Experimental investigation of P-wave velocity, density, and elasticity (<i>C</i>11) during the α–β phase transition in quartz

The variations in P-wave velocity and volume during the α–β phase transition of single-crystal quartz were investigated under pressures ranging from 0.01 to 2.00 GPa and temperatures from room temperature to 1100 °C. These measurements facilitated the development of the α–β phase transition diagram of quartz and the calculation of its elasticity (C11). The results indicated that the α–β phase transition temperature of quartz increases linearly with pressure, with a gradient of 2.5 °C/MPa, providing a precise calibration point for geothermal profiles at substantial depths. Furthermore, the elasticity of quartz was determined based on precise measurements of P-wave velocity and density during the α–β phase transition, offering valuable insights into the underlying causes of geophysical anomalies in the Earth’s interior.