Tetrasilicate

Tetrasilicate is a term used in silicate chemistry to denote a structural motif containing four silicate tetrahedra (SiO4) linked through shared oxygen atoms. The four tetrahedra may connect in cyclic, linear, or branched arrangements, producing discrete oligomers or components of larger silicate networks.

One well-known example is the cyclotetrasilicate unit, [Si4O12]4-, a cyclic tetrasilicate anion formed by four SiO4 tetrahedra sharing oxygen corners. Such tetrasilicate species are discussed in the context of silicate speciation in solution, mineralogy, and materials science, and they illustrate how silicon-oxygen tetrahedra polymerize beyond the isolated orthosilicate unit.

In minerals and synthetic silicates, tetrasilicate units can serve as building blocks within more complex frameworks. However, tetrasilicate is not a formal mineral group name; it is a descriptive term for the four-tetrahedra unit and its arrangements, rather than a standalone mineral category.

Nomenclature in silicate chemistry reflects the degree of polymerization. Orthosilicate (nesosilicate) units consist of a single SiO4 tetrahedron, while higher-order units such as disilicate (Si2O7) and tetrasilicate (Si4O12) indicate increasing connectivity among tetrahedra. Tetrasilicate thus provides a convenient label for describing four-tetrahedra motifs encountered in both natural and synthetic silicate chemistry.