Hallmarking is an ancient method of safeguarding consumers, and those trading in jewellery and precious metal and the word itself, stemming from 'marking goods at the (Goldsmiths) Hall' has its origins back in the 1300s.
Hallmarking involves testing articles made of precious metal - such as Platinum, Gold, Silver and most recently Palladium - and marking them to indicate that they are of a minimum standard of purity. Precious metals are rarely used in jewellery in their pure form and even an expert cannot tell how much valuable metal an article may contain, without testing it. The Hallmarking Act 1973, therefore requires that all precious metal articles offered for sale in the UK have a hallmark applied by an independent assay office to guarantee the precious metal content of the item.
The article will be tested (assayed) and then marked to an internationally recognised standard of fineness, shown in parts per thousand, such as 925 (Sterling Silver) or 375 (9ct Gold). The only exceptions are items which are light and fall under the exemption weight.
There are currently four UK Assay Offices who are permitted to apply the UK hallmark and they all work independently of one another. They are based in London, Edinburgh, Birmingham and Sheffield and are all very different organizations. The British Hallmarking Council is a body created by the Hallmarking Act 1973 to supervise the activities of the four assay offices with regard to hallmarking and ensure there is adequate provision of hallmarking within the UK.