Recent Research, lead by Prof. SE Wolf and Dr. J. Harris revealed that crystal lattice tilting, which hardens calcarous mollusk shells, can by generated in vitro by a pseudomorphic phase transformation of a thin, amorphous film of calcium carbonate generated at the air/water-interface. Under proper conditions, the quasi solid-to-solid transformation leads to intense crystal lattice tilting as featured by prismatic calcite in vivo. These results may pave the way for new biomimetic toughening mechanisms in vitro. The results were featured on the cover page of CrystEngComm.