Spinelrelated

Spinelrelated is an adjective used in mineralogy and materials science to describe minerals, phases, and compounds that are related to or derived from the spinel family of oxide minerals. The term commonly applies to substances that share the characteristic spinel crystal structure, which has the general formula AB2O4 and a cubic close-packed oxygen lattice with A cations occupying tetrahedral sites and B cations occupying octahedral sites. Spinelrelated materials may be ordinary spinels, inverse spinels, or solid solutions where cations distribute differently among the available lattice sites.

Within the spinel framework, normal spinels have divalent A cations in tetrahedral sites and trivalent B cations in octahedral sites, while inverse spinels exhibit a rearrangement with B cations occupying tetrahedral sites and a mixture of A and B cations in octahedral sites. This structural flexibility underpins a wide range of compositions, including magnesium aluminum spinel (MgAl2O4), chromite (FeCr2O4), magnetite (Fe3O4), and related minerals such as hercynite (FeAl2O4) and galaxite (MnAl2O4).

Occurrences and significance vary: spinelrelated minerals are common in ultramafic and metamorphic rocks and often appear as inclusions in mantle-derived rocks, contributing to geothermobarometry and petrogenetic interpretations. In gemstones, natural spinels are valued for color and clarity, while synthetic spinels are used in optics and armor ceramics. The term also applies to materials engineers studying spinel-structured ceramics and mixed-oxide systems, where spinel-related phases influence high-temperature stability and ionic conduction.

See also: spinel, spinel group minerals, inverse spinel, solid solution series, spinel ceramics.