Mineralogy of the Medieval Ag-Au occurrences Banská Belá, Treiboltz, Rabenstein, and Kopanice in the Banská Štiavnica ore district (Slovakia)
Berkh, Khulan; Majzlan, Juraj; Chovan, Martin; Kozák, Jaroslav; Bakos, František
published: Jun 1, 2014
ArtNo. ESP154019103002, Price: 29.00 €
The Medieval mining sites at Banská Belá, Kopanice, Treiboltz and Rabenstein in the Banská Štiavnica ore district (Slovakia) are epithermal Ag-Au occurrences. The mineralogy of the exploited ores has largely been unknown up to date because the richest parts of those mines were exhausted already three centuries ago. However, studies of samples from old mines and recently completed drillholes allowed us to gather new mineralogical data. In Banská Belá, the Ag minerals include acanthite, polybasite-pearceite, pyrargyrite, stephanite, rare proustite and freibergite and occur mostly as inclusions in pyrite. In Kopanice, the main Ag mineral is acanthite and the only base-metal sulfide is pyrite. Both minerals are often rimmed by unnamed AgFe(Ni) or AgSe(Te) sulfides. At Treiboltz, the dominant Ag carriers are hessite and benleonardite, both associated with galena. In Rabenstein, pyrargyrite and freibergite are the main Ag minerals. Electrum and uytenbogaardtite are present in all sites except Treiboltz. In addition, base-metal sulfides (pyrite, chalcopyrite, galena, sphalerite) may be also abundant. Base-metal sulfides are the oldest ore minerals assemblage, followed by a later hydrothermal pulse which precipitated Au-Ag minerals. Some of the precious-metal sulfides can be assigned to late secondary enrichment that most likely sustained the mining of Au and Ag for centuries.