Open AccessSpectral reflectance properties of zeolites and remote sensing implications
Author(s) -
Cloutis Edward A.,
Asher Pranoti M.,
Mertzman Stanley A.
Publication year - 2002
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000je001467
Subject(s) - aluminosilicate , spectral line , absorption spectroscopy , wavelength , absorption (acoustics) , absorption band , materials science , infrared spectroscopy , hydrogen bond , analytical chemistry (journal) , molecule , chemistry , mineralogy , optics , physics , biochemistry , optoelectronics , organic chemistry , chromatography , astronomy , composite material , catalysis
The 0.3‐ to 26‐μm reflectance spectra of a suite of 28 zeolites were measured and analyzed to derive spectral‐compositional‐structural relationships. Below ∼7 μm, the spectra are largely dominated by absorption features associated with zeolitic water. At longer wavelengths, the spectra are dominated by absorption features associated with the aluminosilicate framework. The spectra exhibit a number of systematic variations which can be used for both structural and compositional determinations. These include: (1) distinguishing different structural groups on the basis of wavelength position variations associated with absorption features in the 8.5‐ to 26‐μm region that are related to differences in the structure of the aluminosilicate framework; (2) determining the major cation which is present (Ca, Na, K) and the associated electronic environment of the zeolitic water on the basis of how these cations hydrogen bond to the water molecules in the void spaces and consequently affect water‐related absorption band positions, particularly in the 1.4, 1.9, and 2.0‐ to 2.5‐μm regions; (3) determining the Al:(Al + Si) ratio and SCFM chemical index on the basis of absorption features in the 7‐ to 26‐μm region which are most sensitive to these compositional variations; and (4) identifying iron‐bearing zeolites on the basis of absorption features in the 0.35‐ to 0.9‐μm region. The wavelength position and number of H 2 O‐associated absorption bands are sensitive to factors such as the type of major cation, degree of hydrogen bonding, and size of the void space, all of which are somewhat interrelated.