Abstract: A jewel is formed from a plurality of components and comprises two mutually complementary elements, one of which forms a base and the other an insert. Both elements are incurved and at least one is not completely closed. The base has at least one window which crosses it from the concave side to the convex side and the insert has at least one protuberance complementary to the window of the base. Assembly of the two elements by penetration of the protuberance into the window of the base necessitates an elastic deformation of at least one of the two elements. At least one of the elements is interchangeable, which allows the appearance of the jewel to be changed.