Flip over almost any good piece of costume jewellery and there is a chance you will find a small stamped word or symbol on the back. That is a maker's mark, and it is the most useful dating clue you have — as well as the easiest thing for a copyist to fake.
Costume jewellery was made to look expensive, not to last for ever. Diamanté was set into base metal, plating was thin, and thousands of pieces were thrown away when fashions moved on. The survivors carry a surprising amount of information in a very small space, if you know where to look.
Where to look for a mark
Marks sit on the back or the underside, and often in places you would not think to check. Good light and a jeweller's loupe — 10x is plenty — make the job much easier.
- Back of a brooch, on the flat plate rather than the pin stem.
- On a bracelet, usually the clasp or the fold-over tongue.
- Earrings: the clip mechanism, the screw-back plate or the reverse of the earring.
- Necklaces: the clasp, the hook, an end cap or a jump ring near the clasp.
- Pendants, lockets and charms: on the back or the bale.
If the mark is not where you expect it, keep going. Companies moved their stamps around over the decades, and some pieces were signed on a tag that has long since been lost.
Reading what you have found
A genuine maker's mark is part of the metal. It was struck, stamped or cast in at the time of manufacture, so it sits in the surface: the edges may be soft from wear, and plating sometimes wears away inside the letters. Marks scratched in afterwards with a needle, or printed on a paper label, are a warning.
Names and symbols to know
American costume jewellery dominates the market. Trifari used a crown above the letter T from the late 1930s, and its later pieces often carry a copyright symbol. Coro signed in script, and its British arm, Corocraft, marked pieces sold here. Monet's earlier work appeared as Monocraft; Napier, Weiss, Lisner, Kramer, Sarah Coventry and Avon all signed in their own house styles.
In the UK, look for Exquisite and Sphinx, two well-known mid-century British marks, and for pieces stamped "Made in England" or "Foreign". "Czechoslovakia" is another useful one: the country split in 1993, so a piece marked that way was made before then.
Marks that are not maker's marks
"Made in Austria", "Sterling", "Gold Filled" and "Reg. Des." tell you about origin, material or design registration, not the maker. A retailer's name stamped on the back means the piece was made for that shop, not necessarily by it.
The copyright clue
On American costume jewellery, a © generally points to the mid-1950s or later, when the way designs were protected changed. It is not a precise date, but it does rule out the 1930s and most of the 1940s.
Clasps and findings carry their own dates
Hardware is often a better guide than the mark, because it is harder to alter and easy to compare. Nothing here is absolute — clasps were replaced when they broke — but the pattern is reliable enough to use.
- J-hook and fish-hook clasps: mostly 1930s and 1940s.
- Barrel or corkscrew clasps: roughly 1930s to 1950s.
- Spring rings: common from the mid-century onwards.
- Fold-over box clasps: seen across the 1950s and 1960s, especially on bracelets.
- Lobster claws: a later fitting, standard from the 1970s.
- Magnetic clasps: modern.
Brooches tell the same story. An early piece usually has a C-clasp and a simple pin stem; a roller catch with a sliding lock is later, widely used from the 1950s. Earrings are just as revealing: screw-backs and clip-ons were the norm until pierced ears came back into fashion in the late 1960s and 1970s, so pierced-post earrings described as 1930s should make you pause.
Stones, settings and the feel of old metal
Vintage rhinestones were usually glass, foiled at the back to make them sparkle, and held in metal prongs. Because the foil is sealed inside a closed-backed setting, it survives well; when it does deteriorate, the stone turns cloudy with a biscuit-coloured patch behind the glass. That dulling is hard to fake convincingly and is one of the better signs of age.
Glued stones are a different matter. They appear on some period pieces, but a flat plate covered in glue-set stones with adhesive visible around the edges is more often a sign of cheaper, later production. Modern copies tend to use acrylic rather than glass, and the stones look uniformly bright with no depth. Tapping a stone gently against a front tooth is an old collector's trick: glass gives a faint ring, plastic a dull click.
Finishes can be dated too. The aurora borealis coating turned up in the mid-1950s, so an AB piece cannot be earlier than that. Weight matters as well: earlier costume jewellery was cast in pot metal or brass and feels substantial. A piece that looks heavy and ornate but weighs almost nothing is probably a modern casting.
Telltale signs of a modern copy
- Mixed signals: a 1930s style with a lobster claw clasp, or a Victorian-looking brooch with a roller catch.
- A famous name on a cheap base, with soft casting, bright plating and a wobbly version of a well-known mark.
- A blurred or doubled-up stamp where a maker's mark should be crisp.
- Stones on a flat plate with visible glue, all the same dull plastic.
- A printed sticker instead of a stamp, or fresh-looking felt on the back.
- No mark at all on a piece whose style is strongly associated with a signed maker.
A five-minute check before you buy
Turn the piece over first and look in the usual places. Read the mark with a loupe and decide whether it sits in the metal or on top of it. Work through the hardware — clasp, pin catch, earring fitting — then the stones, prong-set or glued, glass or plastic. Feel the weight. Finally, line the style up against the details. If the design says 1940s and the findings say 1980s, believe the findings.
If a seller cannot show you the mark, or the photographs avoid the back, treat that as your answer. Buy the piece you can see, not the story you are told, and you will rarely overpay.
Photo: cottonbro studio / Pexels
