Unusual Micrometric Calcite-Aragonite Interface in the Abalone Shell Haliotis~Mollusca, Gastropoda!

Yannicke Dauphin (1) , Jean-Pierre Cuif (1) , Hiram Castillo-Michel (2, 3) , Corinne Chevallard (4) , Bastien Farre (1, 5) , Anders Meibom (6)

1 IDES - Interactions et dynamique des environnements de surface
2 ID21
3 ESRF - European Synchrotron Radiation Facility
4 SIS2M UMR 3299 - Service Interdisciplinaire sur les Systèmes Moléculaires et les Matériaux (ex SCM)
5 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
6 EPFL - Ecole Polytechnique Fédérale de Lausanne

Species of Haliotis (abalone) show high variety in structure and mineralogy of the shell. One of the European species (Haliotis tuberculata) in particular has an unusual shell structure in which calcite and aragonite coexist at a microscale with small patches of aragonite embedded in larger calcitic zones. A detailed examination of the boundary between calcite and aragonite using analytical microscopies shows that the organic contents of calcite and aragonite differ. Moreover, changes in the chemical composition of the two minerals seem to be gradual and define a micrometric zone of transition between the two main layers. A similar transition zone has been observed between the layers in more classical and regularly structured mollusk shells. The imbrication of microscopic patches of aragonite within a calcitic zone suggests the occurrence of very fast physiological changes in these taxa.

Keywords: calcite; FTIR; biominerals; mollusk shells; aragonite; NanoSIMS

Domains: Invertebrate Zoology

Yannicke Dauphin, Jean-Pierre Cuif, Hiram Castillo-Michel, Corinne Chevallard, Bastien Farre, et al.. Unusual Micrometric Calcite-Aragonite Interface in the Abalone Shell Haliotis~Mollusca, Gastropoda!. Microscopy and Microanalysis, 2014, 20 (1), pp.276-284. ⟨10.1017/S1431927613013718⟩. ⟨insu-01056841⟩