Pumpellyite-(Fe3+)
Pumpellyite is a group of closely related sorosilicate minerals: pumpellyite-(Mg): Ca2MgAl2[Si2O6OH][SiO4](OH)2(OH) pumpellyite-(Fe2+): Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH) pumpellyite-(Fe3+): Ca2Fe3+Al2[Si2O6OH][SiO4](OH)2O pumpellyite-(Mn2+): Ca2Mn2+Al2[Si2O6OH][SiO4](OH)2(OH) pumpellyite-(Al): Ca2AlAl2[Si2O6OH][SiO4](OH)2O Pumpellyite crystallizes in the monoclinic-prismatic crystal system. It typically occurs as blue-green to olive green fibrous to lamellar masses. It is translucent and glassy with a Mohs hardness of 5.5 and a specific gravity of 3.2.
Intro adapted from Wikipedia (CC BY-SA).
Pumpellyite-(Fe3+) is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₂Fe³⁺Al₂(Si₂O₇)(SiO₄)(OH,O)₂·H₂O.
It crystallizes in the monoclinic crystal system. It is a member of the Pumpellyite structural group.
Key properties: Mohs hardness 5; specific gravity 3.25; [Vitreous.] luster.
IMA symbol Pmp-Fe3+, IMA status: approved, named in 1972.
Found in altered porphyritic rocks.
It is found associated with Plagioclase, hematite.
The name refers to its membership in the pumpellyite group and dominant ferric iron content.