Abstract
Five specimens of “dognacskaite” from Dognecea (Caras-Severin County, Banat, Romania), a poorly described substance, once considered a Cu–Bi sulfosalt, were studied by ore microscopy, SEM, EPMA, and XRPD methods. One of the specimens is probably that used for the original description by Jozsef Krenner. Every specimen proved to be a mixture with a similar mineral composition and texture. The main component of “dognacskaite” is bismuthinite rimmed by wittichenite (containing strings of native bismuth), the latter is in turn rimmed by copper sulfides (mainly djurleite with some covellite). Emplectite can also be found occasionally in the larger voids of bismuthinite. Magnetite (in some cases oxidized), chalcopyrite, bornite (replacing chalcopyrite) and rare sphalerite and tetradymite form inclusions in bismuthinite or in the rims surrounding it. Goethite, calcite, bismuth ochre and other unspecified fine-grained products of alteration are abundant in the voids. Data from earlier studies are easily explainable on the basis of this mineral assemblage, suggesting that every specimen of “dognacskaite” is a mixture of this kind. The samples may correspond to a (pyrite–) magnetite – chalcopyrite skarn ore replaced by a post-skarn hydrothermal bismuthinite ore, later affected by supergene copper enrichment then by oxidation processes. The exact locality of “dognacskaite” cannot be determined, but at least some of the specimens have been collected in the former Petri-Pauli (or Peter-Pal), now Petrusi Pavel mine on Mt. Danilii.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.