Phlogopite
Chemical Formula	KMg3(AlSi3O10)(F,OH)2
Species	Silicates
Crystal System	Monoclinic
Mohs Scale	2-3
Specific Gravity	2.78-2.85
Color	Brownish red, dark brown, yellowish brown, green, white
Streak	White
Luster	Vitreous, Pearly
Refractive Index	n = 1.530 - 1.573 n = 1.557 - 1.617 n = 1.558 - 1.618
Diaphaneity	Transparent, Translucent
Cleavage	Perfecton
Fracture	Micaceous
Crystal Habit：Tabular, scaly masses, rarely perfect phenocryst tablets
Geological Setting：Contact and regional metamorphic limestones and dolomites, ultramafic rocks