A Belle Epoque Arc de Triomphe brooch, Cartier Paris, special order, circa 1919. Gold, platinum, sapphire cabochons, fancy-cut faceted rubies and emeralds, round old- and rose-cut diamonds, faceted and calibré topazes, onyx. 4.06 x 3.09cm. The sapphire cabochon represent the helmets of soldiers who paraded down the Champs-Élysées to celebrate victory in World War I on Bastille Day, 1919. Source: Cartier, 1899-1949: The Journey of a Style.