Interpretation of the Reflectance Spectra of Lithium (Li) Minerals and Pegmatites: A Case Study for Mineralogical and Lithological Identification in the Fregeneda-Almendra Area

Reflectance spectroscopy has been used to identify several deposit types. However, applications concerning lithium (Li)-pegmatites are still scarce. spectroscopic studies complemented by microscopic and geochemical were employed in the Fregeneda–Almendra (Spain–Portugal) pegmatite field analyze spectral behavior of Li-minerals lithologies. The similarity target class (Li-pegmatites) with other elements was also evaluated. Lepidolite discriminated from white micas remaining Li-minerals. No diagnostic feature petalite spodumene identified, since their curves dominated clays. Their presence corroborated (by complementary techniques) relics completely replaced crystals, although clay-related absorption depths decrease Li content. This implies that clays can be as pathfinders only areas where argillic alteration is not prevalent. All sampled lithologies present similar water and/or hydroxide features. overall mineral assemblage very distinct, lepidolite, cookeite, orthoclase exclusively identified Li-pegmatite (being these minerals crucial targets for discrimination real-life applications), while chlorite biotite occur Satellite data discriminate Li-pegmatites due distinct reflectance magnitude assemblages, higher absorptions depths, Al–OH wavelength position. potential use multi- hyperspectral evaluated; main limitations advantages discussed. These new insights on pegmatites may aid discoveries around world.