Tags: Chemical Substance, Mineral.
Piemontite is a sorosilicate mineral in the monoclinic crystal system with the chemical formula Ca2(AlMn3+Fe3+)3(SiO4)(Si2O7)O(OH). It is a member of the epidote group.Red to reddish-brown or red-black in colour Piemontite has a red streak and a vitreous lustre.The type locality is the Prabornaz Mine in Saint-Marcel Aosta Valley Italy.It occurs metamorphic rocks of the greenschist to amphibolite metamorphic facies and in low-temperature hydrothermal veins in altered volcanic rocks.
