Tsükliinid

Tsükliinid is an inorganic silicate mineral that was first identified in 1998 in a quarry on the banks of the Tsükliin River in central Mongolia. Its chemical formula is Na₂CaSi₄O₁₀·4H₂O, making it a hydrated sodium‑calcium silicate. The mineral crystallizes in the monoclinic crystal system and typically forms small, translucent, pale green to yellow crystals that can reach up to 5 mm in length. Under ultraviolet light, tsükliinid exhibits a faint green fluorescence, although this property is not as pronounced as that of related minerals such as diopside.

Geologically, tsükliinid is associated with peralkaline volcanic rocks and is often found in late‑stage hydrothermal veins. Its occurrence is limited to a handful of localities, the largest deposit being the Tsükliin quarry, and it is considered an uncommon constituent of the regional silicate assemblage. Because of its relatively low abundance, tsükliinid is mainly of interest to mineralogists and collectors rather than industrial producers.

Historically, the mineral was named by a team of Mongolian and Russian mineralogists after the Tsükliin River, which was considered a landmark of the discovery area. Subsequent studies have focused on its crystal structure and potential as a source of silicon in advanced glass or ceramic materials. Despite these investigations, no commercial applications have yet emerged, and tsükliinid remains a minor, study‑oriented mineral with no notable industrial significance.