Recently, we have described a multigram preparation of tungsten trioxide/amorphous silica (for brevity -WO3/a-SiO2) fibers, which served as a precursor material for the preparation of polycrystalline tungsten metal nanofibers and WS2 microfibers. In both cases, amorphous SiO2 acted as a binder of the material nanograins. During the reduction of WO3 fibers to metallic tungsten, several reduction processes have been observed with varying compositions and morphologies.