I used to work in the Edinburgh Assay Office, and I learnt a lot about hallmarking while I was there. Some of which I’ve probably forgotten…
Here’s a summary of what I do know, and why it’s important for you.
A hallmark is a collection of marks which are stamped or lasered onto the surface of precious metal by an independent company. The independent assay office tests the metal to confirm that it is what the jeweller says it is, stamping it with a hallmark to confirm this.
Hallmarks are the earliest form of consumer protection being offered by assay offices round the country. This means that your piece of jewellery has been independently tested and you can read the hallmarks so that you know exactly what your jewellery is made from. So, for example, you’ll never get charged for 18ct gold but get gold plated silver… All items of Silver, Gold, Palladium and Platinum over a certain weight threshold require hallmarking. It also gives protection to the jeweller that their bullion company is giving them the metal they say they are!
The hallmark is usually a minimum of three legal marks. The Makers Mark, the metal/fineness mark and the assay office mark.
The maker’s mark and the assay office mark give your piece a unique identifier; no other jeweller or silversmith who is registered with that assay office will have the same mark. My maker’s mark is my initials JNC inside a chamfered rectangle. The fineness mark, is a number inside a shape. The shape denotes the metal type and the number is it’s parts per thousand. So a 925 inside an oval. An oval means silver, 925 means 92.5% silver which is also know as sterling silver, the most commonly used silver. However this mark alone or a 925 alone is not an independently verified hallmark, it must be combined with a maker’s mark and an assay office mark.
The assay office mark for Edinburgh, where I used to work and get my jewellery marked is a castle inside a complex shape. You can see it here on the dealer’s notice which you should always see at a jewellery stand, or in a jewellery shop as it’s also a legal requirement to display one of these if you’re selling jewellery. It also shows you each shape for the different metals.
There are also two optional marks which include the traditional fineness mark, for example silver in Scotland is the lion rampant, and gold is generally a crown. Finally there is the date letter. The font and the shape of this mark tells you which year it was hallmarked in as they continually run through A-Z. It misses out the letter i which could be mistaken for an L. Currently, in 2018, the date letter is a lower case t.
Here’s a couple of images of items I have had hallmarked. Click on them to see the larger image.
One is a sterling silver bangle in hallmarked in 2017 and the other a pair of silver and gold cufflinks hallmarked in 2018. You can see the numbers and shapes, but also how small the marks are!
You’ll see in the second image there is a 375 inside a chamfered rectangle after the hallmark, this is a part mark. The 375 is 37.5% and the chamfered rectangle means gold. It tells you that the item is sterling silver and has some 9ct gold present. This should be obvious gold, like on these cufflinks.
Only jewellery over a certain weight limit requires hallmarking. In silver this is 7.78 grams, Palladium and Gold are 1 gram, and Platinum is 0.5 grams. As a result a light silver ring, or cufflink, or earrings are often below the legal requirement to need a hallmark.
I get all my bespoke items hallmarked, despite the weight limits. I tend not to hallmark my “stock” items unless they’re over the weight limits. You can find out more practical hallmarking information here.
There are only 4 assay offices in the UK. London, Birmingham, Sheffield and Edinburgh. There used to be many more around the country. Therefore if you have antique hallmarked item, it could have been marked in another office. You can easily find out more about hallmarking by going to the websites of the different offices. The Assay offices are there to help you so don’t be afraid to ask if you want more information from them. Some of the larger offices have resources to help you identify the makers of pieces. Different countries have different rules and regulations over hallmarking.