TY - JOUR T1 - Amorphous-to-crystal transition in the layer-by-layer growth of bivalve shell prisms A1 - Duboisset,Julien A1 - Ferrand,Patrick A1 - Baroni,Arthur A1 - Grünewald,Tilman A. A1 - Dicko,Hamadou A1 - Grauby,Olivier A1 - Vidal-Dupiol,Jeremie A1 - Saulnier,Denis A1 - Le Moullac,Gilles A1 - Rosenthal,Martin A1 - Burghammer,Manfred A1 - Nouet,Julius A1 - Chevallard,Corinne A1 - Baronnet,Alain A1 - Chamard,Virginie AD - Aix-Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France AD - Aix-Marseille Univ, CNRS, CINaM, Campus Luminy, Case 913, 13288-Marseille cedex 9, France AD - IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier France AD - Ifremer, UMR 241 Environnement Insulaire Océanien (EIO), Labex Corail, Centre du Pacifique, BP 49, Vairao 98719, French Polynesia AD - European Synchrotron Radiation Facility, F-38043 Grenoble Cedex, France AD - GEOPS, Univ. Paris-Sud, CNRS, Université Paris-Saclay, 91405 Orsay, France AD - NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex, France UR - https://archimer.ifremer.fr/doc/00747/85863/ DO - 10.1016/j.actbio.2022.01.024 KW - Biomineralization KW - Mollusk prisms KW - Pinctada margaritifera KW - Pinna nobilis KW - Coherent raman microscopy KW - Vectorial ptychography N2 - Biomineralization integrates complex physical and chemical processes bio-controlled by the living organisms through ionic concentration regulation and organic molecules production. It allows tuning the structural, optical and mechanical properties of hard tissues during ambient-condition crystallisation, motivating a deeper understanding of the underlying processes. By combining state-of-the-art optical and X-ray microscopy methods, we investigated early-mineralized calcareous units from two bivalve species, Pinctada margaritifera and Pinna nobilis, revealing chemical and crystallographic structural insights. In these calcite units, we observed ring-like structural features correlated with a lack of calcite and an increase of amorphous calcium carbonate and proteins contents. The rings also correspond to a larger crystalline disorder and a larger strain level. Based on these observations, we propose a temporal biomineralization cycle, initiated by the production of an amorphous precursor layer, which further crystallizes with a transition front progressing radially from the unit center, while the organics are expelled towards the prism edge. Simultaneously, along the shell thickness, the growth occurs following a layer-by-layer mode. These findings open biomimetic perspectives for the design of refined crystalline materials. Statement of Significance Calcareous biominerals are among the most present forms of biominerals. They exhibit astonishing structural, optical and mechanical properties while being formed at ambient synthesis conditions from ubiquitous ions, motivating the deep understanding of biomineralization. Here, we unveil the first formation steps involved in the biomineralization cycle of prismatic units of two bivalve species by applying a new multi-modal non-destructive characterization approach, sensitive to chemical and crystalline properties. The observations of structural features in mineralized units of different ages allowed the derivation of a temporal sequence for prism biomineralization, involving an amorphous precursor, a radial crystallisation front and a layer-by-layer sequence. Beyond these chemical and physical findings, the herein introduced multi-modal approach is highly relevant to other biominerals and bio-inspired studies. Y1 - 2022/04 PB - Elsevier BV JF - Acta Biomaterialia SN - 1742-7061 VL - 142 SP - 194 EP - 207 ID - 85863 ER -