Confined crystallization of polycrystalline high-magnesium calcite from compact Mg-ACC precursor tablets and its biological implications

A simple route for incorporation of Mg in the formation of polycrystalline high-magnesium calcite through Mg-ACC crystallization in the absence of any organic additives by use of a so-called squash technique method has been reported. By this method, we first point out that the confined crystallization plays a key role in preventing the escape of Mg2+ and incorporation of magnesium in calcite lattice, which may suggest that the confined environment could also play a role in the formation of biological magnesium calcite. For example, the confinement by means of organic matrices in biomineralization is frequently observed. Moreover, the confined crystallization can give help in capturing some intermediate states.