The Near-Infrared Combination Band Frequencies of Dioctahedral Smectites, Micas, and Illites 论文

摘要

Abstract The highest frequency near-infrared (NIR) combination bands for specimens of four species of mica—montmorillonite-beidellite, illite, chlorite, and kaolinite—were correlated with respect to Al 2 O 3 content. A direct linear correlation was found between the combination band positions and the Al 2 O 3 contents of the montmorillonite-beidellite series, which may be given as: ν̄ cm −1 = (5.38 ± 0.04) (% Al 2 O 3 ) + (4412.8 ± 0.9). A similar linear correlation for muscovite is: ν̄ cm −1 = (6.10 ± 0.25) (% Al 2 O 3 ) + (4434.1 ± 8.3). Possible NIR band interferences are shown for different mineral mixtures, along with the correlation of different illites with muscovite. No combination bands were found in the frequency region 4425 cm −1 to 4625 cm −1 for specimens in which the Al 2 O 3 content was only in the tetrahedral layer sites.