Gladkovskyite, MnTlAs 3 S 6 , a new thallium sulfosalt from the Vorontsovskoe gold deposit, Northern Urals, Russia

Journal of Geosciences

article

Anatoly V. Kasatkin¹  E Makovicky²  Jakub Plasil³  Radek Skoda⁴  Nikita V. Chukanov⁵  Sergey Y. Stepanov⁶  Atali A. Agakhanov¹  Fabrizio Nestola⁷ 

[1] Fersman Mineralogical Museum of Russian Academy of Sciences;Department of Geoscience and Resource Management, University of Copenhagen;Institute of Physics, Academy of Sciences of the Czech Republic v.v.i;Department of Geological Sciences, Faculty of Science, Masaryk University;Institute of Problems of Chemical Physics, Russian Academy of Sciences;Zavaritsky Institute of Geology and Geochemistry;Dipartimento di Geoscienze, Università di Padova

关键词: gladkovskyite;    new mineral;    sulfosalt;    crystal structure;    Vorontsovskoe gold deposit;    Northern Urals;   

DOI  :  10.3190/jgeosci.290

学科分类：自动化工程

来源: Ceska Geologicka Spolecnost / Czech Geological Society

【 摘 要 】

Gladkovskyite (IMA2018-098), MnTlAs3S6, is a new sulfosalt from the Vorontsovskoe gold deposit, Sverdlovsk Oblast’,Northern Urals, Russia. The new mineral occurs in limestone breccias cemented by abundant realgar, orpiment, baryteand pyrite, as well as minor clinochlore, fluorapatite, quartz and talc. Gladkovskyite forms long-prismatic crystals andgrains up to 0.2 mm; it has dark cherry-red color and red streak. It is transparent with adamantine luster. The Vickersmicrohardness is 94 kg/mm2. The new mineral is brittle, with uneven fracture; neither cleavage nor parting was observed.The density calculated based on the empirical formula is 4.356 g/cm3. In reflected light, gladkovskyite is grayish-white,strongly anisotropic with rotation tints varying from light-grey to brown. Its pleochroism is moderate, from orange-red todark-red, and bireflectance is very weak, ∆R = 0.58 % (589 nm). The empirical formula of gladkovskyite is Mn1.01Tl0.99Pb0.01As2.86Sb0.13S6.00 (based on 11 atoms pfu). Prominent features in the Raman spectrum include bands of Mn–S and As–Sstretching vibrations as well as numerous low-frequency bands related to phonons. Gladkovskyite is trigonal, R31c, a =9.6392(2), c = 6.4560(15) Å, V = 519.49(12) Å3 and Z = 2. The seven strongest powder X-ray diffraction lines are [dobs, Å(I, %) (hkl) ]: 5.11 (80) (101), 4.83 (70) (110), 3.49 (50) (201), 3.23 (30) (002), 2.86 (100) (–2–11, 211), 2.68 (30) (112),2.55 (60) (301, 202). The crystal structure of gladkovskyite was refined from the single-crystal X-ray diffraction data toR = 0.0178 for 679 observed reflections with Iobs > 3σ(I). It contains infinite chains of face-sharing MnS6 octahedra, TlS9polyhedra and pyramidal AsS3 groups; the structure belongs to the group of seldom occurring cyclic sulfosalts. The newmineral honors Russian geologist Boris Aleksandrovich Gladkovsky who discovered the Vorontsovskoe gold deposit.

【 授权许可】

CC BY