The invention relates to a semi-synthetic powder material, derived from a natural marine biomaterial that is the inner aragonitic layer of the shell of bivalve molluscs chosen from the group comprising Pinctada, in particular Pinctada maxima and margaritifera, Tridacna, in particular Tridacna gigas, maxima, derasa, tevaroa, squamosa and crocea, Hippopus hippopus and Hippopus porcelanus, in powder form, supplemented with insoluble and soluble bio-polymers and calcium carbonate transformed by carbonation; it also relates to the method for preparing same and the uses thereof.