Platiniferous tetra-auricupride: a case study from the Bolshoy Khailyk Placer Deposit, Western Sayans, Russia
- Tetra-auricupride, ideally AuCu, represents the only species showing the coexistence of Au with an elevated level of Pt, as in the case of a detrital grain studied structurally for the first time, from an ophiolite-associated placer at Bolshoy Khailyk, western Sayans, Russia. We infer that tetra-auricupride can incorporate as much as ~30 mol. % of a “PtCu” component, apparently without significant modification of the unit cell. The unit-cell parameters of platiniferous tetra-auricupride are: a 2.790(1) Å, c 3.641(4) Å, with c/a = 1.305, which are close to those reported for ordered AuCu(I) in the system Au–Cu, and close also to the cell parameters of tetraferroplatinum (PtFe), which both appear to crystallize in the same space group, P4/mmm. These intermetallic compounds and natural alloys are thus isostructural. The closeness of their structures presumably allows Pt to replace Au atoms so readily. The high extent of Cu + Au enrichment is considered to be a reflection of geochemical evolution and buildup in levels of the incompatible Cu and Au with subordinate Pt in a remaining volume of melt at low levels of fO2 and fS2 in the system.
Author: | Andrei Yu Barkov, Nobumichi Tamura, Gennadiy I. Shvedov, Camelia V. Stan, Chi Ma, Björn WinklerORCiDGND, Robert F. Martin |
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URN: | urn:nbn:de:hebis:30:3-571610 |
DOI: | https://doi.org/10.3390/min9030160 |
ISSN: | 2075-163X |
Parent Title (German): | Minerals |
Publisher: | MDPI |
Place of publication: | Basel |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2019/03/07 |
Date of first Publication: | 2019/03/07 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2021/01/06 |
Tag: | Bolshoy Khailyk placer; Pt-for-Au substitution; Russia; gold; ophiolite; platiniferous tetra-auricupride; platinum; western Sayans |
Volume: | 9 |
Issue: | Article 160 |
Page Number: | 10 |
HeBIS-PPN: | 477813607 |
Institutes: | Geowissenschaften / Geographie / Geowissenschaften |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Sammlungen: | Universitätspublikationen |
Licence (German): | Creative Commons - Namensnennung 4.0 |