Category Sulfate mineral Strunz classification 7.CB.35 Crystal system Monoclinic | Formula
(repeating unit) FeSO4·7H2O Dana classification 29.06.10.01 | |
 | ||
Crystal class Prismatic (2/m)
(same H-M symbol) | ||
Melanterite is a mineral form of hydrous iron(II) sulfate: FeSO4·7H2O. It is the iron analogue of the copper sulfate chalcanthite. It alters to siderotil by loss of water. It is a secondary sulfate mineral which forms from the oxidation of primary sulfide minerals such as pyrite and marcasite in the near-surface environment. It often occurs as a post mine encrustation on old underground mine surfaces. It also occurs in coal and lignite seams exposed to humid air and as a rare sublimate phase around volcanic fumaroles. Associated minerals include pisanite, chalcanthite, epsomite, pickeringite, halotrichite and other sulfate minerals.
It was first described in 1850.
References
Melanterite Wikipedia(Text) CC BY-SA