A method for manufacturing a glass composition including a host glass, a 3p component having a concentration of about 5 mole percent to about 10 mole percent, and at least one of a 6p component having a concentration of about 1 mole percent to about 5 mole percent and a 5p component having a concentration of about 1 mole percent to about 5 mole percent, is provided. The method includes heating the host glass to a first predetermined temperature for a first period of time; mixing a powder including the 3p component and the at least one of the 5p component and the 6p component with the heated host glass into a glass/powder mixture; heating the glass/powder mixture to a second predetermined temperature for a second period of time; and cooling, after heating, the glass/powder mixture.