The structure actually contains open channels that allow water and large ions to travel into and out of the crystal structure. The size of these channels controls the size of the molecules or ions and therefore a zeolite like edingtonite can act as a chemical sieve, allowing some ions to pass through while blocking others. Edingtonite is one of only two zeolites to have barium in its chemistry. The heavy barium ion gives edingtonite the highest density of any zeolite. The larger amounts of water and the lower barium ion ratio lowers harmotome's density in relation to edingtonite.
Color is colorless or white.
Luster is vitreous to dull. Crystals can be transparent but most commonly are just translucent. Crystal System is tetragonal and orthorhombic. Crystal Habits include blocky to prismatic or bladed crystals usually with a square cross-section, also massive. Cleavage is perfect in one direction lengthwise.