Solid solution fisnhesserite-naumannite (Ag,Au)2Se in ores of the volcanogenic gold deposit Ozernovskoye, Kamchatka

Abstract

An abundance of tellurium and selenium in the ores of the many volcanogenic hydrothermal gold and gold‐ silver deposits (epithermal) is their peculiar feature. Among such deposits is the Ozernovskoye deposit located in the north of the Kamchatka Peninsula. Gold-bearing poor sulfide quartz, dickite‐quartz, and hydromica‐quartz veins and stockworks of the Ozernovskoye deposit occur among the secondary quartzites and argillisites and are connected with basalt‐andesite‐dacite volcanogenic bodies of Neogenic age [2]. Chalcedony-like quartz and textures of manifold brecciation are characteristic of the ores. Significant amounts of pyrite and zinc‐tennantite, copper‐ zinc tennantite‐tetrahedrite selenium-containing and poor in Te and Bi, occur in the early mineral associations (nomenclature of fahlores is given after [4]). Complex zoned zinc‐copper selenium-containing Tetetrahedrite and goldfieldite and copper and seleniumcontaining Te-tennantite, Te-tetrahedrite, and goldfieldite often enriched in Bi [7, 8] occur among the later mineral associations. Later associations contain segregations of goldfieldite, that are homogenous in composition or spotted and often arsenic-containing. The paragenesis of sylvanite AuAgTe 4 , native Te, and skippenite Bi 2 TeSe 2 is characteristic of the Ozernovskoye deposit column of ore [9]. In the parts of the deposit with the presence of abundant native tellurium, products of tellurium replacement of fahlores (arsenicum tellurantimony (Sb,As) 2 Te 3 and tellurides of copper: vulcanite and rickardite) occur [5]. The youngest and low-temperature mineralization represented by realgar and native arsenic occurs at the flanks of the Ozernovskoye orebodies.