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Hallmarks for Platinum, Gold and Silver. 


A hallmark is a small symbol or number that appears on precious metal jewellery. If a jewellery piece weighs more than 1 gram, it must have a hallmark in the UK. The hallmark tells what type of metal the jewellery is made of, who made it, and where it was tested.

When jewellery is made, it's tested and marked with a hallmark. This helps to ensure the jewellery is made of the right type of metal and how pure it is.

The hallmark has symbols that show the metal's purity. For example, if it has 750 on it, that means the metal is 75% gold. This is like saying it's 750 parts out of 1,000. The hallmark also has a standard symbol called the common control mark (CCM), which shows that the jewellery meets certain standards. The CCM must be accompanied by another mark that shows the exact purity of the metal and a unique mark for each type of metal or its chemical symbol.


What is an Assay Office?


Assay Offices are independent organizations that test and hallmark precious metal jewellery in the UK. They have a long history, with the first Assay Office established in 1300 in London. These offices aim to guarantee the quality and purity of precious metal jewellery, providing consumers with peace of mind when purchasing.

Each Assay Office has its unique hallmark, which appears on jewellery items tested and approved. These hallmarks are recognized worldwide as symbols of quality and authenticity. Additionally, the offices provide educational resources and publish guidance to help consumers identify hallmarks and understand their significance.

In short, Assay Offices play a crucial role in maintaining the reputation and value of precious metal jewellery in the UK and beyond. Their hallmarks are a trusted symbol of quality for consumers and the jewellery industry.


What happens when jewellery arrives at the Assay Office?


Most of our jewellery receives a hallmark from the Birmingham Assay Office. Their video gives a greater insight into the daily work undertaken and the process of hallmarking precious metals. 

Another symbol on the hallmark shows which Assay Office tested the jewellery. For example, it could be in London, Birmingham, Sheffield, or Edinburgh.

The sponsor mark shows who was responsible for the hallmark, which could be a jewellery manufacturer or a retail jeweller. This mark has a unique combination of letters within a specific shape. Every piece of jewellery has a unique mark stamped or laser-etched onto it.

Some jewellery also has a date letter showing the year the hallmark was made. Most Assay Offices provide information to help people figure out the year of the hallmark. Remember that some jewellery is tested and marked with a hallmark after it's been made.

Typically, a jeweller submits a piece of gold, silver, platinum, or palladium for hallmarking after it's made. The Assay Office then tests the metal to make sure it's pure. The hallmarking process usually takes between one day and one week.

View more bespoke designs on our bespoke engagement ring page 

Gold Hallmarks.


Gold jewellery can be made in a number of different carat grades depending on the amount of pure gold used to make the item.

18ct White Gold is one of the most popular choices for jewellery. Contrary to popular belief it is harder wearing than 9ct Gold. Although more expensive, 18ct Gold makes a more durable choice for a lifetime's wear.

Assay offices hallmark gold across the full selection of metals. For example, 18ct white gold, 18ct yellow gold and 18ct rose gold. In addition, 9-carat and 14-carat variations.

Gold Date Stamps


Many items of jewellery feature a gold date stamp included with the hallmark to identify the year of hallmarking. The UK Hallmarking Act (1973) abolished the compulsory addition of date stamps. As a result, most jewellery hallmarked today lacks the date stamp within the ring. The appearance of the stamp can be used to identify the year by looking at a chart such as the one featured below. 

950 Platinum and the Platinum hallmark.


Platinum is considered the premium choice for jewellery. The colour of Platinum is naturally greyish-white and polishes to a beautiful mirrored finish, consistently coloured and hypo-allergenic. 

Platinum can pick up wear and scratches over time. Wear builds to a natural patina and is quite easily re-furbished to restore the mirror polish. All of our Platinum is described as 950 Platinum which means it is composed of 95% pure Platinum alloyed with 5% Cobalt (Engagement Rings.) 

For Wedding Rings most of our Platinum is 95% Platinum alloyed with 5% Ruthenium. Cobalt and Ruthenium improve the hardness of Platinum. 

Platinum is favoured by many buyers. It provides a naturally white metal, a third heavier than 18ct Gold with a substantial feel. It is 100% hypo-allergenic and is less malleable than Gold making it suitable for Diamond setting. It creates a perfect mirror polish and stands out as the rarest and most desirable of the precious metals.

Platinum version of the Bowery diamond bubble ring design


950 Palladium Jewellery and Hallmarks.

Read more about Palladium engagement rings and wedding rings


Palladium is a naturally white precious metal, much lighter in weight than both 18ct Gold and Platinum. Palladium has become a popular metal choice in recent years following the introduction of the Palladium hallmark. Over the last year, the price of Palladium has soared due to industrial uses and demands for this metal.


Palladium vs Platinum. 


Compared to Platinum, Palladium is around half the weight. It has many similar properties to Platinum but feels lighter. We always recommend Platinum above Palladium owing to durability. Both metals are naturally white, finished with a mirror polish or brushed satin effect. 

Choosing 100% Ethically Sourced Precious Metals.


If you are looking for a precious metal that is 100% ethically sourced, there are various options available. Most of our precious metals are from recycled sources, making any choice ethical. However, there are further choices benefitting communities of Artisanal miners in poorer areas of the World.

For ethical consumers, Fairtrade Gold provides the best option. Fairtrade Gold originates from areas Including South America and South Africa. You will discover the option of Fairtrade Gold across many of our products throughout this website. Introduced to Serendipity Diamonds in 2014, Fairtrade Gold is 100% traceable unlike most Gold within the jewellery industry.

Unlike Gold mined by large mining corporations, Fairtrade Gold comes from impoverished small-scale artisanal miners. Being part of the Fairtrade system ensures that miners receive a minimum price for the Gold they recover. They conform to meet standards set by Fairtrade and their own lives, working conditions and lives of their families and communities improve as a result. The premium paid for Fairtrade Gold goes towards improving communities and has an incredibly positive impact.


The Fairtrade Gold Stamp.


Fairtrade Gold can be positively identified by the addition of the Fairtrade stamp within the jewellery. On some jewellery, the Fairtrade symbol might appear as a laser engraved hallmark. We have added some examples of our Fairtrade hallmarked jewellery below by way of examples. .

Fairtrade Gold light court wedding ring Mottistone available from Serendipity Diamonds

Assay Office Markings on Jewellery.


Several UK Assay offices provide the service of hallmarking jewellery. The Assay Office responsible for stamping your hallmark may appear within your jewellery. Each Assay Office has its own symbol. The Anchor for Birmingham, a Lion for London, a Tudor Rose for Sheffield and a Castle for Edinburgh. 

Since 1972 the UK has been a signatory to the international convention on hallmarks. To explain, UK Assay Offices can apply the CCM (common control mark) observed by all member countries in the convention. Likewise, common control marks under the same convention applied in other member countries are recognised in the UK.


Useful Links for Hallmarking


We found the following hallmark tool for identifying your hallmark, well worth visiting if you can view marks within your jewellery.