Аннотация:To date, thermodynamic, semi-empirical andempirical models have been developed to predict the crystallization of olivine, plagioclase, augite, orthopyroxene and ore minerals (sulfides, chromium spinels, magnetite and ilmenite). In order to model the equilibrium in basite - hyperbasite systems, it remains to derive a thermobarometer-compositometer for pigeonite.From the Lepr 3.0 and INFOREX databases, 227 “dry” quenching experiments (51 of which are high pressure up to 30 kbar) were extracted, characterizing the compositions of coexisting pigeonites and melts. As a result of this work, a system of equations of the pigeonite thermobarometer, describing the equilibrium with the silicate melt in a wide range of compositions, temperatures, pressures and oxygen fugacity with high accuracy was developed.The liquidus thermobarometers obtained for the first time allow to predict not only the main oxides, but also secondary components (TiO2, Al2O3, MnO, Na2O, Cr2O3) in the composition of pigeonites.