Abstract: A composite, sintered, spherical pellet and a method for its manufacture are described. The pellet is prepared from at least one uncalcined or partially calcined ingredient selected from the group consisting of clay and bauxite materials, dust collector fines and alumina. The pellet may have an alumina-to-silica ratio from about 9:1 to about 1:1. The pellet has a specific gravity of less than 3.40. Use of such pellets in propping hydraulically fractured subterranean formations is also described.