This picture shows a coin worth half a Louis d'or, minted in 1643, during the reign of Louis XIII. To prevent the illegal practice of shaving slivers of gold from the edge of the coin, Jean Varin installed machinery in the Paris Mint that made perfectly round coins so that such damage could be readily detected. The obverse (left) features the king's head in profile and an abbreviated Latin inscription translating to 'Louis XIII, by the grace of God, King of France and Navarre', while the reverse (right) features four royal monograms (double "L"s surmounted by a crown) and four fleurs-de-lis, with the abbreviated Latin for 'Christ reigns, conquers, commands'. This coin is part of the National Numismatic Collection at the Smithsonian Institution's National Museum of American History.
Other Louis d'or coins: Louis XIV, Louis XV, Louis XVICoin design credit: Jean Varin; photographed by the National Numismatic Collection