Simplon medal, by N.G.A. Brenet, reverse side showing Mountain Spirit, bronze, diameter 41mm, 4mm deep, 1807. Obverse, head profile to right of Napoleon, artist Andrieu. Reverse, naked old man with beard, sitting crosslegged, behind him the Simplon Pass and Tunnel entrances, dated 1807

Copper alloys, such as bronze, have a range of pleasing colours ranging from salmon pink, through the reds and yellows of gilding metals and bronzes, to the green and silvery tinges of the high zinc and high tin alloys. Commemorative medals were often struck in bronze.