Ferrosaponite Locality: Levoberezhnoe Iceland spar deposit, Nizhnyaya Tunguska River Basin (Lower Tunguska River), Evenkia (Evenkiyskiy Autonomous okrug), Krasnoyarsk Territory (Krasnoyarsk Kray; Krasnoyarskii Krai), Eastern-Siberian Region, Russia Analysed specimen. Field of view 3 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Ferrosaponite
Ferrosaponite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₀.₃(Fe²⁺,Mg,Fe³⁺)₃(Si,Al)₄O₁₀(OH)₂·4H₂O.
It crystallizes in the monoclinic crystal system. It is a member of the Clay, Smectite-vermiculite structural group.
Key properties: Mohs hardness 2; specific gravity 2.49; Green streak; Vitreous luster; optically biaxial.
IMA symbol Fsap, IMA status: approved, named in 2002.
A hydrothermal mineral in association with pillow basalts.
It is found associated with Calcite, pyrite, quartz, mordenite, heulandite-Ca, stilbite-Ca.
Prefix, ferro, denotes the Fe2+-dominant analog of saponite.