In 1975, Finland signed an international convention on the checking and marking of article made of precious metals. With this convention in place, a common market for articles made of precious metals, within the area formed by the member states, was created. Articles marked with the CCM mark (Common Control Mark) can be released onto the market as such in all signatory states.
An article can be marked with a CCM mark by an authorised assay office – in Finland, Labtium Oy – after the article has been checked and found to be in conformity with the requirements of the treaty. Each signatory state has an authorised assay office that is authorised to mark articles.
A complete series of CCM marks includes a CMM mark indicating the fineness of the precious metals, a national hallmark, a responsibility mark, and a fineness mark.
On the international website of the Hallmarking Convention, the official texts of the convention, including other texts, can be found.