Next Article in Journal
Lead Recovery from Solid Residues of Copper Industry Using Triethylenetetramine Solution
Previous Article in Journal
Mechanical Performance of Concrete Exposed to Sewage—The Influence of Time and pH
Article

Tamuraite, Ir5Fe10S16, a New Species of Platinum-Group Mineral from the Sisim Placer Zone, Eastern Sayans, Russia

1
Research Laboratory of Industrial and Ore mineralogy, Cherepovets State University, 5 Lunacharsky Avenue, 162600 Cherepovets, Russia
2
V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Science, 3 Avenue Prospekt Koptyuga, 630090 Novosibirsk, Russia
3
Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC H3A 0E8, Canada
4
Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
*
Author to whom correspondence should be addressed.
Academic Editor: Ulf Hålenius
Received: 18 April 2021 / Revised: 13 May 2021 / Accepted: 17 May 2021 / Published: 20 May 2021
Tamuraite, ideally Ir5Fe10S16, occurs as discrete phases (≤20 μm) in composite inclusions hosted by grains of osmium (≤0.5 mm across) rich in Ir, in association with other platinum-group minerals in the River Ko deposit of the Sisim Placer Zone, southern Krasnoyarskiy Kray, Russia. In droplet-like inclusions, tamuraite is typically intergrown with Rh-rich pentlandite and Ir-bearing members of the laurite–erlichmanite series (up to ~20 mol.% “IrS2”). Tamuraite is gray to brownish gray in reflected light. It is opaque, with a metallic luster. Its bireflectance is very weak to absent. It is nonpleochroic to slightly pleochroic (grayish to light brown tints). It appears to be very weakly anisotropic. The calculated density is 6.30 g·cm−3. The results of six WDS analyses are Ir 29.30 (27.75–30.68), Rh 9.57 (8.46–10.71), Pt 1.85 (1.43–2.10), Ru 0.05 (0.02–0.07), Os 0.06 (0.03–0.13), Fe 13.09 (12.38–13.74), Ni 12.18 (11.78–13.12), Cu 6.30 (6.06–6.56), Co 0.06 (0.04–0.07), S 27.23 (26.14–27.89), for a total of 99.69 wt %. This composition corresponds to (Ir2.87Rh1.75Pt0.18Ru0.01Os0.01)Σ4.82(Fe4.41Ni3.90Cu1.87Co0.02)Σ10.20S15.98, calculated based on a total of 31 atoms per formula unit. The general formula is (Ir,Rh)5(Fe,Ni,Cu)10S16. Results of synchrotron micro-Laue diffraction studies indicate that tamuraite is trigonal. Its probable space group is R3m (#166), and the unit-cell parameters are a = 7.073(1) Å, c = 34.277(8) Å, V = 1485(1) Å3, and Z = 3. The c:a ratio is 4.8462. The strongest eight peaks in the X-ray diffraction pattern [d in Å(hkl)(I)] are: 3.0106(216)(100), 1.7699(420)(71), 1.7583(2016)(65), 2.7994(205)(56), 2.9963(1010)(50), 5.7740(102)(45), 3.0534(201)(43) and 2.4948(208)(38). The crystal structure is derivative of pentlandite and related to that of oberthürite and torryweiserite. Tamuraite crystallized from a residual melt enriched in S, Fe, Ni, Cu, and Rh; these elements were incompatible in the Os–Ir alloy that nucleated in lode zones of chromitites in the Lysanskiy layered complex, Eastern Sayans, Russia. The name honors Nobumichi Tamura, senior scientist at the Advanced Light Source of the Lawrence Berkeley National Laboratory, Berkeley, California. View Full-Text
Keywords: tamuraite; platinum-group mineral; PGE sulfide; iridium–iron sulfide; Sisim Placer Zone; River Ko deposit; Lysanskiy layered complex; Eastern Sayans; Russia tamuraite; platinum-group mineral; PGE sulfide; iridium–iron sulfide; Sisim Placer Zone; River Ko deposit; Lysanskiy layered complex; Eastern Sayans; Russia
Show Figures

Figure 1

MDPI and ACS Style

Barkov, A.Y.; Tolstykh, N.D.; Martin, R.F.; McDonald, A.M. Tamuraite, Ir5Fe10S16, a New Species of Platinum-Group Mineral from the Sisim Placer Zone, Eastern Sayans, Russia. Minerals 2021, 11, 545. https://0-doi-org.brum.beds.ac.uk/10.3390/min11050545

AMA Style

Barkov AY, Tolstykh ND, Martin RF, McDonald AM. Tamuraite, Ir5Fe10S16, a New Species of Platinum-Group Mineral from the Sisim Placer Zone, Eastern Sayans, Russia. Minerals. 2021; 11(5):545. https://0-doi-org.brum.beds.ac.uk/10.3390/min11050545

Chicago/Turabian Style

Barkov, Andrei Y., Nadezhda D. Tolstykh, Robert F. Martin, and Andrew M. McDonald 2021. "Tamuraite, Ir5Fe10S16, a New Species of Platinum-Group Mineral from the Sisim Placer Zone, Eastern Sayans, Russia" Minerals 11, no. 5: 545. https://0-doi-org.brum.beds.ac.uk/10.3390/min11050545

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop