Open AccessNew data on sulphosalts from hydrothermal siderite-type veins in the Spišsko-gemerské rudohorie Mts. (eastern Slovakia): 1. Nuffieldite and aikinite from Slovinky-Došťavná vein
Author(s) -
Martin Števko,
Jiří Sejkora,
Ľudovít Dojčanský
Publication year - 2021
Publication title -
bulletin mineralogie petrologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.239
H-Index - 10
eISSN - 2570-7345
pISSN - 2570-7337
DOI - 10.46861/bmp.29.108
Subject(s) - siderite , pyrite , ankerite , orthorhombic crystal system , hydrothermal circulation , mineralogy , chlorite , quartz , crystallography , geology , chemistry , crystal structure , seismology , paleontology
A new occurrence of nuffieldite was recently discovered in a siderite-type hydrothermal vein with sulphides in Došťavná near Slovinky, Spišsko-gemerské rudohorie Mts., Spišská Nová Ves Co., Košice Region, Slovakia. It forms lead-gray acicular crystals reaching up to 1 cm in size or aggregates up to 2.5 cm, which are enclosed in quartz-siderite matrix together with chalcopyrite, pyrite, tourmaline and chlorite. Nuffieldite is frequently replaced by minor aikinite, galena and native bismuth. The refined unit-cell parameters of nuffieldite (for the orthorhombic space group Pbnm) are: a 14.5313(16) Å, b 21.454(2) Å, c 4.0500(6) Å and V 1262.58(19) Å3. The average (n=145 analyses) empirical formula of nuffieldite from Slovinky-Došťavná based on Pb+Bi+Sb = 5 apfu is corresponding to Cu1.30Pb2.00Bi2.00(Pb0.30Bi0.30 Sb0.40)1.00(S7.12Se0.03)7.15. Aikinite forms microscopic, anhedral to subhedral grains or aggregates replacing nuffieldite. The average (n=29) empirical formula of studied aikinite based on (Cu+Pb)/2+(Sb+Bi) = 8 apfu is Pb3.83Cu3.76(Bi4.12Sb0.09)4.21(S12.40Se0.03)12.03.