To See the World in a Grain of Sand: Recognizing the Origin of Sand Specimens by Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Multivariate Exploratory Data Analysis

The diffuse reflectance infrared Fourier transform (DRIFT) spectra of sand samples exhibit features reflecting their composition. Basic multivariate analysis (MVA) can be used to effectively sort subsets of homogeneous specimens collected from nearby locations, as well as pointing out similarities in composition among sands of different origins. This experiment is designed for graduate students and provides a practical application of both solid-state spectroscopy and chemometrics. It is helpful to students acquainted with MVA and willing to develop some spectroscopic skills. Conversely, the technique can be used by students familiar with spectroscopy who wish to investigate multivariate exploratory data analysis. The spectra can also illustrate a discussion of the spectroscopy of minerals (ad-hoc flowcharts for the identification of the main constituents of sands through their spectral features are proposed).