Fineness and hallmarks of precious metals
Fineness and maker's mark
In Italy the fineness of a precious metal, that is how much of the alloy is pure metal, is expressed by law in parts per thousand and must be stamped on the piece together with the maker's identification mark (Legislative Decree 251/1999).
Gold 750 parts per thousand
What you read on the jewel
The fineness, in parts per thousand, stamped inside the shape set by law for each metal (Presidential Decree 150/2002, Annex V).
The identification mark: an elongated hexagon with a five-pointed star, the number assigned to the maker or importer by the Chamber of Commerce and the code of the province where it is based (Presidential Decree 150/2002, art. 1 and Annex III, as amended by Presidential Decree 195/2014). The number shown is an example.
Figures and shapes are stamped into the metal, not raised. The marks are tiny: in the smallest size the fineness mark is 0.6 mm high and the maker's mark 0.4 mm (Annexes V and III).
Legal finenesses of gold: 750, 585 and 375 parts per thousand. Any fineness higher than the highest one set for each metal is allowed (Legislative Decree 251/1999, art. 3).