A volcanic material, pumice from the island of Tenerife (Canary Islands) has been studied and modified to be used as catalyst and catalyst support. The raw material has been subjected to several treatments; separation by density, pelletizing, thermal and acid treatment and metal impregnation. Each material obtained was tested in cumene cracking, n-pentane hydroisomerization and Claus reactions. Pumice catalyzed the cumene cracking reaction, with greater selectivity to benzene when pelletized and with greater conversion when acidified. Conversion increased and selectivity decreased as more reaction-regeneration cycles were performed. The pelletized material gave the same conversion in the Claus reaction as the industrial catalyst, coinciding with the equilibrium conversion.