MgSO 4 - 7H 2 O . MgSO 4 - 6H 2 O . Kieserite lends its name to a group of sulfates called the Kieserite Group . Color is white, colorless, gray or yellowish. Luster is vitreous.
Crystals are translucent.
Crystal Habits include granular masses. Individual crystals are rare. Cleavage is perfect in one direction. Fracture is uneven. Streak is white.