24K gold (999)
The metal is fine gold: 24 karats, marked 999 under the UK’s hallmarking rules.
How to read it
The FTC’s jewelry guides treat 24 karat as fine gold: the word gold on its own, with no karat figure, should describe only metal that is fine (24 karat) gold throughout. The UK’s Hallmarking Act lists 999 as its highest gold standard, struck as the figures 999.
Also searched as: 24K, 24 karat, 999 gold, fine gold.
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.
More jewellery marks
Sources
- 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, § 23.4(b)(1)
- 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
Last reviewed September 27, 2026 by Rory Hansen. How we research