United Kingdom
Compulsory independent assay, and a lower legal floor for platinum and silver than the United States. An 850 platinum piece lawfully hallmarked in London could not be sold as unqualified "platinum" in the US.
| Property | Value | Authority |
|---|---|---|
| Minimum fineness to sell as "gold" | 375 parts per thousand (9 carat) is the lowest legal standard. The recognised gold standards are 375, 585, 750, 916.6, 990 and 999. [1] Contrast the United States, which has no minimum at all under the current FTC Guides. | Sch. 2 Pt. I para. 2 |
| Minimum for "sterling silver" | 800 is a legal silver standard in its own right; sterling is 925. Recognised silver standards are 800, 925, 958.4 and 999. [1] An 800 British article is lawfully marked as silver but is NOT sterling. US law recognises only 925 (sterling) and 900 (coin silver). | Sch. 2 Pt. I para. 2 |
| Minimum for unqualified "platinum" | 850 is the lowest legal platinum standard. Recognised standards are 850, 900, 950 and 999. [1] The sharpest US/UK divergence: 16 CFR 23.6(b)(3) requires 950 before "Platinum" may be used unqualified in the United States. | Sch. 2 Pt. I para. 2 |
| Hallmarking compulsory | Yes [1] Independent assay before sale, as opposed to the US model of seller disclosure policed after the fact. The same stamp carries a different guarantee. | Hallmarking Act 1973 generally |
| Assay authority | Four UK assay offices, each with its own town mark: London, Birmingham (an anchor), Sheffield (a rose) and Edinburgh (whose silver mark is a lion rampant rather than the lion passant used elsewhere). [1] | Sch. 2 Pt. I paras. 1 and 3 |
| Vienna Convention (CCM) member | Yes [2] One of the 22 contracting states. A UK hallmark carries the Common Control Mark and must be accepted in the other 21 states without re-assay. Full list as at 15 December 2023: Austria, Croatia, Cyprus, Czech Republic, Denmark, Finland, Hungary, Ireland, Israel, Italy, Latvia, Lithuania, Netherlands, Norway, Poland, Portugal, Serbia, Slovak Republic, Slovenia, Sweden, Switzerland, United Kingdom. | — |
Sources
- Hallmarking Act 1973, Schedule 2 (standards of fineness and marks) — The National Archives / legislation.gov.uk (Hallmarking Act 1973, Sch. 2)
- Convention on the Control and Marking of Articles of Precious Metals — Contracting States — Standing Committee of the Hallmarking Convention (Vienna Convention on Hallmarks, Contracting States list)