The structure and properties of glasses and melts in the MgO-Al₂O₃-SiO₂ (MAS) and CaO-MgO-Al₂O₃-SiO₂ (CMAS) systems play an important role in Earth and material sciences. Aluminum has a crucial influence in these systems, and its environment is still questioned. In this paper, we present new results using Raman spectroscopy and ²⁷Al nuclear magnetic resonance on MAS and CMAS glasses. We propose an Al/Si tetrahedral distribution in the glass network in different Qⁿ species for silicon and essentially in Q⁴ and ^VAl for aluminum. For the CMAS glasses, an increase of ^VAl and ^VIAl is clearly visible as a function of the increase of Mg/Ca ratio in the (Ca,Mg)₃Al₂Si₃O₁₂ (garnet) and (Ca,Mg)AlSi₂O₈ (anorthite) glass compositions. In the MAS system, the proportion of ^VAl and ^VIAl increases with decreasing SiO₂ and, similarly with calcium aluminosilicate glasses, the maximum of ^VAl is located in the center of the ternary system.

ID21 beamline (ESRF) offers combination of μXRF, μXANES (2.0–9.1 keV), μXRD and μFTIR, increasingly used to analyse artistic and ancient materials.