It has a higher silver proportion than 925 sterling silver.
Read the number with the sponsor and assay-office elements of the complete hallmark.
Common interpretation
95.8% silver; Britannia silver standard in the UK
Material category
Silver alloy
What the mark can suggest
958 is a recognized UK silver fineness of 958 parts silver per 1,000, commonly called Britannia silver.
What it does not prove
- That a lone number is a complete UK hallmark
- Age or maker attribution
- Condition, originality, or value
What to check next
- 1Photograph every hallmark element
- 2Compare symbols with the relevant assay-office reference
- 3Avoid aggressive polishing until condition and surface details are recorded
Frequently asked questions
Is 958 silver?
958 is the recognized UK Britannia silver fineness, claiming 95.8% silver.
Is 958 purer than 925?
Yes as a fineness claim: 958 indicates a higher silver proportion than 925.
Sources and further reading
This guide summarizes the official and institutional references below. Open the original source for its full scope, jurisdiction, definitions, and updates.
UK Government / British Hallmarking Council
Hallmarking: fineness guidanceOfficial reference for recognized UK precious-metal fineness standards.
https://www.gov.uk/government/publications/hallmarking-fineness-guidance
UK Government
Hallmarking is the law: guidance summaryExplains compulsory elements of a UK hallmark and how fineness is expressed in parts per thousand.
https://www.gov.uk/government/publications/hallmarking-guidance-notes/hallmarking-is-the-law-guidance-summary
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