Abstract: A process is described in which hollow spheres or hollow-sphere composites (moldings) having high-strength walls are produced. Additional layers are applied to metallized spherical lightweight particles having a core of foamed polymer. In order to increase the strength of the wall of the spherical particle and the strength of the molding, metallized lightweight spherical particles having a metal wall thickness of 5 to 20 microns are treated (coated) with a dispersion of particulate metal or metal oxide or particulate ceramic or refractory material, the lightweight spherical particles coated in a thickness from 15 to 500 microns are dried, the dried particles are heated to a temperature of about 400.degree. C. to effect a pyrolysis of the polymer core, and the particles are subsequently sintered at a temperature from 900.degree. to 1400.degree. C.