Melanterite
Chemical Formula	FeSO4·7H2O
Species	Sulfates
Crystal System	Monoclinic
Mohs Scale	2
Specific Gravity	1.89-1.9
Color	Green, pale green, greenish blue, bluish green, colorless
Streak	White
Luster	Vitreous
Refractive Index	n = 1.470 - 1.471 n = 1.477 - 1.480 n = 1.486
Diaphaneity	Translucent, Opaque
Cleavage	PerfectPerfect on , distinct on .
Fracture	Conchoidal
Crystal Habit：Encrustations and capillary efflorescences; rarely as equant pseudo-octahedral, prismatic or tabular crystals
Geological Setting：A secondary mineral formed by the oxidation of iron sulfide minerals, such as pyrite and marcasite, it is found occurring naturally in sheltered crevices and cavities in sulfidic sedimentary and metamorphic rocks, and in coal and lignite deposits. It also forms readily on the walls, timbers, and other structures in mines.