The geological literature has long known examples of localization of bark complex rocks or hydrothermal veins in the fractures of shear-type discontinuities. Characteristically, all the examples of fracture formation associated with horizontal flexures described in the geologic literature necessarily reflect the conditions that arise during the development of large-scale shear faults.

The considered article by P. B. Vainerman and A. S. Smirnova, in our opinion, insufficiently objectively, and in some cases geologically incorrectly reflects some questions of conditions of formation and regularities of location of Transcaucasian deposits of technical agate. In this regard, we consider it necessary to discuss these iss.s in order to exclude subjective and poorly grounded ideas, which can misdirect researchers ...

In geological literature the conditions of formation of agate deposits are covered very one-sidedly. Most of the published works devoted to the genesis of agate mainly consider the mechanism of chalcedony filling of voids in rocks and formation of agate banding. However, search criteria are necessary for finding agate deposits, which can be developed only on the basis of clear ideas about the conditions of deposit formation. The host rocks for all agate deposits in Transcaucasia are volcanogenic formations, mainly of andesite composition. Agate deposits of the Akhaltsikhe region of the Georgian SSR are localized either in glassy andesite covers or in the thickness of andesite tuffobreccia and tuffoconglomerates. In terms of age, the rocks belong to the upper middle, lower upper Eocene ...