The influence of minor environmental factors

such as the geomagnetic field

on the biomineralization of nacres

is often ignored but a great deal of research has confirmed its important role in the normal mineralization of calcium carbonate. Although the geomagnetic field is weak

its cumulative effects need to be considered given that the biomineralization process can take years. Accordingly

the authors of this paper have investigated the effects of weak magnetic fields (25 Gs or 50 Gs) on calcium carbonate mineralization and analyzed the mechanism involved. The results show that even a weak magnetic field conduces to the formation of vaterite or aragonite

in the induction order of precursor → vaterite → aragonite. The stronger the magnetic field and the longer the time

the more obvious the induction effect. The effect of a magnetic field is strongest in the aging stage and weakest in the solution stage. Inductions by egg-white protein and by a magnetic field inhibit each other

but they both restrict particle growth. These findings highlight the importance of minor environmental factors for biomineralization and can serve as a reference for biomimetic preparation of a CaCO

3

nacre-like structure and for anti-scale technolog

y for circulating cooling water.