Hydrous framework aluminosilicates which have large channels. They are built of frameworks of AlO₄ and SIO₄ tetrahedra. They are of technological importance because the channels allow zeolites to absorb a wide variety of substances, making them useful in sewage treatment, as a dessicant, to separate gases in natural gas, in kitty litter, and is being tested for remediation. Some zeolites are also used in chicken and pig feed, as they (for some reason) make the animals healthier and larger.

Zeolites are low temperature minerals which form in the alkaline brine of playa lakes. The combination of H₂O, clays, and high concentrations of salts, including Na₂SO₄ [thenardite] and MgNa₂(SO₄)₂H₂O [blödite] allow the formation to occur.

Name	Formula	Crystal System
Analcime	NaAlSi2OH2O	Cubic
Brewsterite	(Sr,Ba,Ca)Al2Si605H2O	Monoclinic
Chabazite	(Ca,Na2)Al2Si406H2O	Hexagonal
Clinoptilolite	(Na,K)4CaAl6Si30O24H2O	Monoclinic
Dachiardite	(K2,Na2,Ca)Al5Si19O18H2O	Monoclinic
Edingtonite	BaAl2Si3O104H2O	Tetragonal
Epistilbite	CaAl2Si6O5H2O	Monoclinic
Erionite	(Na2,K2,Ca)Al9Si27O27H2O	Hexagonal
Faujasite	(Na2,Ca)AlSiO16H2O	Cubic
Ferrierite	(Na,K)4Mg2Al6si30O72(OH)218H2O	Orthorhombic
Gismondine	CaAl2Si2O84H2O	Monoclinic
Gmelinite	(Na2,Ca)Al2Si4O6H2O	Hexagonal
Gonnardite	Na2CaAl4Si6O205H2O	Orthorhombic
Harmotome	BaAl2Si6O166H2O	Monoclinic
Heulandite	(Ca,Na2)4Al8Si28O24H2O	Monoclinic
Laumontite	CaAl2Si4O4H2O	Monoclinic
Levyne	CaAl2Si4O126H2O	Hexagonal
Mesolite	Na2Ca2Al6Si9O8H2O	Orthorhombic
Mordenite	(Na2,K2,Ca)Al2Si10O247H2O	Orthorhombic
Natrolite	Na4Al4Si6O4H2O	Orthorhombic
Phillipsite	(K2,Na2,Ca)32Al6Si10O12H2O	Monoclinic
Scolecite	Ca2Al4Si6O6H2O	Monoclinic
Stilbite	(Ca,Na2,K2)4Al8Si28O28H2O	Monoclinic
Thomsonite	NaCa2Al5Si5O6H2O	Orthorhombic
Wairakite	CaAl2Si4O2H2O	Monoclinic
Yugawaralite	CaAl2Si6O4H2O	Monoclinic