Hallmarking is the oldest form of consumer protection for jewellery buyers, ensuring the authenticity and purity of precious metals like gold, silver, platinum, and palladium. This glossary provides key hallmarking terms, giving jewellers, collectors, and enthusiasts a comprehensive guide to understanding the essential marks and symbols that certify quality in jewellery.
A certified establishment that tests precious metals for purity and applies hallmarks. UK Assay Offices include London, Birmingham, Sheffield, and Edinburgh.
Also known as the “town mark,” this symbol indicates which Assay Office tested and hallmarked the item. For example, London uses a leopard’s head, Birmingham an anchor, Sheffield a rose, and Edinburgh a castle.
A grade of silver with a minimum fineness of 958 parts per thousand, symbolised by a seated Britannia figure in hallmarking.
A unit of gold purity; 24 carat represents pure gold, while 18 carat is 75% gold. Carat purity levels are represented by numbers in hallmarks (e.g., 375 for 9 carat, 750 for 18 carat).
An international hallmark under the Vienna Convention, allowing items to be sold across member countries without further assay testing. The CCM includes the millesimal fineness, a mark for the Assay Office, and a symbol for the metal type.
An optional mark that denotes the year an item was assayed, with different fonts and shapes used annually to indicate specific years.
Historically, this mark indicated that tax had been paid on gold and silver items. Though no longer in use, it helps identify antique pieces. For example, a monarch’s head was used in the UK to signify the duty mark on older items.
A compulsory numerical mark indicating the purity of the metal in parts per thousand, such as 925 for sterling silver and 750 for 18-carat gold.
Common symbols used in gold hallmarking include crowns for gold. In some cases, specific symbols or icons are used to differentiate purity levels.
A set of symbols stamped on precious metal items to indicate their purity, the Assay Office, and the sponsor. In the UK, the traditional full hallmark consists of the sponsor’s mark, the fineness mark, the Assay Office mark, and sometimes the date letter.
Legislation governing hallmarking practices, which varies by country. In the UK, the Hallmarking Act 1973 mandates hallmarking to protect consumers and regulate precious metal trading.
A mark applied to foreign-made items that have been assayed and approved by a UK Assay Office, ensuring they meet UK hallmarking standards.
A hallmark that allows jewellery to be sold across borders within countries that are part of the Hallmarking Convention without additional testing.
A modern method for applying hallmarks using lasers instead of traditional stamping. This technique is ideal for delicate or intricate items where stamping could cause damage.
A compulsory mark that shows the initials or symbol of the registered person or company responsible for submitting the item for hallmarking, enclosed within a unique shield shape.
A compulsory hallmark indicating the purity of a metal as a number out of 1000. For instance, 999 represents pure gold, while 916 represents 22-carat gold.
For items containing multiple metals (e.g., silver and gold), this standard shows the purity and proportion of each metal within a piece, with different sections marked with corresponding fineness symbols.
Marks applied to items made from more than one type of metal, indicating the metals present and their purities.
Introduced in 2010, this mark indicates the purity of palladium items, such as 500, 950, or 999 parts per thousand. Palladium is often represented by a Pallas head symbol.
Represented by an orb symbol, platinum hallmarks may also include purity indicators like 950 (95% platinum content).
A process where items are re-tested and re-marked if they are resold in a different country with different hallmarking standards or regulations. This is relevant for antique jewellery sold internationally.
While not a hallmarking term per se, scrap value is important in hallmarking, as hallmarks help determine the base material value of an item based on metal purity.
Sterling silver (92.5% purity) is represented by a lion passant in the UK, while Britannia silver (958 parts per thousand) uses the seated figure of Britannia.
The unique initials or symbol registered by the person or entity submitting the jewellery piece for hallmarking, enclosed in a shield or border unique to that sponsor.
Each sponsor’s mark includes a unique registration number or series that identifies the maker and is registered at the Assay Office. This number is helpful for tracing the origins of specific items.
A standard grade of silver, 92.5% pure (marked as 925), often symbolised by a lion passant in UK hallmarking.
The full hallmark set in the UK, which includes the sponsor’s mark, fineness mark, Assay Office mark, and potentially the date letter.
