Gismondine is a mineral with the chemical formula CaAl2Si2O8·4H2O. It is a zeolite or hydrated aluminosilicate. It forms colorless, bipyramidal crystals of orthorhombic symmetry.
Gismondine was named for Italian mineralogist Carlo Giuseppe Gismondi (1762–1824). It has been found in Iceland, Ireland, and Italy.
References Encyclopædia Britannica online entry Gismondine data at webmineral.com
External links Structure type GIS