The effect of anisotropy on cross section spectra of uniaxial spherical particles small compared to the wavelength

•Effect of material anisotropy on cross section spectra of small particles is investigated.•FDTD-spectra of anisotropic materials are compared to Mie-spectra.•Absorption, scattering, extinction is influenced in different ways.•Effect of anisotropy strongly dependent on geometry.•No range of validity can be given for 1/3–2/3-approximation.