When used in relation to jewellery, a hallmark generally refers to a mark on certain metal items that certify that noble metals have been used to make them. Noble metals can include platinum, gold, silver, or palladium. Jewelers will always check any piece of jewellery for a hallmark because this little mark can tell them a lot about, they piece they are inspecting or repairing.

Hallmarks are stamps that are found on pieces of precious metal, it not only shows the composition and purity of the metal but also includes information about the origin of the jewellery. The practice of hallmarking jewellery dates back to 1327 in London when the first Assay Office was opened.

Jewellery will have two types of marks on them – a hallmark and a maker’s mark. The hallmark refers to the purity of the piece and the metal used while the makers mark indicates the origin of the jewellery. A true hallmark has both marks present, a makers mark on its own is not a hallmark.

When a piece of jewellery has a hallmark stamp it is a guarantee the minimum precious metal content in the piece of jewellery. Jewellery makers or an assays office can apply the stamp, there are four Assay Offices in and around the UK, they located in London, Birmingham, Sheffield, and Edinburgh.

Not all precious metals are required to have hallmarks. In the UK, the law states that only gold, platinum, silver and palladium need to receive this stamp. Gold has to be hallmarked as 9K, 14K, 18K, 22K while silver, platinum, and palladium must all meet UK hallmarking requirements.

The stamps are applied it two different ways. Assay offices have laboratories that use lasers and x-rays to analysis the piece of jewellery but there are many objects that do have the stamp applied by hand, like it was originally done.

When you buy a piece of jewellery that has been stamped with a hallmark you can be assured that you are buying a quality piece of jewellery. This gives you peace of mind that the piece of jewellery you are being sold, is in fact what the jewellery or jewellery store says it is. Hallmarks also protect the jewelers from competitors who are trying to sell jewellery that is of an inferior quality.

Common hallmark stamps

Stamp Precious Metal Composition
10K 10 karat gold 41.6% gold, 58.4% alloy
585 14 karat gold 58.5% gold, 41.5% alloy
950PD Palladium 95% palladium, 5% alloy
Plat Platinum 95% platinum, 5% alloy
925 Sterling silver 925.5% silver, 7.5% alloy

 1.The sponsors markis the mark of the person/company who sent the piece to be hallmark. This is most commonly the importer, wholesaler, or manufacturer but it can also be individuals. Before you can obtain this mark, you have to register with your local assay office.

2.The Standard Markis the mark of purity in the metal. It is measured in parts per 1000 and must be at least 750 parts per 1000 to receive the mark.

3.The Assay Office Markis the mark that shows which assay office tested the item. Each office in the UK has a different symbol making it easy for you to see where it was marked.

4.Date lettersare optional, letters are used to show the years, for example 2011 is marked with an m, 2012 is n and so forth.

5.Traditional marksare also optional but still used on some jewellery produced in the UK. These can include symbols like a crown for gold.

6.Commemorative marksare used on pieces that have been designed to commemorate a specific event like the Coronation or Golden Jubilee.

Countries like the United States do not require their makers to stamp their jewellery at all. While many jewellery makers do stamp their pieces, it does mean you have no way to check the authenticity of pieces bought from those countries.

Investing in an expensive piece of jewellery is big decision and whether you are buying it as wedding ring or as an anniversary gift or for some other special occasion you want to know that the piece of jewellery you are buying is authentic and is actually gold, silver or platinum. Hallmarks offer some assurances that the piece of metal you are buying has been checked and verified to contain the metals it says it does.