What is "natrolite"

Natrolite \Na"tro*lite\ (?; 277), n. [Natron + -lite: cf. F. natrolithe.] (Min.) A zeolite occuring in groups of glassy acicular crystals, and in masses which often have a radiated structure. It is a hydrous silicate of alumina and soda.

n. (context mineralogy English) A fibrous zeolite mineral, being a sodium aluminosilicate, of the chemical formula sodium₂aluminum₂silicon₃oxygen₁₀'''·'''2water.

n. a group of minerals of the zeolite family consisting of a hydrous silicate of sodium and aluminum

Natrolite is a tectosilicate mineral species belonging to the zeolite group. It is a hydrated sodium and aluminium silicate with the formula . The type locality is Hohentwiel, Hegau, Germany.

It was named natrolite by Martin Heinrich Klaproth in 1803. The name is derived from νατρών natron, the Greek word for soda, in reference to the sodium content and λίθος lithos, meaning stone. Needle stone or needle-zeolite are other informal names, alluding to the common acicular habit of the crystals, which are often very slender and are aggregated in divergent tufts. The crystals are frequently epitaxial overgrowths of natrolite, mesolite, and gonnardite in various orders.