MSiO4

MSiO4 is a general chemical formula used to describe a family of inorganic compounds consisting of a metal cation M and a silicate unit SiO4 in a 1:1:4 ratio. In these compounds, the SiO4 tetrahedra link together to form a three-dimensional silicate framework, with the M4+ cations occupying interstitial sites to balance charge. The identity of M determines the mineralogical or synthetic phase, and the structure commonly adopts motifs associated with tetravalent cations.

Natural examples include zircon (ZrSiO4) and hafnon (HfSiO4), which crystallize in the tetragonal zircon structure. Thorite (ThSiO4) is another well-known mineral with this composition. Many other MSiO4 end-members are possible when M is a tetravalent cation such as Zr4+, Hf4+, Th4+, or Ce4+, and solid solutions between different M cations occur in both natural samples and synthetic materials. The zircon-type structure is the most common framework for these silicates, though variations can occur under differing pressure and temperature conditions.

Occurrence and applications: MSiO4 minerals occur in various igneous and metamorphic rocks, often as accessory phases. In materials science, MSiO4-structured silicates are studied for their chemical stability and high-temperature behavior, with interest in ceramics and optical applications where refractory and durable silicates are advantageous. The exact properties depend on the choice of the metal M and any substitutions within the solid solution.

See also: zircon, hafnon, thorite, silicate minerals.