Extending the mineralogy of U6+ (I.): Crystal structure of lepersonnite-(Gd) and a description of the new mineral lepersonnite-(Nd)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F25%3A10136999" target="_blank" >RIV/00023272:_____/25:10136999 - isvavai.cz</a>

Alternative codes found

RIV/68378271:_____/25:00642223 RIV/00216224:14310/25:00143316

Result on the web

<a href="https://www.cambridge.org/core/journals/mineralogical-magazine/article/abs/extending-the-mineralogy-of-u6-i-crystal-structure-of-lepersonnitegd-and-a-description-of-the-new-mineral-lepersonnitend/23DFEF8934AB52E4A45A938CA2C85688" target="_blank" >https://www.cambridge.org/core/journals/mineralogical-magazine/article/abs/extending-the-mineralogy-of-u6-i-crystal-structure-of-lepersonnitegd-and-a-description-of-the-new-mineral-lepersonnitend/23DFEF8934AB52E4A45A938CA2C85688</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1180/mgm.2025.29" target="_blank" >10.1180/mgm.2025.29</a>

Result language

angličtina

Original language name

Extending the mineralogy of U6+ (I.): Crystal structure of lepersonnite-(Gd) and a description of the new mineral lepersonnite-(Nd)

Original language description

Two uranyl carbonate silicate minerals have been studied in detail, lepersonnite-(Gd) and the new mineral lepersonnite-(Nd). Both minerals originate from Katanga province in the Democratic Republic of Congo (Africa): lepersonnite-(Gd) from the Shinkolobwe mine (type locality) and lepersonnite-(Nd) from the Swambo mine (type locality) and Shinkolobwe mine. Each occurs as radial to acicular aggregates composed of long prismatic, thin crystals, as the products of hydration-oxidation weathering of uraninite. A detailed description of the chemical and physical properties of lepersonnite-(Nd) is provided, including the thermal analysis of the -(Gd) member. The crystal structure of lepersonnite-(Gd) has been solved based on 3D electron diffraction data. According to the best dataset at 95 K, lepersonnite-(Gd) is orthorhombic, with a = 11.838(134) Å, b = 15.822(333) Å, c = 39.147(190) Å and V = 7353(282) Å3 (Z = 4). The dynamic refinement of the crystal structure (Robs/wRobs = 0.1204/0.1088 and Rall/wRall = 0.1204/0.1088 for 3090/50507 observed/all reflections and 247 refined parameters) revealed a large complex sheet structure with structural units defining a new lepersonnite topology. It contains infinite sheets of uranyl polyhedra, planar CO3 groups, protonated Si-tetrahedra, and Gd3+ polyhedra, and a thick interlayer hosted with H2O and partially occupied Ca2+ sites. Based on the structure refinement, bond-valence considerations, and new electron microprobe data, we infer that the ideal formula of lepersonnite-(Gd) is [Ca0.5Gd0.5(H2O)18(OH)1.5] [Gd(UO2)12(SiO3OH)2(CO3)4(OH)10O2(H2O)5]. On the basis of their closely related powder X-ray diffraction patterns and the similar behaviour of Nd and Gd, we expect the two minerals to adopt the same structures, apart from Ca, which was absent in lepersonnite-(Nd). The ideal formula for lepersonnite-(Nd) is [Nd(H2O)18(OH)2][Nd(UO2)12(SiO3OH)2(CO3)4(OH)10O2(H2O)5].

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10504 - Mineralogy

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Mineralogical Magazine

ISSN

0026-461X

e-ISSN

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Volume of the periodical

89

Issue of the periodical within the volume

5

Country of publishing house

GB - UNITED KINGDOM

Number of pages

17

Pages from-to

549-565

UT code for WoS article

001584812100001

EID of the result in the Scopus database

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