Equations of State of Muscovite at High Pressures and High Temperatures

—The paper attempts to build equations of state of muscovite in the region of high pressures and high temperatures. This problem is solved by reconstructing the free energy of the crystalline and amorphous muscovite phases as analytical functions of the specific volume and temperature. Mutually consistent equations of state (thermal, caloric, Mie-Grüneisen) of each phase are constructed on the basis of general thermodynamic equations and partial derivatives of reconstructed semiempirical formulas for free energy. The reliability of the equations of state is justified by the agreement of some calculated and experimental thermophysical properties (compression, thermal expansion, bulk compression modulus, heat capacity, Hugoniot) of muscovite at pressures as high as ≈70 GPa and temperatures as high as ≈1700 K.