FeSitype
FeSitype is a term used in mineralogy and materials science to denote a family of iron sulfide phases that share common Fe–S bonding motifs and display variable stoichiometry. The name combines the chemical symbols Fe and S with the suffix -itype to indicate a type of iron sulfide that extends beyond the well-known endmembers troilite (FeS) and pyrrhotite (Fe1−xS). In this framework, a FeSitype phase refers to defect-ordered or compositionally distinct sulfide structures that arise from variations in iron occupancy and sulfur content.
Crystal chemistry and structure: FeSitype phases may exhibit hexagonal, monoclinic, or other lattice symmetries depending on
Occurrence and formation: In natural settings, iron-sulfide assemblages form during high-temperature magmatic differentiation, hydrothermal activity, or
Properties and applications: FeSitype materials typically exhibit metallic conductivity with magnetic responses that reflect the behavior
See also: iron sulfide, troilite, pyrrhotite, pyrite, sulfide minerals.