A pulverulent semisynthetic material, derived from a natural marine biomaterial, namely the aragonitic inner layer of the shell of bivalve molluscs selected from Pinctadines, notably Pinctada maxima, margaritifera, and Tridacnes, notably Tridacna gigas, maxima, derasa, tevaroa, squamosa, crocea, Hippopus hippopus, Hippopus porcelanus, in pulverulent form, with the addition of insoluble and soluble biopolymers and calcium carbonate transformed by carbonation.