Assay offices are institutions set up to assay (test the purity of) precious metals. This is often done to protect consumers from buying fake items. Upon successful completion of an assay (i.e. if the metallurgical content is found 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 on the item to certify its metallurgical content. Hallmarking first appeared in France, with the Goldsmiths' Statute of 1260 promulgated under Étienne Boileau, Provost of Paris, for King Louis IX. US assay offices 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. General overview and function of U.S. assay offices 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). US assay offices, current Current U.S. assay offices include the following: The Philadelphia Mint – 1792 to date The Denver Mint – 1862 to date. It served as an assay office until 1906, when coinage operations began. The San Francisco Mint – 1852 to date. Coinage operations were suspended in March 1955, but the plant continued to operate as an assay office. In 1962, its official designation was changed from mint to assay office. Coinage operations were again authorized in 1965. The West Point, New York Bullion Depository – 1938 to date. It is operated as an adjunct of the New York Assay Office. US assay offices, historical The Charlotte, North Carolina Mint – 1835 to 1861. After the Civil War, the plant was reopened in 1868 as an assay office until 1913, when it was ultimately closed. The New Orleans, Louisiana Mint – 1835 to 1942. Coinage operations were conducted here from 1838, but were suspended from 1861 until