The electrical conductivity of meteoritic majorite, measured at 10 Hz under a nitrogen atmosphere at ambient pressure, is 3.8(¿1.8)¿10-7 S/m at room temperature and displays an Arrhenius behavior with an activation energy of 0.55(¿0.1) eV over the temperature range 290--370 K. Extrapolating these values to conditions of the Earth's mantle suggests that majorite and spinel can account for the increase in electrical conductivity observed from the upper mantle to the transition zone, where these phases are stable. ¿ American Geophysical Union 1995