Furthermore, the chemical environment of the phosphate elucidated in ss-NMR (Akiva-Tal et al., 2011) indicates that it is well dispersed inside the ACC structure. These observations, however, do not rule out that a combination of several factors (proteins, inorganic phosphate, small organic molecules) could act cooperatively to enhance the stability of gastrolithic ACC. Additionally, taking into account the prospected layer-by-layer deposition, local differences in structure and composition, as indicated in previous work (Akiva-Tal et al., 2011; Bentov et al., 2010) could provide vital clues for the stabilization mechanism of ACC