Hallmarking

For precious metals, a hallmark is a series of marks, applied by an independent assay office, that guarantees the metal's fineness and authenticity.

No, they do not. Sterling silver items weighing more than 7.78 grams must be hallmarked, but anything less than that does not need to be.  

Any pieces that have been hallmarked will have that noted in the description of the piece.

For more information, please check: https://www.edinburghassayoffice.co.uk/