Biomineralization is an inherently structural subject; the structure of the mineral phase, the structure of the matrix composed of macromolecules and especially the structure of the interphase zone between them. Studies of the dynamics of mineral formation have revealed that a widespread strategy used by many organisms is to first form a disordered mineral phase. Only when it is in place and has adopted its appropriate shape, is it induced to crystallize. Matrix Studies have highlighted the importance Of a unique group of proteins that are rich in aspartic acid. These are involved in controlling mineral formation. Relating structure to function in mineralized tissues, often involves all understanding of mechanical properties in terms of not only the hierarchical structure Of the tissue, but also the graded structure that varies from one location to mother. Structure is thus in many respects the foundation upon which the field of biomineralization rests. (C) 2008 Elsevier Inc. All rights reserved.