In this work, silicon nanowires were grown on gold-coated silicon substrates by a combination of the vapor-liquid-solid (VLS) growth mechanism with thermal evaporation of silicon monoxide (SiO). The structure of the resulting nanowires was analyzed using scanning and transmission electron microscopy. The nanowires with diameters of ca. 24 to 160 nm and lengths up to several micrometers possess a crystalline silicon core and an amorphous silicon dioxide shell. The existence of a gold droplet on the nanowire tip could be verified as required by the VLS mechanism. The crystallographic growth direction as well as the influence of selected growth parameters was investigated. Based on the experimental findings, a model of the SiO-VLS growth mechanism was presented. In addition to the regular nanowires, also nanowires with periodic diameter oscillations and nanowires with periodically embedded gold/silicon nanoparticles were found and analyzed. The origin of the diameter oscillations was shown to be a self-oscillation process during nanowire growth. For the nanowires with embedded gold/silicon nanoparticles a model for a growth mechanism was proposed, based on the structural investigation. In addition, the post-growth oxidation behavior of the nanowires was investigated, showing signs of retarded oxide growth compared to planar oxidation.