Zeolites are alumino-silicate minerals where usually water molecules are built into the crystal cructure. Zeolites are commonly forming as secondary minerals in volcanic rocks.
Zeolites (Greek, zein, "to boil"; lithos, "a stone") are hydrated aluminosilicate minerals and have a micro-porous structure.
The term was originally coined in the 18th century by a Swedish mineralogist named Axel Fredrik Cronstedt who observed, upon rapidly heating a natural mineral, that the stones began to dance about as the water evaporated. Using the Greek words which mean "stone that boil... -> See whole entry