silicatecrystal

Silicatecrystal is a general term used to describe crystalline solids whose framework is built from silicate units, typically silicon-oxygen tetrahedra (SiO4) connected in a variety of ways. Although not a formal mineral name, the term is used in some syntheses and educational contexts to refer to any crystalline form whose major structural component is a silicate network. Silicatecrystals include naturally occurring minerals and synthetic crystals that display a silicate-dominated chemistry.

The structure of silicatecrystals is commonly categorized by how the SiO4 tetrahedra share oxygen atoms: nesosilicates with isolated tetrahedra, sorosilicates with paired tetrahedra, cyclosilicates with rings, inosilicates with single or double chains, phyllosilicates with sheet structures, and tectosilicates with three-dimensional frameworks. The crystal system and symmetry arise from the arrangement of these networks, giving rise to common mineral groups such as quartz (a tectosilicate) and feldspars (also tectosilicates). Crystals may belong to hexagonal, monoclinic, orthorhombic, tetragonal, trigonal, or cubic systems, among others.

Formation occurs by magmatic crystallization, metamorphic recrystallization, or hydrothermal processes. Properties vary widely but many silicatecrystals are hard, display distinct cleavage patterns, and show refractive indices that enable gemstone uses. Silicatecrystals are ubiquitous in the Earth’s crust and are also synthesized in laboratories for industrial applications, including silica materials for glass, ceramics, and silicon-based technologies. Examples range from clear quartz to layered micas and feldspars.