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Hallmark Stamp


a. What is a Hallmark?

Precious metals are rarely used in their purest form, but are usually alloyed with other metals for the properties, such as durability, workability and flexibility, needed to produce a desirable jewellery article.

It isn’t possible to detect an article’s precious metal content by sight or touch. Therefore, it's a legal requirement in the UK to hallmark any item described as gold, silver, platinum or palladium by an independent Assay Office.

The hallmark guarantees the precious metal content of the item you’re buying, giving you complete reassurance.


b. What does a Full UK Traditional Hallmark consist of?

A Full UK Traditional Hallmark comprises three compulsory marks and two optional marks.

1. Sponsor's Mark (compulsory): This is the registered mark of the company that submitted the article for hallmarking.






 2. Fineness Mark (Compulsory): Tells you the precious metal content, expressed in parts per thousand.




3. Assay Office Mark (Compulsory): Tells you which Assay Office tested and hallmarked the article. There are four Assay Offices in the UK, each one holds its own hallmark symbol. 






4. Traditional Fineness Symbol (optional mark)





5. Date Letter (optional mark): Shows the year in which the article was hallmarked.




c. Are there any exemptions for Hallmarking?

Articles weighing less than the following will not carry a hallmark:

  • Gold weighing less than 1 gram
  • Silver weighing less than 7.78 grams
  • Platinum weighing less than 0.5 gram
  • Palladium weighing less than 1 gram


d. What is the International Convention on Hallmarks?

The International Convention on Hallmarks is an international treaty between contracting countries, which aims at facilitating the cross-border trade of precious metal articles.

UK is a signatory to the International Convention. This means that UK Assay Offices can apply the Common Control Mark (additional optional mark) which will then be recognised by all member countries in the Convention.

The member countries of the Convention are: Austria, Cyprus, Czech Republic, Denmark, Finland, Hungary, Ireland, Israel, Latvia, Lithuania, The Netherlands, Norway, Poland, Portugal, Slovak Republic, Slovenia, Sweden, Switzerland and United Kingdom.

For more information about the International Convention Marks, please visit Birmingham Assay Office website.


e. Where do we Hallmark our articles? How can our unique Sponsor's Mark be recognised?

Hallmarking is incredibly important to us at Ounce Jewellery. All our precious metal articles have been independently tested and hallmarked where legally required at Birmingham Assay Office. Our jewellery articles will carry our unique Sponsor's Mark (pictured below).