Infrared reflection spectra (2500-250 cm-1) of some minerals and rocks were recorded with a multiplescan interference spectrometer. Samples were small, irregular, and unpolished. Spectra were obtained with some samples approximately 1 mm in diameter. Emission of samples was obviated by using the interferometer as chopper.
M. J. D. Low, "Measurement of the Infrared Spectral Reflection of Some Common Minerals and Rocks Using Multiple-Scan Interferometry," Appl. Opt. 6, 1503-1506 (1967)