Lawsonite
Chemical Formula	CaAl2Si2O7(OH)2·H2O
Species	Silicates
Crystal System	Orthorhombic
Mohs Scale	7
Specific Gravity	3.05-3.12
Color	Colorless, white, pale blue to grayish blue
Streak	White
Luster	Vitreous, Greasy
Refractive Index	n = 1.665 n = 1.672 - 1.676 n = 1.684 - 1.686
Diaphaneity	Transparent, Translucent
Cleavage	Perfect perfect poor
Fracture	Irregular/Uneven
Crystal Habit：Commonly prismatic, tabular; also granular, massive