Hallmarks indicate how pure the precious metal or alloy is. The hallmarking and testing of precious metals is regulated by Act No. 539/1992 Coll., the Act on Hallmarking and Testing of Precious Metals (Hallmarking Act).
The marks are stamped with a special stamp with pictograms. The marks for gold contain, for example, an eagle or a rooster, for silver a chamois and a hare, and for platinum a crown.
The mark also contains a letter that indicates the branch of the Assay Office that issued the hallmark.