Charoite

Charoite (K(Ca,Na)₂Si₄O₁₀(OH,F)·H₂O) is a rare silicate mineral, first described in 1978 and named for the Chara River. It has been reported only from the Sakha Republic, Yakutia, Siberia, Russia. It is found where a syenite of the Murunskii Massif has intruded into and altered limestone deposits producing a potassium feldspar metasomatite.