Practical applicability of alternative sort of coating of contemporary copper forgeries with use of mercury only (i.e. without use of another metal such as silver or tin) has been experimentally definitely proven. This undescribed way of amalgamation coating is based on simple dipping of a cleaned copper flan in mercury. In few hours, a stable silvery layer of the copper amalgam covers the copper surface. This kind of plating was most likely used by forgers in process of plating of the copper forgeries copying parvi of Wenceslas II at the beginning of the 14th century.