Hallmarks and what they mean
Every piece of fine jewellery has a story and Hallmarks are a key part of that narrative. Have you ever wondered how to read a Hallmark? The tiny stamps indicate a piece’s metal type, purity, origin and authenticity. Understanding these marks not only ensures you are investing in genuine materials, but also connects you to centuries of British craftsmanship and the traditions behind every handmade, ring, bracelet, or necklace.
What is a hallmark?
A Hallmark is the official mark stamped on precious metal in order to certify its purity or whether it is genuine.
Precious metals used in jewellery are almost always an alloy of pure metal and another metal, to give a piece of jewellery durability and flexibility. UK regulations dictate that for the four main precious metals (gold, silver, platinum and palladium), all must have a minimum amount of the pure metal within them, in order to be classified as a ‘precious’ metal - this percentage of purity is described as ‘fineness’
What does a Hallmark show?
Hallmarks are generally set in a horizontal line, slightly less than 1.5mm in height. But it totally depends on the size of the item being marked, the size of the punches the jeweller has, for the assay office to use and also if the mark is also being used as decoration.
Sometimes I like to use the Hallmark on the outside of the ring, or bangle, for added interest. Here is one of my silver bangles I made for a commission, showing the Hallmark on the outside. I think Hallmarks are a really attractive addition to a piece of jewellery.
Full traditional hallmark
The Full Traditional Hallmark comprises five marks:
- Sponsor's mark - compulsory
- Traditional fineness mark
- Millesimal fineness mark - compulsory
- Assay Office mark - compulsory
- Date letter mark
Here are the 5 full marks on my bangle
There are three compulsory marks; the sponsors mark, the fineness mark and the Assay Office mark.
Sponsor / Makers Mark
This mark represents the registered company that submitted the jewellery for hallmarking. Every jeweller has their own unique mark. The Sponsor's Mark comprises, the initials chosen by that person, or company, inside a surrounding shield shape. The shield shape varies, and a minimum of two, and maximum of five initials must be included.
In my case, Catherine Hills, my makers mark is 'CEH ' shown in this image; the initials of my name, in a round ended rectangle.
Assay Office Mark
There are 4 assay offices in the UK, where every article of jewellery must be tested and hallmarked. Each office has a distinctive symbol, which allows the owner to trace their article back to where it was first tested.
Birmingham - represented by an anchor
London - represented by a Leopard
Sheffield - represented by a Tudor Rose
Edinburgh - represented by a castle
The Fineness mark
This mark denotes the content of precious metal within the jewellery item, expressed in parts per thousand. Each type of metal will have a number in a different shape shield.
The mark will always denote the lowest standard of alloy content found when testing, guaranteeing the quality of your jewellery will always be no less than the fineness described
The current standards for each metal are as follows (all describing the parts per thousand of pure metal.
This mark will be a number.
- Gold - 9ct (375), 14ct (585), 18ct (750) and 22ct (916)
- Silver - sterling silver (925) and Britannia silver (958)
- Platinum - 950
- Palladium - 500 and 950
Here is a 9ct gold fineness mark on my bangle.
Optional Hallmarks
Date letter mark
Every year on the 1st of January, a new date letter stamp is created, and at the end of the year this stamp is destroyed. Date letters became optional in 1999, so most modern items you will find in store now may not have this stamped inside. Because the font and shape of the stamp change every year, it’s possible to pinpoint when the article was assayed. Before the introduction of the Hallmarking Act 1973, the 4 UK assay offices labelled dates using different letters. Since the Act was introduced each Assay Office prints the same letters each year. Date letters are a great way to identify the age of a piece of jewellery.
The letter mark for assay in 2025 is an uppercase 'A'. In 2026, it is an upper case 'B' for 2026 and so forth..
Traditional fineness mark
In addition to the compulsory fineness marks, you may also see a traditional fineness mark. These marks are applied as standard at the London assay office, but are optional elsewhere as shown in the image.
Commemorative marks
These Hallmarks are applied to articles, in order to commemorate landmark national events. Commemorative marks are optional, but are also a useful indication of age, as each commemorative mark related to a date in time, often highlighted by a portrait.
Mixed metal marks.
Items are allowed to be made of more than one metal. They are marked with the lowest metal it is made from; ie. if its made out of silver and gold it will be assayed 'silver' but a 'part mark' can be added.
Part Marks
An additional mark can be applied to signify the more precious metals, which make up the item.
How the jewellery is marked
There are two options.
Struck
Handmarking is the most traditional method of hallmarking. It is carried out using a punch and hammer creating an impression by moving (forming) the metal. This hallmark will last a lifetime.
Laser
Laser marking is the most recent method of applying the hallmark. Laser Marks are made with either a fibre, lamp pump, or diode laser - all three are used across our offices. A very fine, high powered beam, vapourises the surface of the metal and etches on the Hallmarks. These marks are good for delicate thin items, which would be damaged, if struck with a punch and hammer.
Where my work is assayed?
I send my work to the London Assay Office at Goldsmiths Hall, which is a beautiful building. The Goldsmiths’ Company Assay Office is where hallmarking began; it was established in 1478, they have been testing and hallmarking precious metals for over 500 years.
The leopard’s head mark, of London, has been used by some of the finest craftsman in history and continues to be the mark of quality for many of the leading jewellers and silversmiths today.
For me, as a craftsperson and jewellery maker, jewellery Hallmarks are more than small symbols, they are a guarantee of quality, authenticity, and heritage. For anyone investing in fine or handmade pieces, recognising these marks helps you appreciate both the craftsmanship and the story behind each item. As a Kent-based artisan jeweller, I believe understanding Hallmarks enriches the experience of owning jewellery, connecting modern designs to centuries of British jewellery-making tradition and ensuring every piece is cherished for a lifetime.