A. V. Esaulkov, Chief Geologist e-mail: Esaulkov_AV@sgok.ru; V. V. Semenov, Deputy Chief Engineer for blasting — Head of Technical Department, Candidate of Engineering Sciences, e-mail: Semenov_VV@sgok.ru, "Stoilenskiy Mining and Concentrating Plant" Company; V. A. Dunaev, Head of Department, Professor, Doctor of Geological and Mineralogical Sciences, e-mail: viogem@mail.belgorod.ru; E. B. Yanitskyi, Senior Researcher, Candidate of Geographical Sciences, e-mail: viogem@mail.belgorod.ru; I. M. Ignatenko, Researcher, e-mail: viogem@mail.belgorod.ru, Federal State Unitary Enterprise, All-Russian Research Institute of Drainage of a Mineral Resources Deposit, Engineering Constructions Protection from Flood, Special Mining Works, Geomechanics, Geophysics, Hydrotechnics, Geology and Mine Surveying.

The relation of blockiness and strength of Precambrian rocks (iron quartz and shale rocks), which presents developing Stoilenskoe deposit has been analysed. Rock classificationdepends on categories of blastability and geometrization of different categories at quarry plan has been developed.