UK hallmarks are assigned by the Assay Offices, of which there are currently four: London, Sheffield, Birmingham and Edinburgh. Modifications to the 1973 Hallmarking Act in 1999 changed the way articles made of precious metals are hallmarked. The UK hallmark now comprises a minimum of three compulsory symbols: a makers (or sponsors) mark; a purity mark; and the assay office mark.
The compulsory Assay Office marks appear as follows:
London: A leopard's head
Sheffield: A rose
Birmingham: An anchor
Edinburgh: A castle with 3 turrets
The compulsory purity marks appear as follows:
An oval disc with one of the following numbers inside:
800 for 80% silver content (often called Continental Silver)
925 for 92.5% silver content (often called Sterling Silver)
958 for 95.8% silver content (often called Britannia Silver)
999 for 99.9% silver content (often called Fine Silver)
The compulsory maker's or sponsor's mark vary and appear as one more letters within a shield.
There are other marks (known as Voluntary Marks) that can be applied to the item. The following list explains some of them:
Date mark: Curently a single letter within an octagonal shape. The letter for 2007 is a lower-case 'h'
Common Control Mark: A set of scales with a purity number (eg 925) set in the middle. This is an international mark.
Commemorative Marks: These vary, depending on the occasion (eg Queen's Head for her Golden Jubilee)
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