Mussel's calcitic shell growth adheres to physical laws familiar from processes used to optimise steel
Mussels are veritable masters of biomineralisation. They make hard, robust composite materials from simple substances in order to build their shells. Furthermore, the shell material itself is produced in an exemplary way. A Franco-German team working with scientists at the Max Planck Institute of Colloids and Interfaces in Potsdam studied the giant Mediterranean fan mussel Pinna nobilis and was able to acquire a better understanding of crystallite growth. The scientists found that the calcite crystallites in the outer prismatic layer develop in a very similar manner to that of crystallites observed in metals, and in line with materials theories. Accordingly, a number of large crystallites continue to grow, displacing smaller grains, which gradually shrink. The results show clearly that the mussel, a living organism, employs processes that are similar to those used to optimise steels. This means that besides providing the thermodynamic conditions for calcite grain growth, such as temperature...