In this work, several zeolitic materials were prepared by geological and waste materials activation using potassium hydroxide as activating agent. The alkaline reaction was done by the classic hydrothermal treatment method at a o constant temperature of 100 C and autogenous pressure. The synthetic products were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analyses. Different poorly crystalline zeolite-like materials were obtained, including K-chabazite (CHA), zeolite K-F (EDI), hydroxysodalite (SOD) and K-phillipsite (PHI). The K+ ion is a suppression factor during zeolite synthesis, which causes a slow crystallization rate, revealing a low conversion efficiency of the starting materials in KOH solutions. Palabras Claves: Zeolitization, Geological and waste materials, Potassium hydroxide, Zeolite-like materials Resumen