape, a name in a shield. That's the maker's or sponsor's mark. In the United States a piece carrying a quality stamp is supposed to carry the maker's registered trademark with it, which is why the two so often sit side by side.
British and much European jewelry goes further and carries a full hallmark in the strict sense: a set of marks struck by an assay office that independently tested the metal. A British hallmark can include a standard mark such as the lion passant for sterling, a town mark identifying the assay office, a date letter giving the year, and the maker's mark. It's the most informative marking system you're likely to encounter, and it's why a piece from a grandmother's side of the family sometimes carries four or five separate stamps.
A maker's mark is worth photographing before you do anything else with a piece. It's frequently the difference between "an old gold brooch" and a brooch by someone whose name means something.
Why your ring might have no mark at all
Unmarked doesn't mean not precious. Four ordinary explanations, in roughly the order we see them:
- It wore off. A stamp sits on the surface. Fifty years against a knuckle takes it away.
- It was sized. When a ring is made smaller, a section of the shank comes out — and the mark is usually stamped in exactly that section. A resized ring is often an unmarked ring afterwards.
- It predates the practice, or came from somewhere that didn't require it. Handmade, antique and some imported pieces were simply never marked.
- It isn't precious metal. Sometimes this is the answer. It's a possibility, not a conclusion.
What a stamp does and doesn't prove
Worth understanding clearly: a quality mark is a claim made by whoever made the piece. It isn't an independent certificate, and it isn't a guarantee. Marks can be worn to the point of misreading, older tolerances allowed pieces to run slightly under their stamp, and marks can be applied to pieces that don't merit them.
Which is why anyone in the trade who buys gold tests the metal rather than reading the stamp and stopping there. Testing is quick, and it's the only thing that actually settles the question. The stamp tells you where to start looking; it doesn't finish the job.
Before you sell, insure or clean anything
- Don't polish it first. Buffing softens the very marks you want read, and on a plated or gold-filled piece it can cut through the layer entirely. This is the most common irreversible mistake people make.
- Photograph the marks while they're legible, along with the piece itself.
- Keep the pieces together. Boxes, papers, receipts and old appraisals all carry information the metal doesn't.
- Don't sort by eye. The least impressive-looking thing in the box is regularly the one that matters.
Bring it in and we'll read it with you
Chapel Hills buys estate jewelry and gold, and we look at inherited pieces constantly. Bring what you have to the showroom and we'll go through the marks with you and tell you what we're seeing — whether or not there's a transaction at the end of it. If you're keeping a piece and want it documented for insurance, appraisals are done in house; see our appraisals page. If a mark has been worn away or lost to a sizing and you'd like the piece looked at properly, our bench is here in the store.
Two related reads if they're closer to your situation: our guide to buying and selling estate and vintage jewelry in Pittsburgh, and — if what you're looking at is a chain you're thinking of buying rather than one you've inherited — our guide to 14K yellow gold chains. You can also browse the estate collection to see the sort of pieces that come through.
Or just bring it by: 503 Freeport Road, Pittsburgh, PA 15215, or call 412-782-1757. Bring the box and the paperwork too — those are sometimes the interesting part.