Open AccessMinerály řady ullmannit - gersdorffit v asociaci s milleritem z haldy dolu Lill v Příbrami (Česká republika)
Author(s) -
Jiří Sejkora,
Jakub Plášil,
Jiří Špalek,
Pavel Škácha
Publication year - 2020
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.28.203
Subject(s) - acicular , crystallography , formula unit , mineralogy , chemistry , materials science , crystal structure , microstructure
Minerals of the ullmannite–gersdorffite solid-solution was found at mine dump material from the Lill mine, the Černojamské ore deposit, Příbram, central Bohemia, Czech Republic. It forms grey groups of idiomorphic crystals up to 0.5 mm across with metallic luster on millerite crystals. It is strongly chemically zoned, from As-rich ullmannite to gersdorffite with variable Sb contents. Its unit-cell parameter, a 5.7728(13) Å and V 192.37(7) Å3, was refined from single-crystal X-ray data. Groups of acicular millerite crystals up to 4 mm in length and formula (Ni0.97Co0.03)Σ1.00S1.01 and very rare siegenite grains up to 80 μm and formula Co1.00(Ni1.66Co0.24Fe0.02)Σ1.92S4.09 were found in association.