Gismondine
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]. It has been found in Iceland, Ireland, and Italy.