Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Jaszczakite, [(Bi,Pb) (sub 3) S (sub 3) ][AuS (sub 2) ], a new mineral species from Nagyborzsony, Hungary

Luca Bindi and Werner H. Paar
Jaszczakite, [(Bi,Pb) (sub 3) S (sub 3) ][AuS (sub 2) ], a new mineral species from Nagyborzsony, Hungary (in Chromitites, platinum-group elements, and ore minerals; special issue dedicated to Zdenek Johan (1935-2016), Vojtech Ettler (prefacer) and Reto Giere (prefacer))
European Journal of Mineralogy (August 2017) 29 (4): 673-677

Abstract

Jaszczakite, [(Bi,Pb) (sub 3) S (sub 3) ][AuS (sub 2) ], represents another new species from the abandoned Nagyborzsony Au deposit at Also-Rozsa, northern Hungary. The mineral is closely associated with arsenopyrite, pyrite, marcasite, sphalerite, chalcopyrite, gold, bismuth, bismuthinite, ikunolite, jonassonite, and cosalite, in a matrix of quartz. It is opaque, tin-white, has a metallic lustre and a black streak. Jaszczakite is brittle, and the fracture is irregular. Neither cleavage nor parting are observable in the section. The VHN (sub 5) value ranges between 115 and 132 (mean 122) kg mm (super -2) which corresponds to a Mohs hardness of 21/2-3. The calculated density is 7.327 g cm (super -3) In plane-polarized light jaszczakite is weakly bireflectant and pleochroic from light grey to a slightly bluish grey. Internal reflections are absent. The mineral is distinctly anisotropic with rotation tints very similar to those of jonassonite (shades of green and purple). The reflectance COM values (air, R (sub 1) and R (sub 2) in %) are: 49.4, 50.9 (471.1 nm); 47.1, 48.8 (548.3 nm); 46.5, 47.7 (586.6 nm); 48.8, 49.5 (652.3 nm). The average result of five electron-microprobe analyses is Au 19.90(34), Ag 0.22(3), Bi 46.29(54), Pb 16.50(26), Cd 0.11(3), Sb 0.12(4), As 0.08(3), S 16.17(30), Se 0.16(6), total 99.55 wt%. The empirical formula (based on 9 atoms pfu) is Au (sub 1.00) Ag (sub 0.02) Bi (sub 2.18) Pb (sub 0.78) Cd (sub 0.01) Sb (sub 0.01) As (sub 0.01) S (sub 4.97) Se (sub 0.02) or, according to the refinement results, [(Bi (sub 2.18) Pb (sub 0.78) Ag (sub 0.02) Cd (sub 0.01) Sb (sub 0.01) As (sub 0.01) ) (sub Sigma =3.01) S (sub 3) ][AuS (sub 2) ]. The simplified formula is AuBi (sub 3) S (sub 5) , which requires Au 20.01, Bi 63.70, S 16.29, total 100.00 wt%. Jaszczakite is orthorhombic, space group Pmmn, with unit-cell parameters: a = 3.858(1), b = 12.552(3), c = 9.289(2) A, V = 449.83(8) A (super 3) , a:b:c = 0.3074:1:0.7400, Z = 2. The five strongest observed X-ray powder-diffraction lines [d in A (I/I (sub 0) ) (hkl)] are: 7.466 (100) (011), 6.2760 (90) (020), 5.2003 (24) (021), 3.0963 (68) (003), 2.7768 (26) (023). The crystal structure showed that jaszczakite is the S-Bi-analogue of buckhornite [Pb (sub 2) BiS (sub 3) ][AuTe (sub 2) ]. Jaszczakite is named in honour of John A. Jaszczak, Professor of Physics at the Michigan Technological University, for his significant contributions on the complexities of natural graphite.


ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 29
Serial Issue: 4
Title: Jaszczakite, [(Bi,Pb) (sub 3) S (sub 3) ][AuS (sub 2) ], a new mineral species from Nagyborzsony, Hungary
Title: Chromitites, platinum-group elements, and ore minerals; special issue dedicated to Zdenek Johan (1935-2016)
Author(s): Bindi, LucaPaar, Werner H.
Author(s): Ettler, Vojtechprefacer
Author(s): Giere, Retoprefacer
Affiliation: Universita degli Studi di Firenze, Dipartimento di Science de la Terra, Florence, Italy
Affiliation: Charles University, Prague, Czech Republic
Pages: 673-677
Published: 201708
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Germany
References: 12
Accession Number: 2017-090046
Categories: Mineralogy of non-silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 5 tables
N47°55'60" - N47°55'60", E18°49'60" - E18°49'60"
Secondary Affiliation: CNR, Istituto di Geoscienze e Georisorse, AUT, Austria
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Schweizerbart'sche Verlagsbuchhandlung. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201747
Close Modal

or Create an Account

Close Modal
Close Modal