biomineralisation

Biomineralisation, also spelled biomineralization in American English, is the process by which living organisms produce inorganic minerals often within organic matrices to form complex, functional structures. The resulting materials—such as bones, teeth, shells, and skeletons—provide mechanical support, protection, buoyancy, or defense while often displaying intricate nanostructures and hierarchical organization. The minerals are typically calcium carbonate, calcium phosphate, silica, or magnetic minerals, synthesized in controlled cellular or extracellular environments.

Organisms employ two broad strategies: biologically controlled and biologically induced mineralisation. In controlled biomineralisation, cells orchestrate mineral deposition by regulating ion transport, pH, and the expression of specific proteins and matrix vesicles that template or nucleate crystals. In induced biomineralisation, metabolic activities create favorable conditions for minerals to precipitate on existing templates or matrices without direct genetic control. The resulting minerals can exist in different polymorphs and microstructures.

Notable examples include molluscan shells composed of calcium carbonate with nacreous layers; marine invertebrate skeletons of calcite or aragonite; vertebrate bones and teeth where hydroxyapatite crystals reinforce collagen; and enamel, dentin and cementum. Silica-based structures in certain sponges and diatoms, and magnetic iron-oxide particles in magnetotactic bacteria, also illustrate biomineralisation. The forms are often highly organized and nanoscale features influence macroscopic properties.

Biomineralisation has ecological and evolutionary significance, contributing to fossil records and material diversity. It also inspires biomimetics and materials science, guiding the design of composites, sensors, and sustainable production methods. Spelling varies by region (biomineralisation vs biomineralization).