Ferrocarpholite
The iron-dominant analogue of carpholite — a fibrous silicate of glaucophane-bearing metamorphic rocks.
Intro adapted from Wikipedia (CC BY-SA).
Ferrocarpholite is an IMA-recognized mineral species in the silicate class, with the chemical formula Fe²⁺Al₂Si₂O₆(OH)₄.
It crystallizes in the orthorhombic crystal system (space group Ccca). It is a member of the Carpholite structural group.
Key properties: Mohs hardness 5.5; specific gravity 3.04; optically biaxial.
IMA symbol Fcar, grandfathered status — known before the IMA’s founding, named in 1951.
Found in quartz veins in blueschists of low metamorphic grade, formed from felsic tuffs at about 250 ± C and 3 kbar.
It is found associated with Quartz, glaucophane, lawsonite, pumpellyite, jadeite, stilpnomelane.
The FERROus iron analogue of carpholite.