Linking gemology and spectral geology: a case study of elbaites from Seridó Pegmatite Province, Northeastern Brazil

Abstract reflectance spectroscopy is a fast tool for mineral identification and classification. We conducted spectral characterization of elbaite samples (n = 30) from Seridó Pegmatite Province, Borborema Province, NE Brazil, using a FieldSpec portable instrument and geochemical data from electron probe microanalysis. Visual interpretation of reflectance spectra reveals the absorption features in the visible to near infrared (350-1,200 nm) range related to the electronic transition processes of iron (e.g., ~720, ~1,180 nm), copper (e.g., ~694, ~922 nm) and manganese (e.g., ~400, ~520 nm) ions...