How to Read a 1920s Bracelet: Hallmarks, Engravings and the Art of Paste
A piece of old jewellery is rather like a witness who has been asked to keep quiet. It knows where it has been, who wore it and who paid for it. It simply won't say so unless you know which questions to ask.
I spent a good deal of time asking those questions while writing Freddie Felstead and the Sapphire Bracelet, in which a bracelet turns up in a London theatre wall after sixty years with an engraving that ought not to exist. No spoilers here. But the research was too much fun to keep to myself, so here is a short guide to investigating a 1920s bracelet, should one ever turn up in your attic.
First, the look
The style we now call Art Deco takes its name from the great 1925 exhibition of decorative arts in Paris. Jewellery of the period favours straight lines, geometry and contrast: white stones against coloured ones, crisp edges, repeating patterns that look as if they were drawn with a ruler.
Platinum was the metal of choice for the best pieces. It is strong enough to hold stones in very fine, open settings, which is why so much Deco jewellery looks almost like lace. Look closely at the edges and you may see millegrain, a line of tiny beads running along the metal, too small to notice until you do.
Examples: https://www.1stdibs.com/jewelry/bracelets/period/1920s/?stone=sapphire
Then, the stones
Sapphires, rubies and emeralds were often calibré-cut: shaped individually so that they sit edge to edge in a line, with no metal showing between them. It is fiddly, expensive work, and a long, unbroken row of perfectly fitted blue stones is one of the surest signs of a jeweller who knew what they were doing.
Then, the marks
This is where a bracelet starts to talk. French jewellery carries tiny official stamps, usually on the clasp. A dog's head means platinum, a mark used since 1912. An eagle's head means 18-carat gold. The maker's own mark sits in a small lozenge shape, and with patience (and a good reference book) it can lead you back to a particular workshop.
British pieces are trickier. Gold and silver have been hallmarked here for centuries, but platinum wasn't hallmarked in Britain until 1975. So a British platinum bracelet from the 1920s may carry no official mark at all, which is exactly the kind of gap a mystery writer enjoys.
A jeweller's loupe, a small 10× magnifier, costs very little and turns a smudge on a clasp into a story.
Then, the engraving
Engravings are the most personal clue of all. Initials, a date, a few words meant for one person only. They wear down with time, especially on the inside of a bracelet where it rubs against the wrist, so a sharp, clean engraving on an old piece is worth a second look. Was it added later? By whom? And why?
In The Sapphire Bracelet, the engraving reads DEAREST M · THE HOUR IS OURS. Freddie can't stop asking who M was. Neither, I confess, could I.
And finally, paste
Not every stone is what it seems. Paste is glass cut and polished to imitate gems, and in skilled hands it can be very convincing indeed. The French still call it strass, after Georges Frédéric Strass, an 18th-century Paris jeweller who made his name with it.
Paste isn't a swindle in itself. Plenty of fine paste jewellery was made to be worn openly, and some of it is now collectable in its own right. It only becomes a mystery when someone claims otherwise.
Which, as Freddie would tell you, is usually the moment to start paying attention.
Freddie Felstead and the Sapphire Bracelet is out on 15th November 2026: mybook.to/FreddieFelstead2
For more curiosities like this, about once a month and never more often, join the Felstead Gazette: freddiefelstead.com/newsletter
