Unusual extinction profiles by Rayleigh scattering

The extinction efficiencies for small smooth metallic particles (granules) have been calculated using rigorous Mie theory of scattering. Strong size dependent resonances for spheres composed of sodium, potassium, and calcium have been found. The results seem to have relevance to the problems of interstellar grains especially with reference to structures in the observed extinction curve, diffuse bands and anomaly of cosmic abundances of elements. (author)