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

Détails

ID Serval
serval:BIB_4A461E0846F2
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
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
Périodique
American Mineralogist
Auteur⸱e⸱s
Vereshchagin Oleg S., Britvin Sergey N., Perova Elena N., Brusnitsyn Aleksey I., Polekhovsky Yury S., Shilovskikh Vladimir V., Bocharov Vladimir N., van der Burgt Ate, Cuchet Stéphane, Meisser Nicolas
ISSN
0003-004X
1945-3027
Statut éditorial
Publié
Date de publication
2019
Peer-reviewed
Oui
Volume
104
Pages
1469-1480
Langue
anglais
Résumé
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.
Mots-clé
Gasparite-(La), new mineral, arsenate, REE, Mn ores, monazite-type structure, Ushkatyn-III, Kazakhstan, Wanni glacier, Binn Valley, Switzerland
Web of science
Création de la notice
18/03/2021 13:34
Dernière modification de la notice
19/03/2021 6:26
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