Precious metals & hallmarks

Sometimes jewellery is clearly stamped with a hallmark which identifies the sponsor (the company which sent the item for hallmarking), when and where the piece was assayed (the metal purity checked) and which metals have been used - in the UK most commonly nine-carat gold, 18-carat gold and 925 sterling silver.

Sometimes pieces are not hallmarked - they may have been produced outside the UK, the stamps may have rubbed away over time, the piece may have been resized or converted, losing the mark in the process, or it may never have had one - small pieces below a certain weight are exempt from hallmarks.

Any piece sold here which does not have a hallmark has been fully tested to identify the metal.

Hallmarks can be fun to decipher! Have a look at your own jewellery:

First you'll usually find the sponsor's mark, often two or three letters or a little logo.

Then the fineness mark - 800, 925, 958 and 999 are silver.

375 is nine-carat gold, 585 14-carat gold, 750 18-carat gold.

850, 900, 950 and 999 are platinum (950 and 999 can also be palladium but that's less common to find). 

Next the assay office mark. The UK currently has four assay offices, in Birmingham (which uses an anchor symbol), London (a leopard's head), Sheffield (a rose) and Edinburgh (a castle). There used to be an assay office in Chester but this closed in 1964 and Chester hallmarks are considered quite desirable.

Usually the last stamp will be a date letter. Each assay office uses a different letter of the alphabet every year - you can google letter charts for each office to date your jewellery. Fun fact: on older jewellery the date letters don't necessarily denote a calendar year, for example Birmingham's year used to run from 1 July to 30 June, but all four UK offices standardised to 1 January-31 December in 1973.