Kufahrite, PtPb, a new mineral from Ledyanoy Creek placer, Galmoenan ultramafic complex, Koryak Highlands, Russia
| Autor: | Valery M. Chubarov, Elena I. Sandimirova, E. G. Sidorov, Anna Vymazalová, Atali A. Agakhanov, Anton V. Kutyrev, Elena S. Zhitova, Andrey A. Zolotarev |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Placer mining
Materials science 010504 meteorology & atmospheric sciences Spinel chemistry.chemical_element engineering.material 010502 geochemistry & geophysics 01 natural sciences Crystallography chemistry Geochemistry and Petrology Ultramafic rock Vickers hardness test Nickeline engineering Mohs scale of mineral hardness Iridium Platinum 0105 earth and related environmental sciences |
| Zdroj: | Mineralogical Magazine. 85:254-261 |
| ISSN: | 1471-8022 0026-461X |
| DOI: | 10.1180/mgm.2021.18 |
| Popis: | Kufahrite, PtPb, is a new mineral (IMA2020-045) from the Ledyanoy Creek placer, Koryak Highlands, Russia. The mineral was found in isoferroplatinum (Pt3Fe) grains extracted from a heavy-mineral concentrate, together with tetraferroplatinum (PtFe), tulameenite (Pt2FeCu), native iridium, hollingworthite (RhAsS) and Cr-rich spinel. Kufahrite occurs as part of alteration rims which are formed together with tetraferroplatinum after isoferroplatinum, or as grains up to 150 μm in size. According to powder X-ray diffraction analyses kufahrite is isotypic to its synthetic analogue, it is hexagonal and crystallises in space groupP63/mmcadopting the nickeline structure type. Its unit-cell parameters are:a =4.2492(6) Å;c =5.486(6) Å;V =85.78 Å3andZ =2. The calculated density is 14.80 g/cm–3. The strongest diffraction lines are [d, Å (I, %) (hkl)]: 3.052 (80) (101), 2.197 (100) (102), 2.125 (28) (110), 1.747 (18) (210), 1.528 (35) (202), 1.240 (18) (212) and 0.958 (22) (312). The Vickers hardness is 295 kg/mm2(range 262–320,n= 5), corresponding to a Mohs hardness of 4. The empirical formula of kufahrite, calculated from a mean value of 23 electron-microprobe analyses is (Pt0.94Rh0.04)Σ0.98(Pb0.83Sb0.19)Σ1.02. The name (pronounced as [ku fa rait]) honours Fahrid Shakirovitch Kutyev (1943‒1993), a geologist from the Institute of Volcanology of USSR Academy of Sciences, who played a key role in the discovery of the Koryak–Kamchatka Platinum Belt, including the Ledyanoy Creek placer platinum deposit, where the new mineral has been discovered. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|