Sponsor's mark, 375 in an oval, and an assay office town mark. An independent guarantee, not a claim.
The British and Australian minimum legal gold standard4 references
British hallmarking has run continuously since the fourteenth century and is still compulsory: with limited weight exemptions, an article may not be sold as precious metal in the UK unless it has been independently assayed and struck by one of the four remaining assay offices. That makes a British hallmark categorically different from an American stamp — it is a third party's test result, not the maker's assertion.
A modern compulsory mark has three parts. The sponsor's mark identifies who submitted the article, in a shaped shield unique to them. The fineness mark gives the standard as a number — 375 for 9 carat, in an oval for gold. And the assay office mark identifies which office tested it: a leopard's head for London, an anchor for Birmingham, a rose for Sheffield, a castle for Edinburgh.
A date letter was compulsory until 1999 and is optional now, but where present it fixes the year of assay exactly, which is why British jewellery can often be dated to the year while American work of the same period cannot. Traditional pictorial fineness marks — a crown for gold, a lion passant for sterling — are also optional additions.
The exemptions matter for small items. Below roughly 1 gram for gold, 7.78 grams for silver, 0.5 grams for platinum and 1 gram for palladium, hallmarking is not required, which is why a very light chain or a pair of small earrings may carry only a fineness mark or nothing at all.
London leopard's head · Birmingham anchor · Sheffield rose · Edinburgh castle
Establish which of these you are holding before judging it. A genuine piece read against another reference's rules will look wrong when it is not.
These apply to this model and not to the rest of 375. Work them alongside the maker's general checks, not instead of them.
A genuine compulsory mark has a sponsor's mark, a fineness number and an assay office mark, struck at the same time and usually in a line. Mismatched shield shapes, two different office marks, or a date letter that does not belong to the office shown are all signs of a made-up set.
Assay office date letter tables are published and freely available. The letter's shape, case and surrounding shield all encode the year, and a letter that does not exist in that office's cycle is conclusive.
Gold under about 1 gram, silver under 7.78 grams and platinum under 0.5 grams need no hallmark in the UK. An unmarked light chain is not necessarily suspect, and this exemption is widely misunderstood.
The marks do not add metal value, but they add confidence and they date the piece.
An orientation for honest, unrestored condition — never an appraisal, and never a quotation.
Lovenhall RingThe mark tells you what the metal claims to be. The instrument reads the setting and the stones together and gives a range to orient you — before anyone charges you for an appraisal.