[en] The study aimed to characterize materials obtained from the melted mixture containing marble and granite wastes, and also chemical reagents. Using the characterization results was defined the feasibility of reuse of the marble and granite wastes, through the incorporation in the raw material to produce glass wool (a material with great consumer market as thermo-acoustic insulator). The batch was poured in a water-filled recipient and also in a Herty viscometer at temperatures of 1400, 1450 and 1500 °C. Samples of produced materials were characterized by morphology using Scanning Electron Microscopy, by atomic structure using X-ray Diffraction, and by thermal behavior using Differential Thermal Analysis. The total amount of marble and granite wastes can reach about 79% replacement in relation to the total weight of the raw material used in the glass wool production. (author)