Behind the Hallmarks: How We Authenticate Every Piece We Sell

It is easy to write a confident product description. It is much harder to earn it. Before any piece is offered for sale by us, it goes through a process designed to test every claim we might make about it — and if it fails, it doesn't go on the shelf. Here, honestly, is what that process looks like.

1. Reading the hallmarks

British hallmarking is 700 years of built-in evidence. We read the standard mark, assay-office town mark and date letter to establish metal, origin and — often — the exact year. Our detailed references make this precise: see our guides to reading silver hallmarks, silver hallmarks in full and gold hallmarks, plus the individual assay office guides. Worn or absent marks don't stop us — that's what the next step is for.

2. Testing the metal

Where marks are worn, foreign or absent, we confirm the metal with XRF analysis — X-ray fluorescence that reads the exact alloy and fineness without touching or damaging the piece. No acid, no filing. It's how we can price honestly on true metal content, and catch anything gilded or plated posing as solid.

XRF also catches subtler things a buyer would never see: a genuine Georgian piece with a later 9ct repair; a "platinum" mount that is actually white gold with rhodium plating; a gold case with a base-metal core. The reading takes seconds and tells the truth every time — which is why we test every piece, marked or not.

3. Assessing stones and pearls

Diamonds are examined for cut style and era (old mine, old European, transitional — see our old-cut guide), colour, clarity and any treatment. Coloured stones are checked for natural origin and treatment. And pearls get the decisive test: an X-ray to establish natural versus cultured — the difference, as our pearl guide shows, between hundreds and tens of thousands of pounds.

4. Verifying the signature

For signed pieces, the maison mark, serial number, hallmarks and construction are checked against archive references for Cartier, Van Cleef & Arpels, Tiffany and the other houses. A signature is only ever described as genuine when it has been verified — never assumed from a name. Our signed jewellery guide explains why this matters so much to value.

What we actually compare: the signature's font and depth for the claimed period (houses changed their marks over the decades, and fakers rarely match the right era), the serial number format, where the marks sit on the piece, and — most tellingly — whether the construction quality matches the house. A Cartier back is finished like a Cartier front. The cruellest fake we see is a genuine period jewel with a later-added signature: the piece is real, the name is not, and only archive comparison catches it.

5. Provenance and condition

Finally we research the piece's history where records allow, and grade its condition honestly — original versus altered, any restoration, wear to note. That honest grading is the point: it means the description you read is the piece you receive.

Red flags we see every week

• Lead solder repairs — grey, soft metal at joints. Amateur work that devalues a piece and often hides worse.
• "Married" pieces — a genuine top on a later mount, or two part-pieces joined. Check that hallmarks, wear and finish agree across the whole jewel.
• Modern brilliants in "period" settings — an Art Deco plaque should carry old-cut stones; crisp modern cuts in every position mean re-setting or reproduction.
• Cast reproductions — rounded detail, granular surfaces, seam lines where hand-made pieces show file and saw work. Turn it over: the back tells the truth.
• Too-perfect condition — a "Victorian" ring with zero wear to the shank or claws has usually been heavily rebuilt, or was made last year.

What you can check at home — and what needs testing

At home, with a £10 loupe: read the hallmarks against a reference chart (our hallmark guide is free); look for matching wear across the piece; check stones sit tight and match their neighbours in cut and colour; examine the back and fittings for solder lines and replaced pins.

What genuinely needs equipment or archives: exact metal fineness (XRF), natural-versus-cultured pearls (X-ray), stone treatments (lab), and signature verification (archive references). This is the honest boundary — anyone who claims to confirm a natural pearl by eye is guessing.

Why it matters to you

Every listing we publish — every date, every signature, every "natural pearl" — is earned through this process, not asserted. It's backed by clear condition reporting, 14-day returns and worldwide insured delivery. When you buy from us, you're buying the authentication as much as the jewel. Browse the collection knowing that, or contact us with anything you'd like verified.