The present invention relates to a glass composition comprising 65 to 72 wt-% SiO2, at least 10.1 wt-% Li2O and at least 10.1 wt-% Al2O3 based on the total weight of the composition, the proportion of Li2O to Al2O3 being from 1:1 to 1.5:1, wherein the glass composition further comprises 0 to 2 wt-% K2O, 1 to 4 wt-% Na2O, 0 to 1.5 wt-% CaO, 0 to 1.0 wt-% MgO, 0 to 1.5 wt-% B2O3, 0 to 1.5 wt-% CeO2, 1 to 5 wt-% P2O5, 0 to 3 wt-% CaF2, 0 to 2.0 wt-% AlF3, 0 to 1.0 wt-% Ag, 0 to 5 wt-% ZrO2 and 0 to 4 wt-% TiO2 based on the total weight of the composition.
