Gold plated pieces are required to be hallmarked only if they use precious metal as their base metal and they fall under the required weight for an object to be hallmarked. Silver jewellery is often plated with gold. In this case, the jewellery must weigh more than 7.78 grams of silver. The Assay Office also remarks that “The gold plated layer must be of fineness of at least 375 parts per thousand and should not exceed 2 microns in thickness.