title: Visible and near-infrared spectroscopic comparison of five phyllosilicate mineral samples.
abstract: Portable visible and near-infrared (vis/NIR) spectroscopy was used to characterize and differentiate the five phyllosilicate minerals and relate the bands to the mineral structure. The feature band at 2160-2170nm (4600-4630cm-1) has been assigned to the high presence of Al-OH and is described as typical of dioctahedral phyllosilicate with OH groups coordinated around Al, and the feature occurred near 2322nm is considered to be due to a combination of the OH stretch with the MgOH deformation mode, which is a typical of trioctahedral phyllosilicates. The presence of the bands 1400 and 1900nm in vis/NIR spectrum indicated that some water is present in this sample. The absence of a 1900nm band but the presence of a 1400nm band indicates that only OH is present. Moreover, the significant differences between these five minerals were observed by the portable vis/NIR spectroscopy. The results show a potential for the application of vis/NIR spectroscopy in the identification and quantification of these minerals in the field. Further, such analysis can also provide important constraints on the nature of putative global and local-scale mineralogical transitions on Mars.
authors.affiliation: School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083, PR China; State Key Laboratory of Coal Resources and Safe Mining, China University of Mining & Technology, Beijing 100083, PR China. Electronic address: h.cheng@cumtb.edu.cn.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Cheng
authors.affiliation: School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083, PR China.
authors.forename: Riwa
authors.initials: R
authors.lastname: Hao
authors.affiliation: School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001, Australia. Electronic address: r.frost@qut.edu.au.
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
keywords: Kaolinite; Phyllosilicate minerals; Portable; Pyrophyllite; Visible and near-infrared spectroscopy