Patterns from the Second Empire coinage reforms were produced in considerable variety during the 1850s as Napoleon III's government experimented with portraiture and module sizes before committing to production dies. The 1858 half-franc pattern sits in that developmental window, with Mazagran 925 distinguishing it from the regular Gadoury-listed circulation strikes by die treatment or edge detail — the specifics vary by example.
French pattern coins of this period were struck at the Paris Mint for official presentation and archival purposes, not trial use.
Patterns from the Second Empire coinage reforms were produced in considerable variety during the 1850s as Napoleon III's government experimented with portraiture and module sizes before committing to production dies. The 1858 half-franc pattern sits in that developmental window, with Mazagran 925 distinguishing it from the regular Gadoury-listed circulation strikes by die treatment or edge detail — the specifics vary by example.
French pattern coins of this period were struck at the Paris Mint for official presentation and archival purposes, not trial use.