Color is white or colorless. Also green or brown. Luster is vitreous to dull. Transparency crystals are transparent to translucent. Nodules or concretions are lamellar to fiberous.
Cleavage is perfect in one direction.
Fracture is uneven. Hardness is 3 - 4. Streak is white. Associated Minerals are okenite , apophyllite , quartz , laumontite and other zeolites. Best Field Indicators are crystal habit, luster and associations.