HallmarkingA hallmark is your guarantee that the silver and gold used to make your jewellery conforms to legal standards of purity. All silver items over 7.78g and gold items over 1g will have my sponsor mark and the required London Assay Office fineness marks laser engraved. 

Underweight silver items can be hallmarked on request at an extra cost . Please allow at least 4 weeks for made to order items requiring a hallmark to be completed. 

Find out more here-

https://www.assayofficelondon.co.uk/hallmarking/what-is-a-hallmark