This book systematically provides an overview of the use of a wide range of spectroscopic methods (Mid- and Near-Infrared, Infrared Emission, Raman, Solid-State Magic Angle Spinning Nuclear Magnetic Resonance, X-ray Photoelectron, Extended X-ray Absorption Fine Structure, X-ray Absorption Near Edge, Electron Spin and Mössbauer spectroscopy) to investigate kaolin minerals (kaolinite, dickite, nacrite and halloysite) and their modifications (intercalation compounds, nanocomposites and other modifications).