temperatuuriandurite

Temperatuuriandurite is a hypothetical silicate mineral proposed in theoretical mineralogy to illustrate a temperature-dependent phase transition and associated optical changes. The name combines temperatuuri, Finnish for temperature, with the conventional mineral suffix -ite.

In proposed models, temperatuuriandurite has a layered silicate framework built from silicon-oxygen tetrahedra, with aluminum, iron, and/or magnesium in octahedral sheets. It exhibits a reversible high-temperature phase transition near 480–520°C, changing crystal symmetry from monoclinic to higher symmetry and accompanied by a noticeable change in optical properties. The transition may include a decrease in refractive index and a thermochromic color shift from pale to amber to reddish as the electronic structure reconfigures.

Physical properties assigned in speculative descriptions place temperatuuriandurite at Mohs hardness 5–6, density around 3.3–3.6 g/cm3, and moderate birefringence with weak pleochroism.

Occurrence and formation: Temperatuuriandurite is proposed to form during high-temperature metamorphism or hydrothermal alteration of aluminous silicates. In laboratory settings, synthetic samples are produced by solid-state reaction of precursor aluminous silicates at roughly 700–900°C under pressures of 1–2 GPa.

Analytical approach: Characterization relies on X-ray diffraction to observe the phase change, DSC to detect the endothermic transition near 500°C, and Raman spectroscopy to monitor Si–O vibrations. Electron microprobe analysis provides bulk composition.

Significance: If real, temperatuuriandurite could serve as a natural thermochromic sensor material or as a model system for temperature-induced phase transitions in silicates; current discussions are theoretical. See also thermochromism, phase-transition minerals, and durite analogs.