Heat capacity \( C_{\text{p}}^{^\circ } \)(T) of crystalline magnesium zirconium phosphate was measured between 6 and 815 K. The experimental data obtained were used to calculate the standard thermodynamic functions \( C_{\text{p}}^{^\circ } \)(T), H°(T) − H°(0), S°(T), G°(T) − H°(0) over the temperature ranging from T → 0 to 810 K and standard entropy of formation at 298.15 K. The fractal dimension of Mg0.5Zr2(PO4)3 was calculated from experimental data on the low-temperature (6 ≤ T/K ≤ 50) heat capacity, and the topology of the phosphate’s structure was estimated. Thermodynamic properties of structurally related phosphates M0.5Zr2(PO4)3 (M = Mg, Ca, Sr, Ba, Ni) were compared.