he present work aims to analyze the effectiveness of natural zeolites for the concentration of certain elements in the rare earth group, as well as some associated cations. The work has been centered on four samples of natural zeolites from Cuba that are characterized by physical, chemical and mineralogical methods, which confirm their membership to the mordenite zeolite family, except one that was discarded in the exchange tests because it belonged to the heulandite family. The elements exchange tests were carried out over a period of 168 hours with the cations: Y3+, Eu3+, Yb3+, Ba2+, Pb2+, Cu2+ y Ni2+. Initial concentrations were set based on the average cation exchange capacity of the zeolite samples. It was concluded that this family of zeolites did not have the utility sought, because its composition contained some of the selected elements, resulting in a leaching of these cations
