Ion exchangeable glass compositions having improved mechanical durability

A glass article comprising:

• greater than or equal to about 70 mol % and less than or equal to about 90 mol % SiO2;
• greater than or equal to about 2 mol % and less than or equal to about 9 mol % Al2O3;
• greater than or equal to about 5 mol % and less than or equal to about 15 mol % Li2O;
• greater than or equal to about 0 mol % and less than or equal to about 10 mol % Y2O3;
• greater than or equal to about 0 mol % and less than or equal to about 9 mol % Ta2O5;
• greater than or equal to about 0 mol % and less than or equal to about 10 mol % La2O3;
• and
• greater than or equal to about 0.05 mol % and less than or equal to about 1 mol % SnO2, wherein, Y2O3+Ta2O5+La2O3 is greater than or equal to about 2 mol % and less than or equal to about 15 mol %.

A method of forming a glass article, the method comprising:

• heating a glass composition, the glass composition comprising:
• greater than or equal to about 70 mol % and less than or equal to about 90 mol % SiO2;
• greater than or equal to about 2 mol % and less than or equal to about 9 mol % Al2O3;
• greater than or equal to about 5 mol % and less than or equal to about 15 mol % Li2O;
• greater than or equal to about 0 mol % and less than or equal to about 10 mol % Y2O3;
• greater than or equal to about 0 mol % and less than or equal to about 9 mol % Ta2O5;
• greater than or equal to about 0 mol % and less than or equal to about 10 mol % La2O3;
• and
• greater than or equal to about 0.05 mol % and less than or equal to about 1 mol % SnO2, wherein, Y2O3+Ta2O5+La2O3 is greater than or equal to about 2 mol % and less than or equal to about 15 mol %;
• and
• cooling the glass composition to form the glass article.