The first results on the interaction between an Fe–Ni melt and anthracene (С14Н10) in the presence of olivine at 3 GPa and 1500°С and on the study of the component composition of the fluid generated in this process are presented. The stability of aliphatic hydrocarbons in the implemented conditions is confirmed experimentally. It is established that, under these conditions, crystallization of high-magnesian olivines occurs (Fo = 97–98 mol %). The composition of the fluid is similar to the composition of the fluid from inclusions in synthetic diamonds. The conditions implemented in the experiment might have occurred at the early stages of the Earth’s evolution.