This analysis considers only the electronic polarizability, neglecting the ionic contribution that is present when particles are dispersed in a matrix. Still, the results provide a clear justification for using the volume model for describing polarizability. The following sections evaluate the suitability of such a model for treating anisotropic gas-phase particles and particles embedded in host matrices to determine the transferability of fitted permittivities, and the importance of particle shapes and volumes in the polarization behavior of each.