Hallmarking in the uk
What does your mark mean?
PURITY MARK METAL TYPE What do the numbers mean?
925 Sterling Silver
999 Fine Silver (as in most metal clays)
375 9ct Gold
585 14ct Gold
750 18ct Gold
A complete hallmark consists of three punch marks:
Sponsor's mark (your mark or the manufacturers mark)
Metal and fineness (purity) mark
Assay office mark (London, Birmingham, Sheffield or Edinburgh)
Sometimes there are other marks applied such as a date mark but these are not a legal requirement.
In the UK, any person that sells precious metals must display on their
premises (including pop ups) in a conspicuous position, or on their
website a Hallmarking Act 1973 notice as approved by the British
Hallmarking Council.
Currently, all Silver items over the weight of 7.78g, and any gold items over the weight of 1g must be hallmarked by law.