A glass article includes: a glass phase including a first structure in which a silicon atom is covalently bonded to four first oxygen atoms; and a plurality of crystals dispersed in the glass phase. The crystals include beta-quartz crystals, each of the beta-quartz crystals includes the first structure and a second structure in which aluminum is covalently bonded to four second oxygen atoms, and a crystallinity of the beta-quartz crystals is in a range of about 40% to about 50%.