External reflectance FTIR dataset (4000–400 cm−1) for the identification of relevant mineralogical phases forming Cultural Heritage materials

The use of vibrational spectroscopy is gaining more and more relevance in the field of the identification and characterization of Cultural Heritage materials. In this frame we propose and discuss a copious collection of Fourier Transform Infrared (FTIR) spectra acquired in external reflectance (ER) mode (4000–400 cm−1), which is a non-destructive and inexpensive analytical technique. Up to 192 spectra were collected, processed and made free-available to the scientists and professionals working in the Cultural Heritage sector. Color and inclusions, optical anisotropy, polymorphism and isomorphism, water content, crystallinity index, polyphasicity are some properties that have driven to rationale of the paper for discriminating groups of geomaterials usually found in studies aimed at the valorization and conservation of Cultural Heritage. Finally, this study offers a robust opportunity to beginners who intend to use ERFTIR as a tool in the field of qualitative and non-destructive mineralogical analysis.