Sylvite
Chemical Formula	KCl
Species	Halides
Crystal System	Isometric
Mohs Scale	1-2
Specific Gravity	1.987
Color	Colorless to white, pale gray, pale blue; may be yellowish redto red due to hematite inclusions
Streak	white
Luster	Vitreous
Refractive Index	n = 1.4903
Diaphaneity	Transparent, Translucent
Cleavage	PerfectOn
Fracture	Irregular/Uneven
Crystal Habit：As cubes and octahedra; columnar, in crusts, coarse granular, massive
Geological Setting：Evaporites in sedimentary basins, sublimate in volcanic fumaroles, burning coal.