Art Nouveau ring, silver, frieze with Liberty geometric motifs, carnelian agate cabochons and dragon veins, bezel set with a section of polished carnelian agate, signed, circa 1900
  
 A model of a ring by Delon, in low relief of two panthers, circa 1930, is reproduced in the book  Bijou Art Déco,  Sylvie Raulet, Éditions du Regard.