Heavy ions frequently appear as minor components in space plasmas, for example in the solar wind and in the vicinity of comets. Both the different components of ions and the associated plasma waves are observed by extraterrestrial in situ measurements. The influence of these ion components on the properties of plasma waves is investigated by means of the multi-fluid equations. The linear mode analysis is performed numerically for a three-component plasma with an ambient magnetic field. Both the dispersion relations and the polarizations of the freely propagating wave modes are given and subsequently discussed.