Lazulite
Chemical Formula	(Mg,Fe2+)Al2(PO4)2(OH)2
Species	Phosphates
Crystal System	Monoclinic
Mohs Scale	5-6
Specific Gravity	3.122-3.240
Color	Azure-blue, sky-blue, bluish white, yellow-green, blue-green, rarely green
Streak	White
Luster	Vitreous
Refractive Index	n = 1.604 - 1.626 n = 1.626 - 1.654 n = 1.637 - 1.663
Diaphaneity	Transparent, Translucent
Cleavage	Poor/IndistinctPoor to good Indistinct on
Fracture	Irregular/Uneven, Splintery
Crystal Habit：Tabular, acute to stubby bipyramidal crystals; granular, massive
Geological Setting：In metamorphic rocks, border zones of complex granitic pegmatites, alluvial deposits.