Abstract: Using the Dolivo-Dobrovol’sky index and information-based parameters on the basis of new experimental data, the problem of the symmetry and structural complexity of the mineral substance of the deep geospheres is considered in the framework of the pyrolite model of the Earth’s mantle. It is shown that, in contrast to the previously made conclusions about the increase in the symmetry of minerals with depth, the behavior of the quantitative parameters of symmetry and structural complexity is nonlinear. The symmetry increases (and the structural complexity decreases) to the boundary of the decomposition of ringwoodite into bridgmanite and magnesiowustite (660 km), after which there is a decrease in the Dolivo-Dobrovol’sky index to 18.40 and an increase of the atomic parameter of structural complexity to 2.786 bits/atom. This behavior is determined by the uneven and opposing effect of temperature and pressure on the symmetry and structural complexity of the crystalline substance, which is caused by the nonlinear nature of the averaged geothermal gradient of the Earth’s crust and mantle. The information-based parameters of structural complexity are a more sensitive indicator of symmetry than the Dolivo-Dobrovol’sky index, which is related to the former taking into account the features of the crystal structure of particular minerals. © Pleiades Publishing, Ltd. 2024. ISSN 1028-334X, Doklady Earth Sciences, 2024. Pleiades Publishing, Ltd., 2024.