Clays and Clay Minerals, Vol. 56, No. 4, 470–485, 2008.
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Authors
Johnston, Cliff T.
Kogel, Jessica Elzea
Bish, David L.
Kogure, Toshihiro
Murray, Haydn H.
Issue Date
2008
Type
Article
Language
Keywords
Periodicals , Geology , Dickite , FTIR Spectroscopy , Hinckley Index , Kaolin-group Minerals , Kaolinite , Low temperature FTIR Spectroscopy , Nacrite , Structural Disorder
Alternative Title
Low-temperature Ftir Study Of Kaolin-group Minerals
Abstract
Low-temperature FTIR spectroscopy was used to characterize the n(OH) region of kaolingroup minerals including well ordered to poorly ordered kaolins from Georgia, Brazil, and England, along with samples of discrete dickite and nacrite. Low-temperature FTIR spectra were useful in resolving dickite- and nacrite-like features present in the spectra of kaolins when cooled to <30 K. These features were not resolved at room temperature and only partially resolved at liquid N2 temperature (77 K). The room-temperature and low-temperature positions of the n(OH) bands of kaolinite, dickite, and nacrite were linearly correlated with the interatomic OH_O distances and this relationship served as the basis for polytype/disorder identification. Dickite or dickite-like disorder was found in high Hinckley-Index kaolinite from Keokuk, Iowa, and from Cornwall, England. Dickite- and nacrite-like features were observed in both high- and low-Hinckley-index kaolinite and the amounts of these stacking sequences generally increased with decreasing Hinckley Index.
Description
gsccm56408-joh.pdf 571KB
Citation
Clays and Clay Minerals, Vol. 56, No. 4, 470–485, 2008.
Publisher
The Clay Minerals Society
License
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