Glasses having high fracture toughness

A glass article, comprising:

• 50 mol % to 69 mol % SiO2;
• 12.5 mol % to 25 mol % Al2O3;
• 0 mol % to 8 mol % B2O3;
• greater than 0 mol % to 4 mol % CaO;
• greater than 0 mol % to 17.5 mol % MgO;
• 0.5 mol % to 8 mol % Na2O;
• K2O;
• 0 mol % to 2.5 mol % La2O3;
• and
• greater than 8 mol % to 18 mol % Li2O;
• wherein:
• (Li2O+Na2O+MgO)/Al2O3 is from 0.9 to less than 1.3;
• and
• Al2O3+MgO+Li2O+ZrO2+La2O3+Y2O3 is from greater than 23 mol % to less than 50 mol %.

A glass article, comprising:

• a composition at a center of the glass article comprising:
• 50 mol % to 69 mol % SiO2;
• 12.5 mol % to 25 mol % Al2O3;
• 0 mol % to 8 mol % B2O3;
• greater than 0 mol % to 4 mol % CaO;
• greater than 0 mol % to 17.5 mol % MgO;
• 0.5 mol % to 8 mol % Na2O;
• 0 mol % to 2.5 mol % La2O3;
• and
• greater than 8 mol % to 18 mol % Li2O;
• wherein:
• (Li2O+Na2O+MgO)/Al2O3 is from 0.9 to less than 1.3;
• Al2O3+MgO+Li2O+ZrO2+La2O3+Y2O3 is from greater than 23 mol % to less than 50 mol %;
• and
• the composition at the center of the glass article comprises:
• 0.5 mol % to 4 mol % CaO;
• or
• K2O,
• a compressive stress region extending from a surface of the glass article to a depth of compression.