Mid-infrared bi-directional reflectance spectroscopy of impact melt glasses and tektites

For the application in remote sensing, spectral features have to be correlated with compositional characteristics of the materials. The dominating RB in the 7-14 µm range correlates well with the SiO2 content, the Christiansen Feature shows similar dependencies. To distinguish between glass and crystalline phases of the same chemical composition, a comparison between CF the SCFM index (SiO2/(SiO2 + CaO + FeO + MgO)) (Walter and Salisbury [1989] J. Geophys. Res., 94, 9203-9213) is useful, if chemical compositional data are also available.