5 Francs - Rainier III Piedfort Essai

Piéforts are deliberately struck at twice (or more) the standard planchet thickness, a practice the Paris Mint has used for centuries to produce presentation pieces for official approval and diplomatic gifting. This gold example from 1960 sits at roughly four times the weight of the standard circulation 5 Francs, consistent with a double piéfort rather than a single — the 41g figure in gold at 29mm leaves no other conclusion. Monaco's essai and piéfort programs of this period were produced in extremely small numbers, typically fewer than a hundred pieces, with exact mintages rarely formally published.