Jewellery Hallmarks are a series of numbers stamped on jewellery or jewelry to denote that it conforms to a legal standard. These standards define the maximum proportion of base metals such as copper or nickel that is alloyed with gold jewellery or sterling silver jewellery. The presence of a hallmark on jewellery indicates that it has being assayed for its contents. British Hallmarks date back to the reign of Edward I. In 1300 a law passes stating that no gold or silver should be sold until tested. This brought to the tradition of gold hallmarks and Sterling Silver Hallmarks in the jewellery industry. The word hallmark means a 'mark' applied at Goldsmiths 'hall'.