Articles | Volume 38, issue 3
https://doi.org/10.5194/ejm-38-353-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/ejm-38-353-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Dehydration reactions in guano-derived minerals: the taranakite-to-francoanellite transformation
Department of Earth, Environmental and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
Nicola Campomenosi
Department of Earth, Environmental and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
Fabio Bellatreccia
Department of Science, University Roma Tre, Rome, Italy
Donato Belmonte
Department of Earth, Environmental and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
Jo De Waele
Department of Biological, Geological and Environmental Sciences, Alma Mater University of Bologna, Bologna, Italy
Cristina Carbone
Department of Earth, Environmental and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
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Cristian Biagioni, Jiří Sejkora, Natale Perchiazzi, Enrico Mugnaioli, Daniela Mauro, Donato Belmonte, Radek Škoda, and Zdeněk Dolníček
Eur. J. Mineral., 37, 733–746, https://doi.org/10.5194/ejm-37-733-2025, https://doi.org/10.5194/ejm-37-733-2025, 2025
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Marioantofilliite, ideally [Cu4Al2(OH)12](CO3)•3H2O, is a new member of the hydrotalcite supergroup occurring as a supergene mineral in the Cu–Fe deposit of Monte Copello–Reppia (Liguria, Italy). Its name honours Mario Antofilli (1920–1983) for his contribution to the knowledge of the mineralogy of Liguria. Its discovery and description improve the knowledge of layered double hydroxides (LD), with implications for the group of Cu–Al LDH actively studied for its technological properties.
Giuseppe Illuminati, Silvia Musetti, Fabio Bellatreccia, Cristian Biagioni, Enrico Caprilli, Ahmad Rabiee, and Marco E. Ciriotti
Eur. J. Mineral., 37, 483–504, https://doi.org/10.5194/ejm-37-483-2025, https://doi.org/10.5194/ejm-37-483-2025, 2025
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In this work, we present the most iron-rich chrysoberyl discovered to date, found in the Sabatini Volcanic Complex (Latium, Italy). We provide a comprehensive overview of its chemical, structural, spectroscopic, and optical properties. The characterization of this chrysoberyl reveals several unique features, offering valuable insights into its genetic model and geochemical constraints, which are consistent with existing literature on the Sabatini complex and with ongoing research.
Cristian Biagioni, Enrico Mugnaioli, Sofia Lorenzon, Daniela Mauro, Silvia Musetti, Jiří Sejkora, Donato Belmonte, Nicola Demitri, and Zdeněk Dolníček
Eur. J. Mineral., 36, 1011–1022, https://doi.org/10.5194/ejm-36-1011-2024, https://doi.org/10.5194/ejm-36-1011-2024, 2024
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Nannoniite, Al2(OH)5F, is a new mineral species discovered in the Cetine di Cotorniano mine (Tuscany, Italy). Its description was possible through a multi-technique approach, and its crystal structure was solved through three-dimensional electron diffraction, revealing close relations with gibbsite. The partial replacement of (OH) by F induces subtle by detectable structural changes. This study reveals that Al hydroxides could be a source of F in geological environments.
Donato Belmonte, Mattia La Fortezza, and Francesca Menescardi
Eur. J. Mineral., 34, 167–182, https://doi.org/10.5194/ejm-34-167-2022, https://doi.org/10.5194/ejm-34-167-2022, 2022
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We carried out theoretical calculations of the vibrational and thermophysical properties of Mg2SiO4 ringwoodite, a major mineral phase of the Earth's mantle transition zone. We tried to understand why current data on volume thermal expansion are still controversial by performing a detailed analysis of vibrational spectra. We proposed a reliable parametrization for thermal expansivity of ringwoodite in the transition zone which could be useful for numerical simulations of mantle convection.
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Short summary
Deposits of bat guano in cave environments host diverse assemblages of secondary minerals, which can go through partial dehydration processes in response to varying environmental conditions. In this article, we investigate the thermodynamics and kinetics which lead guano-derived taranakite to lose part of its structural water and transform into francoanellite. Our results allow us to present evidence-based hypotheses to explain the occurrence of the latter in natural environments.
Deposits of bat guano in cave environments host diverse assemblages of secondary minerals, which...