Utility items are nearly never made of pure silver or pure gold, because these metals are definitely too soft. That's why goldsmiths use alloys of precious metals with other additives.
How does it work in practice? I'll try to explain it using an example of the most popular sterling silver 925. This number (925) is the percentage amount of pure noble metal in the alloy, expressed in parts thousandths. It means that 925 silver contains 92.5% of pure precious metal and 7.5% of additives of other metals which are improving the functional properties of the alloy (increasing the hardness of the product for instance). This rule works similarly for the other noble metals. 585 gold contains 58,5% of pure gold for example.
Polish hallmarking law requires platinum, gold and silver jewelry to be examined and hallmarked in the Assay Office when:
- weight of single item made of silver alloy exceeds 5 grams,
- weight of single item made of gold or platinum alloy exceeds 1 gram.
Lighter products don't have to be hallmarked, so these items usually are not stamped with hallmarks at the office.
It means that officials in Assay Offices check the percentage amount of pure precious metal in the alloy, which is a product made from and they confirm it with the suitable mark. On the other hand, articles containing less than 5 grams of silver or less than 1 gram of gold or platinum are not hallmarked usually, but the goldsmith is a person who is fully responsible for the declared composition of the product.
The table below shows all actual hallmarks used in Assay offices in Poland:
Very important is that every jewelry piece has to be marked with it's creator's personal mark registered and approved by the Assay Office. The personal mark is the guarantee for the customer of purchasing a jewelry in accordance with the declared fineness.