Hallmarking laws date from 1300 in England when Edward I introduced the testing and marking of precious metals to offer protection to those buying or selling them. The laws originally applied to silver, were soon extended to include gold and now also apply to platinum and palladium. It is a legal requirement in the UK that any item described as one of these metals must be hallmarked unless it falls below the mimimum weight threshold (7.78g for silver, 1g for gold and palladium, 0.5g for platinum).
For precious metals to be suitable for use in jewellery it is necessary to alloy them with other metals to increase their strength. Once alloyed it is often impossible to tell how much of the precious metal is present without specialist testing, so hallmarking is important to ensure that anyone either buying or selling an item can be confident that it is as described. Concerns about whether a precious metal item may have been falsely described go as far back as the story of Archimedes’ ‘Eureka’ moment in Ancient Greece. He was asked to check whether a crown produced for Hiero of Syracuse had been made from pure gold (as stated) or was a mixture of gold and silver (which it was). His famous exclamation came when he realised that he could work out the volume of the crown by measuring how much water it displaced in a bath, and using this information calculate the density which would vary depending on the materials used. Methods of testing have moved on since then but the reason for testing remains the same.
A hallmark proves that an item reaches the minimum requirements to be described as the precious metal it is marked as. For example, gold will be stamped to indicate whether it is 9ct, 14ct, 18ct or 22ct which are the recognised standards of fineness in the UK. For 9ct the metal must contain 375 parts per thousand gold; if it has less than this then it cannot be hallmarked gold at all. It will be marked as 9ct if it contains from 375 to 584 parts per thousand gold as each standard is best thought of as a bracket rather than a precise amount. Once it reaches 585 it will be marked 14ct, then 18ct from 750 and 22ct from 916. The silver cross above has a '958' on the right arm to indicate that it is Britannia silver with a fineness of 958 parts per thousand silver.
Initially only the Wardens of the Company of Goldsmiths in London were empowered to conduct the testing and marking of precious metals. In addition to indicating the fineness of the metal, the item would be stamped with a sponsor’s mark and a date letter. The sponsor’s mark ensures traceability and is individual to the person or body who submitted the piece for hallmarking (usually the designer, manufacturer or retailer). Nowadays this is their initials enclosed in a distinctive shaped surround and it is especially helpful if an item needs to be reproduced or replaced. The silver cross has our own 'PA' mark at the top.
The date letter was originally introduced as a means of identifying the assayer. It is now most helpful in allowing people to date their jewellery and understand the history of family pieces. The style of letter will correspond to a specific assay office and alphabet meaning it can be compared to a reference book and identified in most cases. However, a date letter is not compulsory so not all pieces will have one.
It was not until 1773 that additional hallmarking services were made available outside of London with the founding of the Birmingham and Sheffield Assay Offices. Although others have existed at various times in the intervening period, today there are four Assay Offices: London, Birmingham, Sheffield and Edinburgh. These are highly respected and independent bodies who carry out hallmarking for manufacturers and retailers throughout the UK. Every item is given a mark to indicate which Assay Office carried out the hallmarking. Current marks are a leopard’s head for London, anchor for Birmingham, rose for Sheffield and castle for Edinburgh. On the silver cross the Sheffield rose can just be made out at the bottom.
The antique ring above still has very clear assay marks and the anchor second from right demonstrates that it was assayed in Birmingham. This information used in conjunction with the letter 'x' next to it allows us to date the ring to 1897. The crown and '18' show that the ring is made from 18ct gold; nowadays a '750' would be used to indicate the fineness of the metal. At the far left is the sponsor's mark.
Only the sponsor’s mark, fineness mark and Assay Office mark are compulsory. A date letter and additional symbol such as a crown for gold or orb for platinum are voluntary and therefore not always present. The Britannia symbol can be seen on the left arm of the silver cross. Additional marks may be added for special occasions, such as the millennium mark which was added to pieces assayed in the year 2000. This can be seen in the centre of the silver cross.
Recent developments in hallmarking include the introduction of laser marking which has made hallmarking small, hollow or curved items much easier, and changes in the law allowing mixed metal pieces to be hallmarked separately on individual sections. This change is especially important as it allows for more clear and accurate marking of pieces such as rings with gold bands and platinum settings or watches made with a combination of base metal and gold.
If you would like help interpreting the marks on a piece of jewellery or have any questions about hallmarking then our jewellers will be happy to help in the showroom or you can get in touch via telephone on 0114 266 9253 or email firstname.lastname@example.org