• We're back with 15% OFF everything with offer code BACK
  • Orders shipped in 2-3 days
  • Join our mailing list for the latest offers
Handmade in Cornwall
Be inspired

Hallmark Stamp

All our solid sterling silver and 18k gold clasps are hallmarked at Goldsmith’s Hall in London.


Hallmarking consists of a series of marks applied to platinum, gold, palladium and silver. A complete hallmark consists of three compulsory punch marks:

  1. Our maker’s mark - BOING
    This states we are the company submitting items for hallmarking and are the manufacturer of the product.
  2. Traditional fineness mark (optional)
    This symbol shows the nature of the precious metal.
  3. Metal and fineness (purity) mark
    Different shapes are applied for each metal showing the purity content; in the case of our silver it shows 925 in an oval.
  4. Assay Office mark
    Showing where it was assayed, in our case Goldsmiths’ Hall, London. The four UK Assay offices are; London, Sheffield, Birmingham and Edinburgh.
  5. Date mark (optional)
    This is a symbol showing the year the item was assayed.


We are keen to be transparent and openly authenticate all our precious metals, this means our precious metal articles have been independently tested where legally required. By doing this we provide you with a guarantee that our precious metals conform to the highest legal standards of purity (fineness).


Goldsmiths’ Hall in London has been testing the quality of precious metals since 1327. In fact the word hallmarking itself refers to the Goldsmiths’ Hall where, from the 15th century, London craftsmen brought their work to the hall for assaying and marking.

Jewellery and Apparel
Copyright © 2022 All Rights Reserved
Boing Apparel Limited
Webiste designed by Underlined
BOING® is a registered trademark of Boing Apparel Limited, UK.