Modern Views on Desilicification: Biosilica and Abiotic Silica Dissolution in Natural and Artificial Environments

A review relating to modern views on biosilica and abiotic silica as well as with the basic information on principles of desilicification was reported. Biogenic silica exhibits diversity in structure, density, and composition and can exist in several structural forms, including sheet-like, globular, fibrillar, helical, tubular, and folded sheets. The mechanism of silica dissolution from mineralized organisms is well described by models used for inorganic minerals in aqueous media taking into consideration surface speciation. These models explain satisfactorily not only the kinetics of dissolution but also the importance of functional groups involved in most types of the organic matrix. Bacteria and fungi, worms, and in general cells and tissues have a catalytic effect on dissolution of various forms of silica both amorphous and crystalline. Silica/silicate deposits can be desilicified or dissolved by the action of a variety of silicon-chelating molecules.