Literature about the natrolite and its Raman spectroscopy is as follow. , proposed a study of the vibrational spectra of natrolite. "Three principal optical methods can be used to measure the vibrational spectra of crystals: l) the absorption of infrared radiation, 2) the reflectance of infrared radiation, and 3) the Raman scattering of visible radiation. … Infrared absorption spectra in the far-infrared and infrared region are suitable especially for the determination of vibrations of water molecules, hydroxyl groups and local bonds in the structure of minerals. … The Raman and reflection spectra of polycrystalline natrolite have not been published yet [in 1983 and according to Pechar and Rykl' knowledge]" . "Bands of the antisymmetrical and symmetrical vibration of hydroxyl groups lie in the region 3300-3610 cm -1 . They have a very strong intensity in the IR spectra and a low intensity in the Raman spectra. The shift of this vibration relative to the wavenumber of the same vibration for water vapor indicates the presence of hydrogen bonds" (Pechar and Rykl, mentioning Hamilton and Ibers 1968).