Epsomite
Chemical Formula	MgSO4·7H2O
Species	Sulfates
Crystal System	Orthorhombic
Mohs Scale	2
Specific Gravity	1.67-1.68
Color	White, grey, colorless, or pink, greenish
Streak	White
Luster	Vitreous, Silky, Earthy
Refractive Index	n = 1.433 n = 1.455 n = 1.461
Diaphaneity	Transparent, Translucent
Cleavage	PerfectPerfect on , distinct on .
Fracture	Conchoidal
Crystal Habit：Acicular to fibrous encrustations
Geological Setting：Typically found growing as efflorescences in sheltered spots on outcrops of dolomitic or calcerous rocks; often found growing on the walls of caves and in salt lake deposits; also often found growing on the walls of coal and metal mines, including on wooden supports and abandoned equipment.