Synthetic perovskite (Mg, Fe) SiO3 prepared in a diamond anvil high pressure cell at 375 kbar and 1000 ¿C has been examined in transmission electron microscopy and selected area diffraction. The crystals grow, probably by nucleation and growth, as small lozenge platelets on {111} planes of the pseudo cubic ideal cell. The diffraction patterns are compatible with a pseudo tetragonal cell with parameters twice as large as those previously determined by X-ray diffraction.