Abstract: A support or base for low-vibration mounting of machines or the like is made by hardening a molding material in a mold. The base contains a hardened inorganic material with a density of 2.2 to 3.0, particularly 2.5 to 2.7 g/cm.sup.3, is made from(a) 15 to 30 weight % of an aqueous 30 to 65% potassium hydroxide-potassium silicate solution in which the SiO.sub.2 :K.sub.2 O molar ratio is 1.0 to 2.0:1;(b) 15 to 35 weight % of an oxide mixture containing amorphous SiO.sub.2 and aluminum oxide and/or hydrated amorphous silicic acid in the dispersed powder form and/or metakaolin;(c) 45 to 65 weight % of inorganic particulate fillers.The potassium silicate solution can be made by dissolving hydrated amorphous silicic acid in potassium hydroxide or its aqueous solution, and in this case, component (b) can consist entirely or partially of metakaolin.