The article presents the results of a complex study of the relicts of the primary magmatic spinels from the Archean (3.0-2.7 Ga) komatiitic series of the greenstone structures of the eastern Fennoscandian Shield. The accessory minerals of the massive and mesocumulate zones of differentiated komatiite flows (containing 24-30 wt. % MgO) are analyzed. The coexistence of several generations of spinels including relicts of the primary magmatic chromite-alumochromite (Cr2O3 44.64-51.80, AI2O3 9.39-13.74, #Cr 68.97-78.52, #Mg 3.98-12.14, #Fe 5 kbar and temperatures > 500 °C leads to a complete recrystallization of the primary spinels.