The conditions of opal formation within the North-Mutnovskaya volcanic zone of Kamchatka

The characteristics of formation of the opal mineralization in the host rock within Mut-novskaya volcanic zone were studied. The type of metasomatic rock alteration and its consecutive order were established. The results of study allowed identifying the mineral inclusions in opals, which was linked to the metalliferousness of the Mutnovsky hydro-thermal system. Probable mechanism of opals formation within the North Mutnovskaya zone is considered, and its characteristics are compared to those from the opal field Raduzhnoye, Primorye.