Stamping and Hallmarking your Metal Clay work

Rules about hallmarking or stamping your work differ from country to country. Always check with the authorities in your country to find out how you should mark your work for sale. On this page you'll find some resources to help you.

Hallmarking in the UK

The testing and marking of jewellery and silverware to guarantee the precious metal content of an article has been carried out by the Goldsmiths' Company since 1300. The process is known today as hallmarking, which originally meant 'marked at Goldsmiths' Hall'. The techniques of sampling, testing (assaying) of the precious metal content (fineness) and marking have altered over the centuries, but the principle of providing a guarantee for manufacturers, importers, retailers, and the eventual purchaser, remains the same. It is one of the oldest forms of consumer protection.

The British Hallmarking Council

Nowadays hallmarking is carried out in the UK not only by the London Assay Office, at Goldsmiths Hall, but also by the Birmingham, Edinburgh and Sheffield Assay Offices. Visit these links to find out more about hallmarking in the UK.

London Assay Office

Birmingham Assay Office

Sheffield Assay Office

Edinburgh Assay Office


Help with Hallmarks App

Crack the Code......easily work out the age of a piece of jewellery or silverware.

The Help with Hallmarks App is available for iPhone/iPad as well as Android devices, and enables users to quickly research and identify the date letter on precious metal jewellery and silverware. The App is easy to use and includes date letters from the eleven key Assay Offices in the UK and Ireland, going back as far as 1544 when the date letter was first introduced as part of the hallmark. Priced at only £9.99, the App also contains useful information relating to hallmarks, and will be an invaluable “on the go” tool for those with an interest in jewellery and silverware, retailers, pawnbrokers, jewellery valuers, assessors and insurers as well as the wider jewellery industry and the general public.



Guide for the Jewelry, Precious Metal and Pewter Industries

Federal Trade Commission guide.

Rules for the USA - Jewelers Vigilance Committee

The Jewelers Vigilance Committee was formed in 1912 to provide education and self-regulation to the jewelry industry. Members operate under the highest standards of business practice after pledging to comply with all laws applicable to the jewelry industry and make accurate representations about the products they sell.