A hallmark is a quality control mark placed on an article made of precious metal. Sometimes called a hall, assay or standard mark. It is usually applied after accurate independent testing by an assay office. In the United Kingdom, there are four Assay Offices which are legally empowered to test precious metal objects, and to apply a hallmark to them. These offices are in London, Sheffield, Birmingham, and Edinburgh.
Hallmarking is the world's first known instance of consumer protection law, in the UK it dates back to about 1300 AD. It is controlled by the Hallmark Act 1973, as modified by The Hallmarking (Hallmarking Act Amendment) Regulations 1998, and The Hallmarking (Hallmarking Act Amendment) Order 1998. The new regulations and standards became effective as from January 1st 1999.
A UK hallmark now contains at least three symbols, the sponsor's mark (often called a maker's mark), a number indicating the purity or fineness in parts per thousand, and an Assay Office mark.
There are additional optional marks, a date letter, a fineness symbol, and a common control mark.
Subject to certain exemptions, it is an offence to describe an hallmarkable article as being of gold silver or platinum unless it is hallmarked.
