A guide to resources for identifying hallmarks and understanding the process of assaying
A hallmark is a stamp applied to an article of precious metal (gold, silver, platinum and palladium) after testing by an official independent assay office, which denotes the fineness of quality.
Hallmarking dates back to the craft guilds in the 1300s and is the oldest form of consumer protection which in view of the historically high price of precious metal and with globalisation, is more important than ever.
Precious metals are too soft to be used unless alloyed with other metals. Therefore all precious metal articles must be “assayed” or tested for purity before being offered for sale in the United Kingdom or Ireland.
Assay offices test the purity of precious metals, in order to protect consumers. Articles less than a prescribed weight may be exempt.
Assay office mark
Also known as the 'town mark', this identifies the office at which the assaying and marking were done.
Maker’s or sponsor’s mark
This mark consists of the initials of the maker surrounded by a shield. An assay office will only accept a design for this mark if it is totally distinct from any other mark registered with that office.
Metal and fineness [purity] mark - Standard mark
This is a traditional mark indicating the purity of the metal. It will either be represented by a numerical value, or a symbol.
Sterling silver 925 parts per thousand
Britannia silver 958 parts per thousand
22 carat gold 916 parts per thousand
18 carat gold 750 parts per thousand
14 carat gold 585 parts per thousand
9 carat gold 375 parts per thousand
Traditional fineness symbols
The date letter shows the year that assaying was carried out. Prior to 1975 the date letter varied for every office, after that it was uniform throughout the United Kingdom.
Since 1999, the date letter has been voluntary. Most silver and goldsmiths making bespoke pieces will still opt to use the date letter, however for mass produced silver items it saves the importers money to leave it off.