Antigorite
Chemical Formula	Mg，Fe3Si2O5OH4
Species	Silicates
Crystal System	Monoclinic
Mohs Scale	3-4
Specific Gravity	2.52
Color	green, green-blue, white, brown, black
Streak	greenish white
Luster	Vitreous
Refractive Index	n = 1.555 - 1.567 n = 1.560 - 1.573 n = 1.560 - 1.573
Diaphaneity	Transparent
Cleavage	Distinct/Good good
Fracture	Splintery