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A Guide to Hallmarks and Precious Metals


Read our guidance on hallmarks and precious metals. From common markings in jewellery to pro's and con's of different precious metals, our guide offers useful guidance for anyone purchasing jewellery. 


Choosing your precious metal


Before you purchase an item of jewellery, you will need to decide which precious metal to choose. There are several differences making each choice suitable depending on your requirements. The information below provides guidance on various aspects of Gold, Platinum and Palladium and the hallmarks associated with each precious metal. 


What is 18ct Gold?



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 is more durable over a lifetime. All of our 18ct Gold jewellery commissions include a hallmark with the number 750. This represents 75% pure Gold content. Regardless of the colour (white, yellow or rose) all 18ct Gold contains 75% pure Gold. 

18ct White, Yellow and Rose Gold 


18ct Yellow Gold is 75% pure Gold, hallmarked with a 750 stamp to denote this purity. For Engagement Rings, White Gold settings are popular above Yellow Gold bands to complement Diamond colour. 18ct Yellow Gold has recently risen again in popularity as alongside the ever popular White Gold version of this metal. 

18ct Yellow Gold is a blend of alloys. Engagement Rings typically contain 75% Gold, alloyed with Silver (16%) and Copper (9%).

18ct Yellow Gold is harder wearing than 9ct Yellow Gold. Many people assume that since pure Gold is too soft for jewellery, alloys with more impurities will be harder. 18ct Gold is actually harder than 9ct Gold and is recommended for greater durability with better hypo-allergenic properties compared to 9ct Gold. 

Did you know we can create 18ct Yellow Gold rings with Platinum settings? Contact us for a personal quote. 

Pro's and Con's of 18ct White Gold


There are pro's and con's when it comes to buying 18ct White Gold. Owing to the 75% Gold composition, 18ct White Gold is naturally straw-white in colour. The application of a white Rhodium plating gives 18ct White Gold its final colour. Some buyers express disappointment when the plating begins to wear—revealing the natural metal colour underneath. Although easily re-finished at any time, we recommend 950 Platinum for anyone worried about Rhodium wearing away from their jewellery. By comparison, Platinum retains its true colour, but dulls over time as scratches build. 

18ct White Gold version of the Bowery diamond bubble ring design


What is 18ct Rose Gold?


18ct Rose Gold has a warm copper colour. It is a beautiful alternative to the popular White and Yellow Gold options. 18ct Rose gold has more of a pinkish hue compared to 9 carat Rose Gold which is closer to the colour of Copper by comparison. 

Most of our jewellery designs can be crafted in this alternative choice of precious metal. Just like White and Yellow versions, all 18ct Rose Gold is composed of 75% pure Gold, alloyed with 4% Silver and 21% Copper giving the distinctive coppery colour to this precious metal. You will see the same 750 hallmark within each item of 18ct Rose Gold jewellery. This denotes the 75% purity of Gold within the item.  

Rose Gold works very well with both white and brown Diamonds, and is a popular choice for many vintage styled rings. Our Wedding Rings can be created in 18ct Rose Gold in both Men's and Ladies styles with further engraving options available for most ring designs. In addition, we create designs with a combination of 18ct Rose Gold adjoining a Platinum setting. 

18ct Rose Gold diamond cluster ring crafted by Serendipity Diamonds (see Daisy ring design for more details)

18ct Rose Gold Hallmarks


The photograph below shows one of our bespoke diamond engagement rings, crafted entirely in 18ct Rose Gold. You will see the 18ct Rose Gold 750 hallmark appearing next to the personalised engraving applied within the ring. 

View more bespoke designs on our bespoke engagement ring page 


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.

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 has always been a less desirable choice than Platinum—more cost-effective. This has now shifted and Platinum is a more desirable and affordable choice compared to Palladium. 


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. Our highest recommended choice is Fairtrade Gold. 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 incredible positive impact.

The Fairtrade Gold Hallmark


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


Within the UK there are several Assay Offices. 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. 

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.