Hallmarks: tiny marks, valuable clues
Where to find the marks on a piece of jewellery, how to photograph them for a scan, and why even a convincing stamp cannot tell you what it is worth.
Marcel Buth · Co-founder, IsItGOLD?
· 4 min read
A tiny number inside a ring. A faint symbol on a clasp. A row of marks on the underside of a silver spoon. These details are easy to overlook, and they can tell an important part of your object's story.
Before your next IsItGOLD? scan, take a moment to look for them — and always add a clear close-up of any marks you find alongside photos of the whole object.
What "hallmark" means
People often call any small stamp on jewellery a hallmark. Strictly speaking, an official hallmark records independent testing of the precious metal under a particular hallmarking system. A plain purity stamp or a maker's mark is not necessarily an independently verified hallmark.
Depending on the country and period, marks can show the claimed fineness of the metal, the maker or sponsor, the assay office that tested it, and sometimes the year. Not every object carries every type of mark.
A genuine fineness mark of 585, for example, means 585 parts of gold per thousand — about 14-karat gold. 750 corresponds to 18 karat, and 925 usually means sterling silver. The letters and symbols around a number matter too, so do not read an isolated number as the whole answer.
Where to look
- Rings: inside the band.
- Necklaces and bracelets: on the clasp, its tongue, the end pieces or a small attached tag.
- Pendants and earrings: on the back, the hanging loop, the post or another discreet surface.
- Silverware: underneath, behind the handle or near the base.
Use good light and, if you have one, a jeweller's loupe. Look for the whole group of marks, not just the largest number. Do not open a watch case or take a delicate piece apart just to find a stamp; a jeweller can do that safely.
Clean gently before the close-up
Dirt, skin oils, soap and cosmetics collect in tiny recesses. A surface can look clean while the grooves of a stamp are still filled, and that can make a mark hard to read even in a sharp photo.
Start with a soft, lint-free cloth. If the materials and condition allow it, clean the marked area gently with lukewarm water, a little mild soap and a very soft brush, then rinse and dry carefully. If you are not sure what the piece is made of — especially with gemstones, pearls, glued parts, thin plating or antiques — ask a jeweller before you use water.
Do not scrape the grooves with a needle, use abrasive polish or try to deepen the mark. Cleaning can reveal detail that survives; it cannot restore metal that has worn away. Years of wear, repairs or polishing can flatten a stamp until no photo will make it readable.
Photograph the mark with the object
The guided scan takes several photos of the same item. Use them for:
- The complete object.
- A view that shows where the mark sits on it.
- A sharp close-up of the entire group of stamps.
Use even light, avoid glare and tap to focus on the stamp. If reflections hide the grooves, try a second angle. Getting physically closer gives you more detail than enlarging a blurry picture with digital zoom. Check the photo before you upload it.
A readable mark gives the analysis useful context, but it will not read every mark, and a badly worn stamp may defeat it entirely. If you cannot read a mark yourself, say so in the description rather than guessing at its characters.
A stamp is a clue, not a value
Purity stamps and hallmarks can be forged, altered or copied. A convincing mark does not prove on its own that the whole object has the claimed composition. A missing or worn mark does not automatically mean a piece is fake, either.
No mark on its own tells you what an item is worth. The actual metal and its weight matter, and so do condition, workmanship, stones, provenance and the market for the piece. A stamped number shows none of that.
Read the marks together with the object, its history and everything else you know. A scan gives you an estimate, not a certificate of purity or a final valuation. When authenticity or a significant sale or purchase depends on the answer, have the item independently tested.
Before your next scan
Find the marks. Clean them safely. Photograph the whole item and the complete group of stamps, upload them together, and read the result as the estimate it is.
For more on official hallmarks, see the Birmingham Assay Office's guide to hallmarking. For caring for different materials, see GIA's tips on caring for jewellery. For current app features, see what's new.
