A term now used to designate any one of a family of minerals, hydrous silicates of alumina, with lime, soda, potash, or rarely baryta. Here are included natrolite, stilbite, analcime, chabazite, thomsonite, heulandite, and others. These species occur of secondary origin in the cavities of amygdaloid, basalt, and lava, also, less frequently, in granite and gneiss. So called because many of these species intumesce before the blowpipe.
(1) (Geology) Any of various hydrous silicates that are analogous in composition to the feldspars, occur as secondary minerals in cavities of lavas, and can act as an ion-exchanger. (2) (Chemistry) Also, any of various natural or synthesized silicates of similar structure used especially in water softening and as an adsorbent and catalyst. (3) (Water Quality) A type of ion exchange material used to soften water. Natural zeolites are siliceous compounds which remove calcium and magnesium from hard water and replace them with sodium. Synthetic or organic zeolites are ion exchange materials which remove calcium or magnesium and replace them with either sodium or hydrogen.
A group of hydrated sodium aluminosilicates, either natural or synthetic, with ion exchange properties.
Family of hydrated silicates which occur as porous mineral crystals; used for their absorptive properties, as catalysts, separating agents, sequestrants in washing powders, etc.
A generic term for a group of hydrous alumino-silicate minerals that occurs in cracks and cavities of igneous rocks, especially the more basic lavas.
mineral used to adsorb ammonia, can be re-used after soaking in salt.
Addition compounds of the type Na2O·Al2O3·n SiO2·m H2O, with calcium sometimes replacing or present with the sodium. The sodium in the zeolite exchanges with calcium in water, making zeolites useful for water softening. The porous structure of zeolites also makes them effective molecular sieves used as gas adsorbents and drying agents. Artificial zeolites are used as ion exchange resins.
Zeolite is a natural or synthetic hydrated aluminosilicate with an open three-dimensional crystal structure, in which water molecules are held in cavites in the latice. The water can be driven off by heating and the zeolite can then absorb other molecules of suitable size. Zeolites are used for separating mixtures by selective absorption.
any of a family of glassy minerals analogous to feldspar containing hydrated aluminum silicates of calcium or sodium or potassium; formed in cavities in lava flows and in plutonic rocks
A naturally occurring ore which will chelate (remove) ammonia and soften water. It is only effective in fresh water.
An absorbent material (in the form of small pellets) used in low-temperature cryostats to trap gases released gradually after active pumping has ceased. See outgassing. [McL97
A group of hydrous silicates of aluminum, containing sodium and calcium, and giving off water upon heating; technically, a substance capable of absorbing large quantities of carbon dioxide.
Crystalline hydrated silicates from volcanoes. Molecular cages trap and remove heavy metal pollutants, makeup and dirt. Crystalline hydrated silicates 'trap' heavy metal pollutants.
A group of hydrous aluminosilicates that are similar to the feldspars. They easily lose and regain their water of hydration and they fuse and swell when heated. Zeolites are frequently used in water softening, ion exchange and absorbent applications
Zeolites (Greek, zein, "to boil"; lithos, "a stone") are minerals that 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 boils," he called this material zeolite.
