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Gasparite-(La), La(AsO4), a new mineral from Mn ores of the Ushkatyn-III deposit, Central Kazakhstan, and metamorphic rocks of the Wanni glacier, Switzerland
Journal article

Gasparite-(La), La(AsO4), a new mineral from Mn ores of the Ushkatyn-III deposit, Central Kazakhstan, and metamorphic rocks of the Wanni glacier, Switzerland

  • Vereshchagin, Oleg S. Institute of Earth Sciences, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg, Russia. Orcid 0000-0002-4811-2269
  • Britvin, Sergey N. Musée cantonal de géologie, Université de Lausanne, Anthropole, 1015 Lausanne, Switzerland
  • Perova, Elena N. Institute of Earth Sciences, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg, Russia. Orcid 0000-0002-4811-2269
  • Brusnitsyn, Aleksey I. Institute of Earth Sciences, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg, Russia. Orcid 0000-0002-4811-2269
  • Polekhovsky, Yury S. Institute of Earth Sciences, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg, Russia. Orcid 0000-0002-4811-2269
  • Shilovskikh, Vladimir V. Institute of Mineralogy, Urals Branch of the Russian Academy of Sciences, Miass 456317, Russia
  • Bocharov, Vladimir N. Geomodel Centre, St. Petersburg State University, Uliyanovskaya St. 1, 198504 St. Petersburg, Russia
  • van der Burgt, Ate Geertjesweg 39, NL-6706EB Wageningen, The Netherlands
  • Cuchet, Stéphane ch. des Bruyeres 14, CH-1007 Lausanne, Switzerland
  • Meisser, Nicolas Musée cantonal de géologie, Université de Lausanne, Anthropole, 1015 Lausanne, Switzerland
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Published in:
  • American Mineralogist. - Mineralogical Society of America. - 2019, vol. 104, no. 10, p. 1469-1480
Geochemistry and Petrology
Geophysics
English Abstract
Gasparite-(La), La(AsO4), is a new mineral (IMA 2018-079) from Mn ores of the Ushkatyn-III deposit, Central Kazakhstan (type locality) and from alpine fissures in metamorphic rocks of the Wanni glacier, Binn Valley, Switzerland (co-type locality). Gasparite-(La) is named for its dominant lanthanide, according to current nomenclature of rare-earth minerals. The occurrences and parageneses in both localities are distinct: minute isometric grains up to 15 μm in size, associated with friedelite, jacobsite, pennantite, manganhumite series minerals (alleghanyite, sonolite), sarkinite, tilasite, and retzian-(La) are typically embedded into calcite-rhodochrosite veinlets (Ushkatyn-III deposit) vs. elongated crystals up to 2 mm in size in classical alpine fissures in two-mica gneiss without indicative associated minerals (Wanni glacier). Their chemical compositions have been studied by EDX and WDX; crystal-chemical formulas of gasparite-(La) from the Ushkatyn-III deposit (holotype specimen) and Wanni glacier (co-type specimen) are (La0.65Ce0.17Nd0.07Ca0.06Mn0.05Pr0.02)1.02[(As0.70V0.28P0.02)1.00O4] and (La0.59Ce0.37Nd0.02 Ca0.02Th0.01)1.01[(As0.81P0.16Si0.02S0.02)1.01O4], respectively. In polished sections, crystals are yellow and translucent with bright submetallic luster. Selected reflectance values R1/R2 (λ, nm) for the holotype specimen in air are: 11.19/9.05 (400), 11.45/9.44 (500), 10.85/8.81 (600), 11.23/9.08 (700). The structural characteristics of gasparite-(La) were studied by means of EBSD (holotype specimen), XRD, and SREF (co-type specimen). Gasparite-(La) has a monoclinic structure with the space group P21/n. Our studies revealed that gasparite-(La) from the Ushkatyn-III deposit and Wanni glacier have different origins. La/Ce and As/P/V ratios in gasparite-(La) may be used as an indicator of formation conditions.
Language
  • English
Open access status
closed
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Persistent URL
https://sonar.ch/global/documents/46372
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