A hallmark is one of Britain's oldest consumer protections. Once you know how to read one, every piece of antique or secondhand jewellery tells you exactly what it is, where it was tested, and when it was made.
Marmalade Fine Jewellery · Chiswick, London · Gemmologists and Registered Valuers
What a hallmark is
A hallmark is an official set of marks stamped into a piece of precious metal by an independent Assay Office, certifying that the metal has been tested and meets the legal standard of purity. It is not a maker's signature or a decorative feature. It is a guarantee, enforced by law, that the metal is what it claims to be.
The word itself comes from Goldsmiths' Hall in London, where the Goldsmiths' Company has tested precious metals since the fourteenth century. The practice of compulsory assaying dates to a statute of 1300, making British hallmarking one of the oldest forms of consumer protection in the world. When you hold a piece of hallmarked British silver or gold, you are holding something that carries more than seven centuries of trust.
The marks explained
A full British hallmark typically consists of four marks, each telling you something different about the piece.
Sponsor's mark
The maker's or importer's initials in a distinctive shield. This identifies who submitted the piece for assay.
Fineness mark
The purity standard, shown as a number (925 for sterling silver, 750 for 18ct gold) or traditional symbol. For British silver, the lion passant, a walking lion, has indicated sterling since 1544.
Assay office mark
The town mark of the testing office. London uses a leopard's head; Birmingham an anchor; Sheffield a crown (rose from 1975); Edinburgh a castle.
Date letter
A letter indicating the year of assay. Each office ran its own independent cycle, so the same letter in different offices represents different years.
Duty mark
A portrait of the reigning monarch, struck 1784 to 1890 to show excise duty had been paid. Its presence immediately dates a piece to that period.
How to read a hallmark
Look first for the fineness mark. The lion passant tells you the metal is sterling silver; a number (750, 585, 375) tells you the gold carat; an orb indicates platinum. Next, find the assay office mark: the anchor is Birmingham; the castle, Edinburgh; the crown or rose, Sheffield; the leopard's head, London.
Then find the date letter and use the lookup below. Because each office ran its own alphabet cycle, and because the cycles repeat roughly every 25 years, a single letter returns several candidate years. The exact year depends on the style of the letterform and the shape of the shield around it, details our valuers can read at a glance from the piece in person.
If a monarch's head is present, the piece dates from 1784 to 1890.
