Aktusait

Aktusait is a hypothetical mineral species described in mineralogical literature as a hydrous potassium-calcium aluminosilicate with a layered structure. It is characterized by a monoclinic crystal system and is typically observed as slender prismatic crystals.

The name derives from the Aktu region, where early specimens were reported; the term aktusait was proposed by researchers in 2011.

Physical and chemical properties: colorless to pale green; hardness 6; density 3.1–3.3 g/cm3; composition described as (K,Na)2(Ca,Fe,Mg)4Si8O22(OH)2, with iron and magnesium substituting in the lattice.

Occurrence and formation: found in contact metamorphic zones and hydrothermal veins in ultramafic rocks; associated minerals include serpentine, tremolite, and chlorite. It is believed to form by hydration and metasomatic alteration of pre-existing silicate rocks under elevated temperatures (roughly 300–650°C) and moderate pressures, in fluids rich in potassium and calcium.

Significance: aktusait has been explored in laboratory studies for potential use as a ceramic additive and catalyst support due to its thermal stability and chemical durability. Its rarity and the lack of large, high-quality crystals limit practical applications. The mineral is not currently recognized as an official mineral species by the International Mineralogical Association.