A detailed study of morphological, compositional and structural aspects of Sr(2)RuO(4)-Sr(3)Ru(2)O(7) eutectic crystals is reported. The stoichiometry of the phases that compose the crystals and how they are arranged in the crystals are studied. Understanding the behavior at the Sr(2)RuO(4)-Sr(3)Ru(2)O(7) interface represents a necessary prerequisite for the analysis of the experimental results on the transport properties recently reported in the literature.