An article of precious metal has been marked according to requirements if the manufacturer’s or importer’s sponsor’s mark and fineness mark or a combined sponsor’s and fineness mark have been affixed to it. The requirements are established in the Precious Metal Articles Act.

• The sponsor’s mark indicates which manufacturer or importer is responsible for ensuring the conformity of the article of precious metal with the requirements. The sponsor’s mark is a compulsory mark in Estonia. The manufacturer (a jeweller or a manufacturing company) and the importer must affix its sponsor’s mark to each manufactured or imported article of precious metal.

The sponsor’s mark may be a letter, a combination of letters or a symbol which is clearly distinguishable from other sponsor’s marks and has been entered in the State Register of Sponsor’s Marks.

• The fineness mark shows which standard the alloy of the article of precious metal corresponds to.
• The control mark is the Estonian assay mark. The control mark certifies that the fineness of the precious metal used for the manufacture of the article has been verified in a laboratory and conforms to the standard.

The Estonian control mark, the “lion”, is affixed to articles of precious metal only by Metrosert’s test laboratory, the Estonian Assay Office, which is the state’s authorised assayer.

• The date letter shows the year of manufacture of the article. Since 1993, Estonia has been using capital letters of the Estonian alphabet in non-italic type as date letters. Pursuant to the valid legal act, date letters have been established until the year 2016; due to their infrequent use, however, no date letters have been established for subsequent years.