Fourier transform Raman spectroscopy of kandite clays

Abstract

The Raman spectra of the kandite clay minerals, kaolinite, halloysite, dickite and nacrite, have been measured in the 180–3000 cm −1 region using Fourier transform near-IR Raman spectroscopy. These clays have a very small Raman cross-section and long data collection times were often required to obtain good spectra. Each clay has its own unique characteristic Raman spectrum which enables each kandite to be identified easily. In contrast, it is quite difficult to distinguish kandite clays by IR spectroscopy. Nacrite and dickite have relatively intense Raman peaks in the 1000–1100 cm −1 region, whereas kaolinite is characterized by an intense peak at 685 cm −1 and halloysite at 470 cm −1.