From the end of the 19th century, jewelry became an important vector of formal experimentation and plastic innovation of its time, thanks to the development of knowledge of stone, cutting and setting techniques. Books and exhibitions allow us to highlight this leading decorative art which accompanies Romanticism in its final stages before adopting the emerging Art Nouveau repertoire. The landscapes of the soul, the dreams and nightmares of symbolism imagined by Lalique, Fouquet or Carabin, as well as the forms and motifs borrowed from the Renaissance of Eug ne Grasset or Lucien Gaillard give way to a fauna and flora from a new biological, aquatic and underwater imagination, nourished by the popularization of great scientific discoveries and evolutionary thought. To better represent nature, Vever, Lalique, Boucheron, Fouquet and Nocq introduced new materials: horn, feather, a more diverse range of semi-precious stones. The study of plants as well as minerals and crystals, notably thanks to the magnificent plates created by the biologist Ernst Haeckel, also opened the way, from the 1900s, to a new decorative order revealing the crystalline structure of microorganisms. This restrained geometrization opens the field of abstraction and the Art Deco movement which will assert itself from the 1910s before triumphing in the 1920s. Accompanied by a glossary of materials and techniques and biographical notes of the main actors of period, this work allows us to understand the richness and stylistic evolution of jewelry and to place it in the art of its time.