Many countries have laws that govern how precious metals are sold and often, to protect the consumer, insist that a hallmark is applied. Assay is the name of the test that is carried out, before the relevant hallmark is applied.
In the UK, it is a legal requirement for all gold jewellery over 1 gram and all silver jewellery over 7.78 grams to be officially hallmarked by the British Assay Office.There are four main assay offices in the UK; all of whom have their own hallmark. All items assayed in Birmingham have an anchor stamped into them; Sheffield, a Rose; Edinburgh, a castle; and London, a leopard.
The hallmark includes the purity of the metal: 375 being 9k gold; 585 being 14k gold; 750 being 18k gold; and 925 being Sterling Silver. It is also a legal requirement for the hallmark to carry the sponsor’s mark; this is normally the initials of the jewellery importer, retailer or the manufacturer.
In the UK there is also an option for the hallmark to carry a year symbol, which is intended to help further generations trace jewellery back to the date their possession was hallmarked.
In the UK the history of assay testing and hallmarking precious metals dates back to 1300. Under the instruction of Edward I, hallmarking became a legal requirement for Pewter, Silver and Gold in order to protect the public against fraud, and to protect legitimate traders against unfair competition.
