Quartz | Definition, Types, Uses, Facts | Britannica
Quartz exists in two forms: (1) alpha, or low, quartz, which is stable up to 573 °C (1,063 °F), and (2) beta, or high, quartz, stable above 573 ° two are closely related, with only small movements of their constituent atoms during the alphabeta transition. The structure of betaquartz is hexagonal, with either a left or righthanded symmetry group equally populated in crystals.