Structure of natural volcanic glasses: diffraction versus spectroscopic perspective

Current research on the structure of natural volcanic glasses carried out over the last 10–20 years is reviewed with special attention being given to X-ray diffraction, neutron diffraction and Raman spectroscopy as well as to several element-specific spectroscopic methods (NMR, XANES, EXAFS, time-resolved luminescence and Mössbauer spectroscopy). The main challenges in the structural study of natural volcanic glasses, the understanding of the interplay between the network topology and the local coordination of the network-modifier cations as well as possible future developments are discussed.