Costume jewelry rarely comes with a birth certificate, but it almost always leaves clues. No single clue proves an age on its own. Put several together and you can usually narrow a piece down to a decade or two.
Our signed ORA swan brooch carries the © mark from clue 2, and it's in the shop now for $27. It's the only one we have.
See the swan →
1. The maker's mark
Look on the back, the clasp, and the edges for a signature. A maker's name can date a piece by itself, since many companies changed their marks over time. Our guide to Sarah Coventry marks shows how, and signed vs. unsigned brooches explains what a mark does to value.
2. The copyright symbol
In the U.S., jewelry designs became copyrightable in the mid-1950s. A small © next to a maker's name generally means the piece is from about 1955 or later. A signed piece from a major maker without the © can be earlier.
3. Clasps and findings
Fasteners changed a lot over the years. Simple C-clasps point earlier, while safety catches, rollover locks and spring rings came later. Earrings follow a similar path: screw backs, then clip-ons, with pierced posts becoming common again from the 1970s on. See how to date a brooch by its pin back for the details.
4. Stones and how they're set
Prong-set and hand-set stones generally point to better quality and often earlier work, while glued-in stones are common in mid-century and later pieces. Foiled backs, paste, and aurora borealis coatings, which arrived in the mid-1950s, are all useful clues.
5. Metals and plating
Look for wear on high points. Base metal showing through gold-tone plating tells you about age and use. "Sterling" marks on American costume jewelry are common in the WWII era, when base metals were rationed. Our sterling silver guide helps you check.
6. Plastics
Plastics are great era markers. Bakelite peaked in the 1930s and '40s, thermoset in the 1950s and '60s, and lightweight acrylics and lucite later.
7. Style
Finally, step back and look at the design. Geometric Art Deco, big gold-tone Retro bows of the 1940s, sparkly 1950s rhinestones, and chunky 1970s pieces each have a look of their own.
See it in person: dating clues in the shop
Each of these shows at least one of the clues above. Each one is a single piece, so when it's gone, it's gone.
Shop the eras
Browse our full jewelry collection, mid-century jewelry, rhinestone jewelry and signed designer pieces.
Signed pieces in the shop right now:
- Crown Trifari tassel pendant necklace, signed and in gold-tone.
- Monet geometric collar necklace, 1960s navy enamel in the Egyptian Revival style.
- Monet textured bead necklace, 1960s silver-tone.
- Coro leaf statement necklace, 1950s gold-tone.
- Renoir copper triangle link necklace, signed mid-century copper.
- Speidel heart expansion bracelet, gold-tone with mother-of-pearl inlay.
- B. David rhinestone ear climbers, 1950s silver-tone clip-ons.
Keep browsing:
Mid-century jewelry →Signed designer jewelry →Rhinestone jewelry →
Keep reading: Vintage vs. Antique vs. Retro · Georgian vs. Victorian · What Is Enamel Jewelry?
What's the oldest piece of costume jewelry you own, and which clue gave its age away?