A method of making a foamed glass composite, including crushing a vitreous precursor material, such as waste glass, frit, metallurgical slag or the like, sizing the crushed vitreous precursor to segregate an amount of crushed particles of a predetermined size and pelletizing the crushed particles. The pellets are preheated and passed through a high-temperature zone to foam the pellets. The foamed pellets are rapidly quenched to a temperature below their dilatometric softening point and then cooled to room temperature. The high temperature zone is at least about 1200° C. and the pellets are preheated to within no more than about 25° C. of their dilatometric softening point. The pellets are quenched to partially or completely avoid annealing and have increased hardness and compressive strength as a consequence, as well as a preferred failure mode under compression and torsional loads of crushing/shattering.