Anisotropy is a typical physical property of quartz crystals, which has the following physical constants. which is: 

  ⑴, density: 2.649 g / cubic meter;

  ⑵, refractive index: 1.553 (or 1.5574), with optical rotation;

  ⑶, velocity of sound: V = E / e E is the Young's coefficient, with the direction of change has different values;

  ⑷, thermal expansion coefficient: parallel to the optical axis X = 77.10 × 10 (0 ℃) perpendicular to the optical axis X = 15.24 × 10 (0 ℃);

  ⑸, insulation performance: parallel to the optical axis R = 1 × 10 ohm. Cm perpendicular to the optical axis R = 2 × 10 ohm. Cm;

  ⑹, thermal conductivity: no Z direction than the vertical Z direction of the thermal conductivity of about twice as large;

  ⑺, elastic performance: its Young's coefficient in the cross-section is not the same.