Color is usually colorless and pale gray to white. Diaphaneity is transparent to translucent. Cleavage is perfect in one direction.
Fracture is uneven.
Hardness is 5. Streak is white. Associated Minerals include aegirine, ancylite, apophyllite series, calcite, catapleiite, monteregianite, nenadkevichite, pectolite, tadzhikite and vesuvianite.