“Wanna buy some gold mate? It’s real, honest!”

How do you know? Well, in the UK at least, it will have to bear a hallmark to prove that it’s been tested by an independent third party. This is the role of the four Assay Offices that are based in London, Birmingham, Sheffield and Edinburgh.

The first of these was the London Assay Office and this was based at Goldsmith’s Hall, the headquarters of The Worshipful Company of Goldsmiths or the ‘Goldsmiths Company’ as it is more commonly known. The term ‘hallmark’ comes from the fact that the gold and silversmiths of London had to bring their wares to Goldsmiths Hall in order to have then assayed, or tested, and marked.

This was nothing new. The practice of testing and marking precious metals dates back to the 4th Century AD, where traces of quality marks are found on Byzantine silver but the process was formalised in the England in the Middle Ages and backed up by legislation since 1300 when Edward I enacted a statute requiring all silver to reach the Sterling standard of 925 parts per thousand. Anything that passed the test was to be marked with a leopard’s head to verify its quality. Edward III then granted a charter to the Worshipful Company of Goldsmiths in 1327 and hallmarking was, thereafter centred on Goldsmiths Hall and the Leopard became their mark and remains so today.

The Hallmark today consists of four elements. These are:

The Hallmark today consists of four elements. These are:
Maker’s mark:This tells you who made the piece as every maker has their own unique mark.
Standard markThis shows the standard in a number as an expression of parts per thousand.
The Office markShows which of the four Assay Offices marked the piece. (This is Sheffield).
Date markShows the date as a letter in a particular script and shield.

The four Assay Offices are, as you’d expect, based in the main jewellery and silverware producing areas in the UK. There also used to be offices in York, Newcastle, Chester, Exeter, Belfast and Glasgow so you may find other marks on old jewellery or silverware.

These days the London office still handles more work than any of the others but many manufacturers still like to use their local office so that the connection between where it was made and where it was marked is preserved.

Current Assay Offices.

Other marks

There are a variety of other marks that you might find on jewellery and silverware, for instance the lion that was used to denote sterling silver and the Britannia symbol for (funnily enough) Britannia silver. These have now been ‘standardised out’ and replaced by the number system but we can still opt to use them if we want to.
There are various other convention marks and marks for special occasions such as the Millennium and these can be used to add another level of meaning to a gift by marking the fact that a wedding, for instance, took place during a significant year.

How’s it done?

As manufactures we have to register with an Assay Office and get our own individual punches cut in order to strike our maker’s mark. Then we send the work away, usually at an early stage in the manufacturing process and they test it, mark it and return it to us.
We send it unfinished because the main method used is one called Cupellation which involves scraping off little bits of the metal and melting them in a special crucible or ‘cupel’. Various methods are used to draw off and eliminate the metals other than the one that you are testing for and, by weighing the sample before and after the process, the proportions of each can be determined.
If the piece passes the assay then it’s marked and returned with a few scrape marks to clean up, if it fails then they kindly destroy it for us and return it as scrap.

What you need to know
I could go on but this page is getting too long and I meant it to be a practical guide not a dissertation on the whole field. What you need to know, really, is this:

That it has been marked.

Everything over a certain weight should be marked if it is to be described as being made of a precious metal. Some pieces, especially earrings, may fall below the exemption weight but I would tend to mark them anyway. For most of my earrings I mark them on the actual earring post so as not to mar the appearance of the earring itself.

What the standard is.

Each metal has it’s standards and the tables below will show you what those standards are and what the numbers mean. Note that each metal has its own shield so that you can distinguish between them.


A few things to note:
For platinum and palladium, the normal standard in the UK is 950
For silver the normal standard is 925 or ‘Sterling silver’.
For gold, anything over 916, or 22ct, is very soft and it becomes less practical as a material for making jewellery. In some cultures, however, 990 or even 999 or ‘pure gold’ is used in preference, as the intrinsic value of the gold is the primary element in the piece rather than the ascetic.


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