The aim of this article is to study the nature of the defects arising on the surface of silica glass during mechanical processing followed by chemical cleaning and etching. Such defects manifest themselves as a narrow Raman peak near 85 cm–1. It is shown that chemical etching of the ground surface of silica glass leads to the formation of microcrystalline defects embedded at the depth of the near-surface layer. Defects of this kind create heterogeneities in the structure of the atomic network and increase internal friction in silica glass mechanical resonators. This phenomenon should be taken into account when developing the technology for fabrication of high-Q resonators.