10 Things You Should Know About Jewellery Hallmarking

If you’re shopping for jewellery, it’s crucial you understand hallmarking, to understand exactly what metal you are getting.

Unfortunately all that glitters is not gold – and if you read the press, you’ll know that rogue jewellers exist, even in the UK.

Official hallmarking is the trusted way to guarantee that you are getting the correct purity of precious metals in your jewellery.

That’s why we visited the London Assay office where it all happens, to bring you this hallmarking guide – with video and photographs – to show you first hand how and why these tiny marks on your jewellery are so vital.

Entrance to the London Assay Office, one of the four locations where UK hallmarking is carried out
Entrance to the London Assay Office, one of the four locations where UK hallmarking is carried out

1. Hallmarking is the law in the UK
In Britain, all jewellery that is sold as having been made with gold, silver, platinum or palladium, must be hallmarked according to the Hallmarking Act 1973.

2. What is hallmarking?
A hallmark is a government seal that’s stamped onto precious metal objects, such as jewellery or silverware. The purpose of a hallmark is to certify the metal purity of the item. Only a UK Government Assay Office can apply a hallmark. Testing precious metals for purity is called “assaying”, hence the name.

Watch our video on hallmarking at the London Assay Office:

3. British hallmarking was established 700 years ago
The first Assay Office opened in London in 1327. This means that hallmarking is one of the earliest forms of consumer protection!

The London Assay Office, entrance hall
The London Assay Office, entrance hall

4. There are only four UK Assay offices
There are four Assay offices in Britain, located in London, Birmingham, Sheffield and Edinburgh.

5. Four precious metals are hallmarked
Gold, silver and platinum, and most recently palladium, must all be hallmarked. White and yellow golds must be further classified into 9K, 14K, 18K and 22K standards, and so on. Silver, platinum and palladium must also satisfy a percentage of purity to meet UK hallmarking requirements.

6. Hallmarking protects both consumers & jewellers
Compulsory hallmarking means that the public will always have a guarantee of quality. Likewise, legitimate jewellers’ trade is protected from unlawful competitors who might try to pass lower quality jewellery off as the “real deal”. Because it’s impossible to tell how pure a precious metal item is by simply looking at it, only official Assaying can guarantee standards.

Can you guess the precious metals in the below items? Click on the images to find out if you got it right!

Can you guess the metal these jewellery items are made of? Click on the images to find out!

Click here to view: Hallmarked jewellery items

7. Today both modern & traditional Assaying methods are used
Assay office laboratories now test precious metal purity using the latest technologies, including x-ray and laser analysis. However, many objects are still stamped by hand, exactly as they were 700 years ago. Click on the below photos we took during our visit to the London Assay Office to see hallmarking in action!

8. Only officially registered hallmarks can be used
Only jewellery that carries an officially registered British or international hallmark can be sold in the UK. A hallmark will usually include the Assay office town mark, together with 2-4 additional marks, such as a date letter, a metal standard symbol or a duty stamp. There are hundreds of registered hallmark elements. If in doubt, contact the International Association of Assay Offices for more information.

The Assay Office marks – the leopard's head of London, the anchor of Birmingham, the Yorkshire rose of Sheffield, and the castle of Edinburgh

9. It’s a criminal offence to misrepresent a hallmark
According to the Hallmarking Act, it’s an offence to claim that a piece of jewellery is made with gold, silver, platinum or palladium, unless it’s hallmarked as such. It’s also an offence to remove, alter, deface or counterfeit a hallmark.

10. The only exceptions to hallmarking law are items that weigh very little
The hallmarking law exempts precious metal objects that weigh under a certain number of grams. This could mean small jewellery items like stud earrings or pendants. Jewellery does not have to be hallmarked if it weighs under:

  • 1 gram for gold
  • 0.5 gram for platinum & palladium
  • 7.78 grams for silver

Would you like to know more about hallmarking? Contact us, we’d love to chat! Or visit the Assay office websites for London, Birmingham, Sheffield or Edinburgh for more information.

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UK hallmarked platinum and sapphire engagement ring from