Assay office

Assay offices are institutions set up to assay (test the purity of) precious metals, in order to protect consumers. Upon successful completion of an assay, (i.e. if the metallurgical content is found to be equal or better than that claimed by the maker and it otherwise conforms to the prevailing law) the assay offices typically stamp a hallmark, punze, or poinçon on the item to certify its metallurgical content. Hallmarking first appeared in France, with the Goldsmiths' Statute of 1260 promulgated under Etienne Boileau, Provost of Paris, for King Louis IX.

Title 15, Chapter 8, Section 291 of the United States Code makes it unlawful to stamp goods in the United States with "United States assay" or any similar stamp which gives the impression that the item has been officially assayed by the United States government.

Assay offices did and do exist in the U.S., but they are affiliated with the government's coinage mints and serve only the government's purposes in that field. They are not involved in hallmarking, as there has never been a hallmarking scheme in the U.S.

In the 1800s, the functions of assay offices in the U.S. included receiving bullion deposits from the public and from mining prospectors in the various American territories. The assay offices that still operate today function solely within national coining system (including bullion coinage for sales to investors).

Current U.S. assay offices include the following:

In the United Kingdom (UK), the Hallmarking Act 1973 makes it an offence to describe as platinum, gold or silver an item which is not hallmarked as appropriate or exempt from hallmarking. In July 2009, following a proposal by the British Hallmarking Council, an amendment to the Act also brought palladium under the hallmarking regime.

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