We have investigated the magnetism of ferrimagnetic Fe3Se4. A monoclinic Fe3Se4 powder sample was synthesized using an ampule technique. Magnetic properties were studied using 57Fe Mössbauer spectroscopy measurements. The spectra were recorded between 77 and 360 K. Fitting could be done using four spectral components: two for each iron site in the lattice, or using only two components, each with a correlated distribution of the hyperfine parameters. Using the latter method the hyperfine parameter sets for each component were obtained from two distributions, tentatively taken as the local iron charge, i.e. the spectra were analyzed assuming the presence of a modulation of the iron valence. The crystallographic 1:2 ratio of the iron sites is reflected in the intensities of the magnetic Mössbauer spectra, whether one is using two or four components, but above TC only the ”correlated” two-component fitting was successful.