Gold Hallmarks

Gold Hallmarks Explained: What They Mean and How We Check Our Gold

When you buy second-hand gold jewellery, one of the first things you may look for is a hallmark. These tiny marks are easy to miss, but they can tell you a lot about a piece of jewellery, including the metal it is made of, its purity, and where it was tested.
At SHJ by Hatton Garden Metals, every piece we sell is checked carefully before it reaches our customers. As a family-run business with generations of experience in precious metals, we know how important it is to buy jewellery with confidence. That is why we inspect, test, and authenticate our gold, so you can enjoy genuine second-hand jewellery at exceptional value.

What Is a Hallmark?

A hallmark is a set of official marks stamped on precious-metal jewellery. In the UK, hallmarks are applied by an Assay Office and provide an independent guarantee of the metal’s purity. They are used on gold, silver, platinum, and palladium items over certain weight limits.
Precious metals are usually mixed with other metals to make them stronger and more wearable. You cannot reliably determine a gold piece's purity just by looking at it or holding it, which is why hallmarking exists. It helps protect customers by confirming that the item is genuinely what it is described as.

What Do Gold Hallmarks Mean?

A UK hallmark normally includes three compulsory marks:

1. The Sponsor’s Mark

This shows who submitted the item for hallmarking. It is usually made up of initials within a specific-shaped shield. Although people often call this a “maker’s mark”, it does not always mean the person or company physically made the piece. It identifies the registered person or business responsible for submitting it.

2. The Metal and Fineness Mark

This tells you the metal type and purity. Gold purity is shown in parts per thousand. For example:
375 means 9ct gold
585 means 14ct gold
750 means 18ct gold
916 means 22ct gold
So, if a ring is stamped 375, that means it contains 375 parts gold per 1,000 parts metal, which is 9ct gold. The fineness mark is one of the most useful parts of a hallmark because it tells you what quality of gold you are looking at.

3. The Assay Office Mark

This shows where the item was tested and hallmarked. The four UK Assay Offices are London, Birmingham, Sheffield, and Edinburgh. Each one has its own mark, such as the leopard’s head for London or the anchor for Birmingham.

What About Date Letters?

Some pieces also have a date letter. This can help identify the year the item was hallmarked. Date letters are now optional, but they can be especially interesting on vintage and older jewellery because they add more history to the piece.
This is one of the reasons we love second-hand jewellery. A hallmark is not just a technical detail; it can be part of the story. Some pieces have already lived a full life before they arrive with us, and many were close to being melted down before we saved them.

Does Every Gold Item Need a Hallmark?

Not always. In the UK, precious metal items below certain weight thresholds do not usually need to be hallmarked. The current exemption weights are:
Gold: under 1 gram
Silver: under 7.78 grams
Platinum: under 0.5 grams
Palladium: under 1 gram
If a precious metal item is over the legal weight threshold and is being sold as gold, silver, platinum, or palladium, it should carry a recognised hallmark unless another legal exemption applies.
This is why proper checking matters, especially with second-hand jewellery. Some older, delicate, repaired, or imported pieces may need a closer look from an experienced team.

Is a Hallmark Enough?

A hallmark is very important, but we do not rely on it alone.
Over time, jewellery can be resized, repaired, altered, or worn. Sometimes marks are faint. Sometimes a piece may have a stamp that looks convincing but is not a full legal hallmark. For example, a simple “375” or “925” stamp on its own is not always the same as a complete Assay Office hallmark.
That is why our checking process goes further.

How We Check and Test Our Gold

At SHJ by Hatton Garden Metals, every piece is checked before it is listed for sale. Our team handles large volumes of gold and jewellery through Hatton Garden Metals, giving us the experience to recognise quality, spot issues, and select the best pieces to save from the melt pot.
Our process includes:

Hallmark Inspection

We start by looking for the hallmark and carefully reading the marks. We check the fineness mark, Assay Office mark, sponsor’s mark, and any additional marks that may provide more information about the piece.

Visual Inspection

We inspect the item for condition, wear, repairs, sizing marks, solder joints, plating, damage, and anything that needs further checking. This is especially important with second-hand jewellery because every piece has its own history.

XRF Testing

Where needed, we use XRF testing to help identify the metal content. XRF is a non-destructive testing method, meaning it can analyse the surface of the item without cutting into it or damaging the jewellery.

Acid Testing

Acid testing can also be used to help confirm gold purity. This is a traditional method used in the precious metals trade and can be useful when hallmarks are unclear, missing, or need supporting evidence.

Expert Assessment

Finally, our experienced team reviews the piece as a whole. We are not just checking whether something is gold. We are deciding whether it is good enough to be sold through SHJ. We keep the best pieces, authenticate them, and offer them to our customers at excellent value.

Why This Matters When Buying Second-Hand Jewellery

Buying second-hand jewellery should feel exciting, not uncertain. A good piece of second-hand gold can give you the same beauty, quality, and wearability as a new item, often at a much lower price.
The difference is trust.
When you buy from SHJ, you are not buying an unchecked item from an unknown source. You are buying from a family-run business with deep precious metals expertise. Every piece has been selected, checked, and, where possible, saved from the melt pot.
That means you can shop smarter. You can find genuine gold jewellery, often one-of-a-kind, without paying the typical high-street prices.

The SHJ Difference

We believe great jewellery should not be melted down just because it is second-hand. Many of the pieces we see still have years of life left in them. Some are vintage. Some are classic. Some are unusual. Some are simply too good to scrap.
So we rescue the best pieces, check them properly, and offer them at some of the best prices in the UK.
When you understand hallmarks, you understand more about what you are buying. And when you buy from SHJ, you also know that the piece has been checked by people who understand gold inside out.

Final Thoughts

Hallmarks are small, but they tell a big story. They help confirm the purity of precious metal, show where a piece was tested, and sometimes even reveal when it was hallmarked.
But at SHJ, we go beyond simply reading the stamp. We inspect, test, and authenticate our jewellery so our customers can buy genuine second-hand gold with confidence.
So, the next time you see a tiny set of marks inside a ring, bracelet, pendant, or chain, you will know they are more than just symbols. They are proof, history, and part of the reason second-hand jewellery can be such a smart buy.
Explore our latest checked and authenticated second-hand gold jewellery today, and find a piece that was too good to melt.
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