The disclosed simple economical and rapid sol-gel process for forming a silica-based glass body, termed the "vapogel" process, comprises introduction of a silicon halide-containing gas (eg., SiCl4 + O2) into an aqueous medium. The thus formed sol can gel within minutes, resulting in a monolithic gel body. This gel body can be dried and consolidated into a glass body or, preferably, be partitioned into particles having a relatively narrow size distribution. The thus formed particles can be used to produce a glass body such as an optical fiber preform, from which fiber can be drawn. Various techniques for forming the glass body from the gel are disclosed.; Among the many advantages of the vapogel method are its ability to produce very homogeneous mixed oxide glasses of composition not obtainable by prior art sol-gel processes, and the advantageous mechanical properties of the gel produced by the method. The latter makes possible, inter alia, formation of particles having a relatively narrow size distribution.