Strefowość wzrostu kryształów galeny z kopalni Bolesław koło Olkusza (region śląsko-krakowski)

Abstract

Growth zones of galena crystals from the Bolesław mine near Olkusz (Silesian-Cracow region, southern Poland).S u m m a r y. Idiomorphic galena crystals occurring within Triassic dolomites from the Boles³aw mine near Olkusz were the subject of the study. The samples were collected from vein-pocket-like aggregates of galena, where two stages of mineralization were distinguished. Polished samples were etched with HCl (1:3). Etching revealed the growth zones of PbS crystals. Subsequently, decrepitation, chemical and X-ray analyses were applied. Two decrepitation effects, recorded at the maximum at 150-180°C and 250-300°C, are related to decrepitation of the two inclusion types. The chemical composition and unit cell size vary within the individual growth zones of the crystals. It can be concluded that during growth of the galena crystals the physico chemical conditions were not stable.