How to Read Jewelry Hallmarks and Maker’s Marks

Turn the ring over and there’s a stamp about the size of a grain of rice. 585? GF? A tiny crown? A number followed by “AR”? It looks like nonsense until you know that those marks are answering four different questions.

The four kinds of marks

Most confusion comes from treating every stamp as the same kind of thing. They aren’t.

• Purity marks say what the metal is (14K, 925).
• Plating and filled codes say what it isn’t (GP, GF, EPNS).
• Maker’s marks say who made it, whether that’s a name, initials, or a logo.
• Country and date clues say where and roughly when (“Occupied Japan,” a copyright symbol, a British assay mark).

A single piece can carry one of each, or just one, or nothing.

Where to look

Marks hide in predictable places. On a ring, check the inside of the band. On a chain, look at the clasp and the little tag next to it. On a brooch, check the back, near the pin stem. On a pendant, look at the back and the bail. For earrings, try the post, the back, and the closure. Bracelets are usually marked on the clasp, the hinge, or a small tag.

A jeweler’s loupe is cheap and worth having. No loupe? Use your phone camera and zoom in, in bright light. Marks wear down, so a partial stamp is normal. A blurry photo of the right spot is more useful than a sharp photo of the wrong one.

Purity marks: gold, silver, and platinum

Gold is marked in karats or in parts per thousand.

• 10K or 417
• 14K or 585
• 18K or 750
• 22K or 916
• 24K or 999 (pure, and soft)
• 9K or 375 is common on British and European pieces

Silver is usually 925, STERLING, or STER. You’ll also see 800 and 835 on European pieces (lower purity) and 900 on older American coin silver. Platinum is typically PLAT, PT, or 950.

For the tests that back these stamps up, see our guides to telling if gold is real and if jewelry is sterling silver.

Plating and filled codes

These are the marks that tell you a piece is not solid, and they matter as much as the purity marks. GF or gold filled is a real, thick layer of gold bonded over a base metal. A mark like 1/20 12K GF means the gold is one-twentieth of the piece’s weight and 12 karat. GP (gold plated), GEP, HGE (heavy gold electroplate), and RGP (rolled gold plate) are all plating, and plating can wear through. Vermeil is gold over sterling silver.

On silver, EPNS (electroplated nickel silver) and silver plate mean silver plated over a base metal. And nickel silver or German silver contains no silver at all, despite the name. Our gold filled vs plated vs solid guide goes into what each is worth.

One more you’ll see on stone-set pieces: CTW (or TW) means carat total weight, the combined weight of the stones (usually diamonds).

Maker’s marks

A maker’s mark can be a full name, initials, a logo, or a small symbol. In the US, a quality stamp is supposed to come with the maker’s registered trademark, which is why you’ll often see a name or logo right next to the 14K or sterling stamp. Signed costume jewelry (think Trifari, Coro, or Miriam Haskell) usually carries the name, sometimes with a copyright symbol or patent note.

Handmade pieces are different. Independent makers often stamp their initials or a small personal symbol, or nothing at all. Initials alone are hard to trace, since the same two letters can belong to plenty of different makers, so the seller is the best source, and a good listing will say who made it.

Researching a mark

Photograph the mark up close. Search the exact letters, or describe the symbol in words, plus “jewelry mark.” For US company names, the USPTO trademark search can show who registered a name and when. Then look at sold listings for the same mark. If the pieces that come up look like yours, you probably have the right maker.

Country and date clues

The words and symbols on a piece can date it, especially costume jewelry.

• “Occupied Japan” means made under the Allied occupation, roughly 1947 to 1952.
• “West Germany” means made between about 1949 and 1990. Plain “Germany” doesn’t narrow it down.
• “Czechoslovakia” means made while that country existed, from 1918 to 1992.
• A copyright symbol on costume jewelry generally means the mid-1950s or later.
• “Pat. Pend.” means a patent application had been filed. A patent number means one was granted, and you can look that number up in the USPTO patent database to date the design.

British hallmarks

A full British hallmark is a set of tiny pictures, each answering one question: the sponsor’s (maker’s) mark, a standard mark for the metal, an assay office mark, and often a date letter. A walking lion (the lion passant) means sterling silver in England. The assay office mark tells you where it was tested: a leopard’s head is London, an anchor is Birmingham, a castle is Edinburgh, and a rose is Sheffield (which used a crown before 1975).

Italian marks

Italian pieces often carry a number plus two letters, sometimes with a star. The number identifies the manufacturer and the letters are the province, so AR is Arezzo (a big center for gold and silver), VI is Vicenza, AL is Alessandria, FI is Florence, and MI is Milan. That tells you who made it and where, not how pure the metal is, so look for a separate purity stamp like 925 or 750 nearby.

A stamp isn’t proof

Stamps can be wrong, and they can mislead in a sneakier way: a clasp can be marked 14K while the chain it holds isn’t solid, and a listing that says “14K” may only be describing the clasp. Treat a mark as a strong clue, then confirm it with a test, especially for anything expensive.

What if there are no marks?

Not automatically a problem. American pieces from before the 1906 Stamping Act often have no quality mark, and so do very small pieces, heavily worn ones, and plenty of handmade work. If you’re buying, ask the seller how they know what it’s made of. If you’re selling, say “unmarked” plainly, say whether you’ve tested it, and don’t promise a metal you can’t back up.

Photograph the marks

If you’re selling, a close-up of every stamp is the cheapest way to earn a buyer’s trust, and it’s the first thing an experienced buyer looks for. Our jewelry photography guide shows how. If you’re buying, ask for the photo. A seller who has the stamp will be happy to send it.

Marks are the closest thing jewelry has to a receipt. Once you can read them, a lot of pieces stop being mysteries and start being stories. And if you find one that stumps you, send it our way.