Santabarbaraite from the oxidation zone of the Mednorudyansk field is the first finding in the Urals
| Autor: | N. V. Chukanov, Yu. V. Erokhin, V. S. Ponomarev, I. V. Pekov |
|---|---|
| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Izvestiâ Uralʹskogo Gosudarstvennogo Gornogo Universiteta, Iss 4(48), Pp 36-41 (2017) |
| ISSN: | 2500-2414 2307-2091 |
| DOI: | 10.21440/2307-2091-2017-4-36-41 |
| Popis: | In the oxidation zone of the Mednorudyansk deposit, the authors discovered and studied aqueous ferric oxide phosphate – santabarbaraite. The discovered mineral was in one of the samples of the Mednorudyansk deposit from the collection of N. I. Kozin, collector from Nizhny Tagil. As an independent mineral species, approved by the Commission on New Minerals of the International Mineralogical Association, santabarbaraite was described in 2003 in clays of the lignite sedimentary basin in the mountainous region of Santa Barbara (Italy) and in clays underlying the Pliocene basalts in the southeast of Australia. For Russia, there are few mentions of it; it appears in the deposits of Kerch and Taman iron-ore basins, as well as in bottom sediments and near Lake Baikal. Search of information on the findings of this mineral in literature was unsuccessful, although it is likely that santabarbaraite is not a rare mineral in this region, and acts as the usual product of the oxidation of vivianite in the hypergenesis zone. Santabarbaraite from the Mednorudyansk deposit forms pseudomorphs along the vivianite crystals in cavities among the nodular and cellular limonite. The pseudomorphs of santabarbaraite completely preserved the faceting of lamellar vivianite crystals. Powder X-ray examination of samples of santabarbaraite showed complete absence of diffraction reflexes, which is typical for this mineral. The mineral is characterized by the presence of impurities of magnesium, manganese, zinc, sodium and potassium. The absence in the association of metavivianite and other intermediate mineral phases indicates that the oxidation of vivianite was most likely due to the direct replacement mechanism by santabarbarite. The authors also studied this mineral using thermal analysis, infrared and Raman spectroscopy. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|