What is jewellery hallmarking? A simple guide to understanding hallmarks
- Hannah Baker and Deana Baker
- Mar 5
- 5 min read
Updated: 19 hours ago
When purchasing jewellery or precious metal items, we want to know that we are investing in a genuine, high-quality piece. One of the most reliable ways to ensure this is through hallmarking.
What is Hallmarking?
A hallmark is an official seal of quality stamped on jewellery. It’s a legal UK requirement that certifies the purity of silver, gold, platinum, or palladium*. It provides buyers with reassurance. A guarantee that their jewellery is the real deal, not fake or counterfeit.
*I work predominantly in silver and gold; these are the hallmarks I will cover below.
A hallmark typically appears as a series of small symbols stamped on precious metals, these include:
Numbers: Indicating the composition of precious metals within the piece, e.g. 925 or 375 (more on these below).
The manufacturer or jeweller's mark: This shows who made the piece. You will know a product is mine when you see my initials, 'DB'.
The hallmarking location: Identifies the location where the metal was tested and certified. Different countries have different rules. As I'm based in Britain, I use British standards through the Assay Offices: London (Leopard’s Head), Birmingham (Anchor), Edinburgh (Castle), Sheffield (Rose). The London Assay Office website explains more about this.
My hallmarking assay is London. Commemorative mark: For special occasions (optional), e.g.
King Charles Coronation (2023)
Queen Elizabeth II’s Jubilees (1977, 2002, 2012 and 2022)
Millennium (2000)
Date letter (Optional) – Some countries include a date letter that signifies the year of assay. This is true of the UK, and I always apply the full traditional hallmark, including the date letter.
Traditional fineness symbol (UK-specific, optional)
Symbolic representation of the metal, I also provide this:
Lion passant for sterling silver
Crown for gold
Orb for platinum
How to identify a Hallmark
To verify a hallmark on a piece of jewellery or a precious metal item:
Use a magnifying glass to examine the symbols stamped on the item.
Compare the marks with official hallmarking guides.
If unsure, consult me, another professional jeweller, or the London Assay Office -- they will provide an opportunity to trace its origins via their website.
When did hallmarking begin?
The practice of hallmarking dates back centuries, though sources vary on when exactly. Historical artefacts have long featured marks and symbols on precious metals. However, many may have been decorative, or even symbolic. Not technically hallmarks as we know them today.
The French cite that under King Louis IX in 1260, a book of trades was written to regulate the guilds. However, in 1300, England established the Goldsmiths’ Company Assay Office.
Historically, UK hallmarking laws were famously vigilant. If metals didn't meet the required standards, they were destroyed. The rules aren't so tough now. Although this may seem harsh today, it has rewarded The Assay Office with the highest global honour. Their hallmarks were a guarantee.
Since 1701, 10 Assay Offices have existed across the UK. Today, only the four above-mentioned UK Assay Offices remain. Over time, hallmarking laws have evolved around the world, becoming a reliable, recognised system for verifying precious metals.
Understanding the different types of gold and silver hallmarking
Many people do not realise that precious metals are not crafted entirely from 100% pure silver and gold. This is because silver and gold alone are too soft; they simply are not durable enough alone. For this reason, they are combined with other metals, typically zinc or copper. This forms a stronger alloy, making them suitable for daily wear.
In the UK, if precious metals weigh over a certain amount, they must legally be hallmarked according to the Hallmarking Act of 1973. For gold, it's over 1g and for silver, it's over 7g (quite heavy). This is due to the high cost of Hallmarking, meaning it is not commercially viable on smaller pieces of silver jewellery.
However, a drawback to this is that you cannot mark the piece, which doesn't give it authority. That being the case, I ensure all my silver and gold jewellery, both over and under 1g, comes with a Hallmark. You can always be assured of the quality.
925 Sterling Silver
925 Sterling Silver is made from 92.5% silver and 7.5% alloys, giving it strength and increasing the lifespan of jewellery. This is the most commonly utilised silver hallmark I handle, which gives off a cool, white hue with slightly warm undertones. When polished, it is highly reflective, offering a striking modern finish.
Other silver hallmarks include: 800 (Sterling), 958 (Britannia), 999 (fine silver), I don't offer these hallmarks as they are too soft for jewellery. 800 is more commonly used in silverware due to its durability. It can be used in jewellery, but rarely is.
9ct Hallmarked Gold
9ct Hallmarked gold contains 37.5% pure gold and 62.5% alloys, hence ‘375’ stamped on the gold. It is tough and highly durable, with a softer gold colour that many people prefer. Interestingly, 9ct gold was popularised during the war, as a more affordable option for wedding rings.
18ct Hallmarked Gold
18ct Hallmarked gold contains 75% pure gold and 25% alloys, hence ‘750’ stamped on the gold. Due to the higher gold content, 18ct Gold has a much richer gold colour compared to 9ct Gold.
Other gold hallmarkings include: 14ct (585), 22ct (916) and 24ct (999). I can reimagine in all of these carats except 24ct as it is very soft and not advised for jewellery. I typically remodel in 9ct and 18ct, these are the most common in the UK.
Mixing your jewellery's various hallmarked metals
If you have a selection of different hallmarked pieces, you may be wondering how it is possible to combine these, whilst keeping the high-quality precious metals of certain pieces.
As my day-to-day requires reimagining sentimental jewellery, a client may come to me with, for example, 9ct, 14ct and 18ct, to combine into a new piece.
When mixing them, l will get them to the closest hallmark they can be. Therefore, if we've got a lot of 18ct, I'll suggest we only use the 18ct, to keep it 18ct. Or if it's mainly 9ct, then I'll suggest we add a little extra gold to ensure it's hallmarked at 9ct. This way, you'll be able to mix the golds and still ensure a certain percentage of hallmarking.
An example of this is when my client Gill came to me with a mixture of 9ct and 22ct gold pieces. I suggested making her ring (shown below) in the two 22ct gold bands alone. We then saved the 9ct gold to create her daughter's rings.
Why Hallmarking is important
Understanding hallmarking symbols is especially important if you value authenticity and quality craftsmanship when purchasing jewellery. Hallmarks are your trusted guide. They confirm the jewellery meets recognised industry standards, assuring you of its precious metal content and protecting you from substandard or counterfeit items. It also reflects the maker's dedication to transparency and ensuring lasting quality.
So, next time you’re choosing a piece of jewellery, take a closer look at its hallmark, a small but powerful mark of integrity, value, and trust.
Resources for Hallmarking
