F388 (2017)

F388 (2017). Formation mechanism of CaCO3 spherulites in the myostracum layer of limpet shells.

CaCO3 spherulites were found in the myostracum layer of common limpet shells collected from East Sands, St Andrews, Scotland. Their microstructures were revealed by using powder XRD, SEM, HRTEM, and EDX. It was proposed that spherical particles of an inorganic and biological composite formed first. In the centre of each spherical particle a double-layer disk of vaterite crystal sandwiching a biological sheet developed. The disk crystal supplies a relatively strong mirror symmetric dipole field, guiding the orientations of the nanocrystallites and the arrangement of mesorods and, therefore, determining the final morphology of the spherulite. [S. T. Wu, C.-Y. Chiang, W. Z. Zhou, Crystals 7(10), 319 (2017)]