Chemically strengthened glass, and glass for chemical strengthening

A chemically strengthened glass, comprising, in mole percentage on an oxide basis, 58 to 70 of SiO2, 10 to 18% of Al2O3, 0 to 3% of B2O3, 0 to 2% of P2O5, 8 to 13% of Li2O, 2 to 6% of Na2O, 0.5 to 2% of K2O, more than 0% to 5% of MgO, 0 to 20% of CaO, 0 to 20% of SrO, 0 to 15% of BaO, 0 to 10% of ZnO, 0 to 1% of TiO2, and 0.5 to 2% of ZrO2, wherein:

• the chemically strengthened glass has a specific compressive stress (CS) of 450 MPa or more;
• the compressive stress value (CS90) in a portion at a depth of 90 μm from a surface of the chemically strengthened glass is 25 MPa or more, or a compressive stress value (CS100) in a portion at a depth of 100 μm from the surface is 15 MPa or more;
• and
• a value of X is 30000 or more, the value of X being calculated based on the following formula by using contents in mole percentage on an oxide basis of components of SiO2, Al2O3, B2O3, P2O5, Li2O, Na2O, K2O, MgO, CaO, SrO, BaO, and ZrO2:
• X=SiO2×329+Al2O3×786+B2O3×627+P2O5μ×(−941)+Li2O×927+Na2O×47.5+K2O×(−371)+MgO×1230+CaO×1154+SrO×733+ZrO2×51.8.