FeMgCaSiO4

FeMgCaSiO4 is a chemical formula representing a silicate composition that combines iron (Fe), magnesium (Mg), and calcium (Ca) with silicon and oxygen. It is not an established mineral species, but rather a hypothetical or endmember composition used in mineralogy and geochemistry to discuss multi-cation substitution within silicate lattices.

In a geological context, FeMgCaSiO4 can be thought of as a way to describe solid solutions where Fe, Mg, and Ca occupy cation sites in a silicate framework that contains SiO4 tetrahedra. Such a representation helps model how different cations substitute for one another in silicate minerals under varying pressure, temperature, and chemical conditions. While concrete mineral examples show specific stoichiometries (for instance, olivine (Mg,Fe)2SiO4 or pyroxenes such as CaMgSi2O6), FeMgCaSiO4 itself does not correspond to a single defined mineral phase.

Because it is not a documented mineral, FeMgCaSiO4 does not have a fixed set of physical properties (hardness, crystal system, refractive index, etc.). In practice, researchers would treat it as a notional endmember in petrographic modeling or thermodynamic simulations to explore how Fe, Mg, and Ca might distribute among lattice sites in mantle- or crustal silicates.

See also: olivine, forsterite, fayalite, diopside, hedenbergite, calcium-rich silicates, silicate solid solutions.