In situ high-pressure neutron diffraction will be used to investigate the pressure-induced transformation of the Al coordination environment in a prototypical aluminosilicate glass at pressures up to 18 GPa. This element is an essential component in commercial display glass, where pressures in the gigapascal regime are easily generated by sharp-contact loading, and it is also an important component in magma-related glasses such as those from the CaO-MgO-Al2O3-SiO2 (CMAS) system. The pressure-induced conversion of tetrahedral AlO4 units into higher coordinated structural motifs will change the glass structure and the related material properties. It is important to investigate these processes in situ, in order to aid in the development of realistic models for, e.g., crack formation and propagation in display glass and related materials.