“…In nature, silica can be found in solid, liquid or absorptive state, in particular in silicon dioxide (SiO2), silica (SiO2 • nH2O), and oligo-and poly silicon acids (H2SiO3, H4SiO4). Si is part of clay minerals and silicates, while pure silicon is found as quartz, opal and other structures (Kovda, 1973;Matychenkov, 2008). Most of the reviews are devoted to the role of silicon in the life of freshwater and marine macro-and microalgae, including the formation of complex skeletal structures, such as the diatom frustule, intricate skeletons and scales covering chrysophytes.…”