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The Encyclopedia of Horology

Glossary · Collecting

Hallmarks

Assay office marks certifying precious-metal content, often datable to a year.

Explanation

Hallmarks are official stamps struck on precious-metal watch cases to certify the metal standard and, in the British system, the assay office, date letter and maker's or sponsor's mark. Reading the marks can date a case closely — but the case date is not always the movement date, since movements were recased and cases were married to other movements. Import marks, tax marks and foreign control marks add further clues.

In the object catalogue

Catalogued objects whose own source record mentions “Hallmarks”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.