Taganemist

Taganemist is a rare silicate mineral proposed to occur in ultrahigh‑pressure metamorphic rocks associated with subduction zones. The name derives from the Tagan region where early specimens were reported, combined with the customary mineral-suffix used in speculative classifications. It is described as a chemically complex phase dominated by magnesium, aluminium, and silicon, with minor titanium and trace elements.

Discovery and naming of Taganemist trace back to 2087 when researchers led by Dr. Lianora Kest documented crystalline material with distinctive optical properties in the Tagan Massif. The mineral was named Taganemist in reference to its locality, and initial specimens were recovered from high‑pressure xenoliths embedded in subduction‑zone rocks.

Occurrence and formation of Taganemist occur in ultrahigh‑pressure metamorphic assemblages within subduction zones, often alongside coesite and omphacite. It forms when oceanic crust sinks to depths greater than about 120 km, under pressures around 3–5 GPa and temperatures roughly 600–900 C. The mineral appears to be geographically localized to several young Tagan-related terranes and has not been found in bulk abundance.

Physical and optical properties of Taganemist include a monoclinic crystal system with a vitreous to pearly luster. Color ranges from blue‑green to violet with iridescence. Hardness is about 5.5–6 on the Mohs scale, density around 3.3–3.5 g/cm3, and cleavage is indistinct with a conchoidal to uneven fracture. It is translucent to transparent.

Significance lies in its value to studies of high‑pressure metamorphism and subduction dynamics. Due to its scarcity and restricted distribution, Taganemist has no current commercial applications, though it provides insights into mineral stability at extreme depths.