999 (fine silver)
The metal is fine silver: 999 parts in every 1,000 are pure silver.
How to read it
Silver marks give the pure silver content in parts per thousand. The FTC’s jewelry guides ask for that figure before the word silver, giving 750 silver as their example. The UK’s Hallmarking Act lists four silver standards and the figures struck for each: 800, 925, 958 and 999, so 999 is the purest silver the Act marks.
Also searched as: .999 silver, 999 silver, fine silver.
A stamp is a claim about the metal, made by whoever struck it. This page says what each mark means under the rules that define it; it doesn’t test or value anything.
999 or 925?
999 is purer than 925 sterling silver, which has 75 parts in every 1,000 of other metals.
More jewellery marks
Sources
- Hallmarking Act 1973, Schedule 2: Approved Hallmarks, Hallmarking Act 1973 (c. 43), Sch. 2, legislation.gov.uk (The National Archives), Sch. 2, Pt. I, para. 2
- Guides for the Jewelry, Precious Metals, and Pewter Industries (16 CFR Part 23), 16 CFR Part 23 (1 January 2021 edition), Federal Trade Commission, published by the U.S. Government Publishing Office, § 23.5(b)(1)
Last reviewed September 27, 2026 by Rory Hansen. How we research