O żyle kruszcowej w Grudnie (Góry Kaczawskie)

Abstract

ON AN ORE-BEARING VEIN AT GRUDNO (KACZAWA MTS.)

Summary

An ore-bearing vein, so far not described in the literature, occurs in the eastern part of the Kaczawa Mts., near Grudno. Mineral composition of the vein, and textures and structures of the ores point to a great similarity to a polymetallic deposit at Stara Góra. In the rich assemblage of sulphides and sulphosalts represented by arsenopyrite, pyrite, marcasite, sphalerite, chalcopyrite, galena, boulangerite, bournonite, tetrahedrite and antimonite also both freibergerite and pyrargyrite have been enocountered, though so far unknown in the Kaczawa Mts. Microscope diagnosis of silver minerals was proved by the chemical analysis on X-ray microanalyser. Freibergite from Grudno distinguishes itself by a high content of silver, amounting to about 23 per cent. Some analogies between the paragenetic assemblage and typomorphic features of ore minerals from the vein in study, and those which are found in other veins of the Kaczawa Mts. allow that these minerals could have been formed under similar conditions and during the same process.