Color is usually colorless or white to grayish. Luster is vitreous to adamantine. Diaphaneity is transparent to translucent. Crystal Habits include short tetragonal prisms and radiating spherical aggregates.
Fracture is splintery to uneven.
Hardness is 4 - 5. Streak is white. Associated Minerals include analcime, chlorite group, fluorite, microcline, rutile, siderite and zircon.