925 Sterling Silver: Hallmark Guide
What does 925S mean?
925 indicates 925 parts of silver by weight in 1,000 parts of alloy, or 92.5%. In Norway the number can appear as 925S; the term sterling is also used for this fineness. Norwegian precious-metals legislation defines fineness by the number of weight units of pure metal in one thousand weight units of alloy.
925, 925S and sterling
The number is the fineness designation. The letter S and the word “sterling” also appear in marks, but hallmark systems and combinations differ by country and period. For example, a British hallmark may combine a sponsor’s mark, a fineness mark and an assay-office mark. British rules should not automatically be applied to Norwegian or other foreign objects.
Read the complete mark sequence
A 925 mark alone does not identify who made an object, where it was assayed or when it was produced. Look for a maker’s or responsibility mark, any control marks, town marks and date letters. Compare the marks with the system used in the relevant country and check whether they are consistent with one another.
How it differs from silver plate
Sterling silver is a silver alloy. Silver plate has a base material covered by a thin layer of silver, so it should not be assessed as though the whole object were 925 silver. A number or word alone does not guarantee authenticity; wear, misread or false marks and objects made from mixed components are possible.
Weight and value
Fineness and the net weight of the silver parts provide a starting point for estimating metal value. Knife blades, filling, stones and other materials must be excluded from the silver weight. Maker, designer, pattern, workmanship, age, rarity, provenance and condition may give an object collector value beyond its metal content.
Sources and further reading
- Norway’s Precious Metals Act, section 4 – the Norwegian basis for fineness expressed per thousand by weight.
- Store norske leksikon: gold and silver marks – background on Norwegian precious-metal marks.
- Sheffield Assay Office: UK hallmarks – an example of why marks must be interpreted within a country’s system.
- See also OBA’s entries on 830S silver and silver.
For an overview of metal purity, gold carats and calculations, see fineness and fineness marks.
