Crystallized glass substrate for information recording medium

1. Field of the Invention Crystallized glasses for data recording media such as magnetic disks are provided, comprising 42-65 mol % SiO, 11-25 mol % AlO, 15-33 mol % MgO and 5.5-13 mol % TiOor 58-80 mol % SiO+AlOwith MgO/(SiO+AlO) being in the range of 0.125-0.55, wherein major crystals or crystals present at 50% by volume or more comprise -quartz solid solution or quartz-based crystals and enstatite and/or enstatite solid solution, or quartz-based crystals having a diffraction pattern almost comparable to that unique to quartz in the X-ray diffraction pattern and enstatite and/or enstatite solid solution and wherein the specific gravity is 2.9 g/cmor more. Said glass substrates have high Young's modulus, strength and heat resistance and excellent surface smoothness and surface homogeneity, and can be easily prepared.