Reading the Marks
How to find and read jewelry hallmarks
Jewelry hallmarks are tiny, cryptic, and sometimes worn nearly smooth. But they contain the information that determines what a piece is worth: whether the metal is precious, how pure it is, who made it, and where it came from. Learning where marks hide and how to interpret them turns an intimidating pile of inherited jewelry into something you can sort and evaluate. This guide covers the four main types of marks and where to look for them on each kind of piece.
Where to find hallmarks
Marks appear in specific, predictable locations depending on the type of piece. On rings, marks are stamped inside the band, often on the side opposite the setting. On necklaces and bracelets, the clasp is the usual location — check the clasp itself, the jump ring connecting the clasp to the chain, and sometimes the tongue of a box clasp. On earrings, marks appear on the post, on the back of a stud, or inside the hoop. On brooches and pins, look on the pin mechanism, the trombone catch, the back of the clasp plate, and sometimes a small tag soldered to the back. Hallmarks are usually very small and easily missed — use magnification, raking light, and a steady hand. When in doubt, photograph everything and zoom in.
Type one: metal fineness marks
Fineness marks indicate how pure the metal is. US gold uses karat stamps: 10K (41.7% gold), 14K (58.5%), 18K (75%), 22K (91.7%), 24K (pure). Much of Europe uses three-digit decimal marks: 375 for 9K, 585 for 14K, 750 for 18K, 917 for 22K, 999 for pure gold. Silver is typically marked 925 for sterling (92.5% pure) or "Sterling." Platinum uses PT950, 950, PT900, Plat, or "Irid Plat" for iridium-platinum alloys. These marks establish the floor value of the metal itself.
Type two: maker's marks
Maker's marks identify the designer, workshop, or manufacturer. They often appear as stylized initials, a distinctive symbol, or a small registered logo. Maker's marks are typically the second mark you see on a piece, often right next to the fineness mark. For signed designer jewelry, the maker's mark can be the single most important factor in value — an identical piece is worth multiples more when it carries a recognized maker's mark. Photograph every small symbol or set of initials, even when you cannot identify them. A specialist can usually attribute marks that look abstract or random.
Type three: assay and country marks
Assay marks indicate that a piece was officially tested and confirmed to contain the stated metal purity. British gold and silver carry hallmarks applied by official assay offices in London (leopard's head), Birmingham (anchor), Sheffield (rose or crown), and Edinburgh (castle). French gold pieces carry an eagle's head mark for 18K gold. Italian gold is often marked with a three-digit fineness number plus a diamond-shaped cartouche containing a provincial number that identifies the maker's location. These marks are especially helpful for identifying European pieces and confirming authenticity.
Type four: date letters
Some European hallmarking systems include a date letter — a single letter in a specific font and shape that indicates the year the piece was assayed. British date letters rotate through the alphabet in different fonts each cycle. This is how a British sterling piece can be dated to a specific year, similar to Rookwood pottery marks. Not all jewelry carries date letters, but when present they allow precise dating. American jewelry typically does not use formal date letters, though patent date marks and design registration numbers sometimes help date pieces.
Common fake and misleading marks
Not every mark indicates precious metal. "German silver" and "nickel silver" are base metal alloys — no silver content at all. Marks like GP, GE, EP, HGE, and RGP indicate gold plating. 1/20 12K GF means gold filled — a thin sheet of gold bonded to a base metal core, not solid gold. EPNS means electroplated nickel silver, a silverplated base metal. Some imported jewelry carries unofficial stamps designed to look like hallmarks without guaranteeing content. When marks look unusual, photograph them for a specialist.
Signed designer pieces
For 20th-century jewelry especially, a maker's mark transforms an ordinary-looking piece into a documented designer work. Signed pieces by important 20th-century designers — both fine jewelers and high-end costume jewelry makers — can sell for many times what identical unsigned pieces bring. Always photograph every tiny mark before making any decision about a piece, because the signature is often the most important feature in establishing value.