Making a mark that will last forever.


Perhaps forever is a little exaggeration, but typically silverware lasts for generations. We regularly work on restoring items that might be hundreds of years old. Which means we need to recognise, date and trace precious metal masterpieces to make sure we treat them in the correct way. This is why the hallmark is so important, but have you ever tried to read one?

Our mark consists of the same components as all hallmarks, defined by the London Assay Office. The Goldsmith’s Company dates back to 1327, and founded it’s first assay office in Goldsmith’s Hall in 1478 (hence the term hallmark). The hallmark is getting on for 700 years old and hasn’t changed much. So let us explain this important set of symbols using ours.

The first mark in the hallmark is the Sponsor’s Mark - also called the Maker’s Mark. Ours is GGM for George Grant Macdonald, the founder of Grant Macdonald London. It is usually the initials of the maker or the workshop of the maker, and ours was registered with the Assay Office London while our founder was a student in 1966.

The next mark is actually a symbol, there are a set of symbols to denote the precious metal used. Precious metals are often silver coloured and can be hard to differentiate, especially after a few decades have passed so the symbol can be critical. The heraldic lion represents Sterling Silver (94.2% pure) the Britannia represents Britannia Silver (95.84% pure). There are symbols for gold, silver, palladium and platinum too.



The next mark is called the Millesimal Fineness Mark and references the quality of the metal. It guarantees the metal is no less pure in parts-per-thousand than the mark indicates, although it might be higher purity in some cases depending on the alloy of precious metal originally used. It’s a little complex and requires testing at the Assay Office. The mark for Sterling Silver is 925, for Britannia it’s 958. Other metals have similar marks and help you work out the difference in terms of value between 9 carat gold (375) and 18 carat (750) which has almost twice as much gold content.

The next mark is the specific assay office mark. Our work is always marked with the leopard’s head of the London office. There are marks for the offices in London, Birmingham, Sheffield and Edinburgh. London’s leopard denotes the mark called the ‘King’s Mark’ first used by Edward 1 to authenticate gold and silver. Actually,  it’s not really a leopard but a ‘leo-part’ which is how they referred to the lion’s face in heraldry at the time - taking the lion from the Royal Arms of ‘three lions’ fame.

The final mark is the date letter. This isn’t compulsory, but a new one is set every year by the Assay Office, changing in typeface and case to make each year unique. All official date punches are destroyed at the end of the year so there can be no forgery. Finally there are occasional extra marks that denote a special event, usually an event like the coronation of a monarch or a jubilee, or the new millennium.

There are many assay offices worldwide, each with their own formats and traditions, so it takes some expertise and research to read them all. To the untrained eye, they are mysterious. To the master craftsman, they are akin to signing their work... and for future historians and auctioneers, they are a mine of information about the provenance and quality of the piece they hold in their hands. For more information on hallmarks, visit the Assay Office London website.

Share this post