X-ray fluorescence of condensed C-60 has been recorded in high resolut
ion using monochromatic synchrotron radiation excitation. Strong inten
sity modulation of constituent spectral features is observed with vary
ing excitation energy up to 10 eV above threshold. The energy dependen
ce is interpreted as due to resonant inelastic x-ray scattering, leadi
ng to symmetry selection rules governing the two-photon process in the
fully symmetric molecule.