830 Silver: What the 830 Stamp Means on Silver

830 is a silver fineness claim of 830 parts silver per 1,000, or 83.0% silver. It is a permitted standard in Norway and Finland and was the legal minimum for silver in Sweden until 1999, but it is not sterling silver, which requires 925.

• That the piece is sterling silver
• That the stamp is genuine or was applied by a control office
• The maker, age, country of origin, or value

1. 1Photograph the 830 together with every mark beside it: maker’s mark, town mark, date letter, or control mark
2. 2Use the surrounding marks to place the piece in one national system before reading the number
3. 3Ask for an XRF reading if a sale or insurance schedule depends on the silver content

What an 830 stamp claims

830 is a millesimal silver mark: 830 parts silver in every 1,000 parts of alloy, or 83.0 percent. The other 17 percent is a different metal that the stamp does not name. Compared with sterling, which is 92.5 percent silver, an 830 alloy holds less silver and more of that other metal.

Norway’s precious-metals regulation lets a silver fineness mark carry the letter S after the number, so 830S is the same claim written the Norwegian way. Finnish and Swedish marking rules also provide for town and year marks, so an older Nordic piece can show 830 beside a town mark and a date letter.

The number is a fineness claim, not a guarantee. It becomes stronger evidence when the marks around it, such as a registered maker’s mark or a control-office mark, belong to the same national system.

Why 830 is a Nordic standard

Norway: the current Norwegian regulation on precious-metal articles lists four silver standards, 999, 925, 830, and 800, and states that only articles in the permitted standards may be called silver.

Sweden: under the Swedish Act on Trade in Precious Metal Articles of 1986, silver articles had to contain 830 thousandths or more of fine silver. The current Act of 1999 lowered the minimum to 800 thousandths, and the government bill behind it confirms that official control stamping is voluntary.

Finland: the Finnish government decree on precious-metal articles lists 830 among the numbers permitted in a silver fineness mark.

Denmark: Danish law now sets the silver minimum at 800 parts per thousand and lets silver of at least 925 be marked simply Sterling.

A Nordic history makes 830 a likely reading, but the number alone does not prove where a piece was made. Read it with the maker’s mark and any town, date, or control marks.

Older Finnish silver: 813 and 813H

Finland used a lower silver standard before 830. The history of Finnish marking rules kept by Leimatoimikunta records that an 1891 law, in force from 1892, set 813 as the minimum silver fineness and its mark. From 1893 silver fineness marks were given in thousandths together with the letter H. The H was dropped from silver marks in 1973, and in 1974 the lowest permitted silver fineness became 830.

813H on a Finnish piece is therefore a claim of about 81.3 percent silver made under those earlier rules. It sits between the 800 and 830 standards and, like them, is not sterling.

830 outside the Nordic countries

Convention: the Hallmarking Convention lists 999, 925, 830, and 800 as silver standards that can carry its Common Control Mark. It also says that only five Convention standards are legal in every contracting state, and that for silver those are 925 and 800. A Convention-marked 830 piece has been tested, but 830 is not a legal standard in every member country.

United Kingdom: UK silver standards are 800, 925 (sterling), 958 (Britannia), and 999. 830 is not among them, so an 830 stamp is not part of a UK hallmark. The Birmingham Assay Office notes that hallmarking is a legal requirement in the UK for silver items weighing 7.78 grams and over.

United States: the FTC Jewelry Guides say the unqualified word silver can mislead unless an accurate fineness in parts per thousand comes immediately before it, as in “750 silver”. Sterling, sterling silver, and solid silver are reserved for metal of at least 925. An accurate U.S. description of an 830 piece is 830 silver, not sterling.

830 compared with 800, 925, and 958

The higher standards have their own pages: 925 sterling silver and 958 Britannia silver. For the checks that apply to any of them, see how to tell if silver is real.

• 800: 80.0% silver. The current silver minimum in Sweden and Denmark, and a legal standard in every Convention state.
• 830: 83.0% silver. A permitted standard in Norway and Finland and a Convention standard.
• 925: 92.5% silver, sterling. Required for the words sterling and solid silver under U.S. rules.
• 958: 95.8% silver, the UK Britannia standard.

Care, testing, and value

An 830 piece tarnishes like other silver. The Canadian Conservation Institute describes tarnish as mainly black silver sulphide formed by sulphur compounds in the air, and warns that every polish or chemical tarnish removal takes away some of the underlying silver. Clean gently and prevent tarnish rather than polishing hard.

Magnets and ice cubes do not measure fineness. If the silver content matters, ask for XRF testing, which the Birmingham Assay Office uses to analyze metal content, and ask which part of the piece was tested. Value starts from the verified silver weight, but maker, design, and condition can matter more.