Pegmatitic Phosphates (PO₄) from Brazil

Researchers involved: Simon Philippo – Kim Totaro

Themes: critical and strategic minerals / environmental mineralogy

This research project aims to study the crystal chemistry of pegmatite phosphates from the MNHNL collections, particularly those from the Cassedanne collection, as well as samples collected directly in the field in Brazil (Rio Grande do Norte and Paraíba) during scientific missions in 2022 and 2025.

Pegmatite phosphates are particularly complex minerals to characterise due to their fine chemistry and the diversity of their crystal structures. Their study requires the use of various analytical techniques, such as polished‑section microscopy, powder X‑ray diffraction, electron microprobe analysis, GemTOF, and crystallographic structural analysis.

Since 2023, this research has been carried out by Kim Totaro, who has undertaken a systematic study of these specimens, both in the laboratory and in the field. After chemical characterisation of the samples in 2024, the 2025 work made it possible to deepen the crystallographic analysis and to complete sampling in collaboration with the Brazilian National Research Fund.

This project continues the work carried out by Maxime Baijot as part of his doctoral thesis, conducted in collaboration with our museum, and contributes to the enhancement of the Cassedanne collection, now preserved at the MNHNL. Through this work, a better understanding of pegmatite crystallisation is sought, while strengthening the scientific quality of our reference collection.

Publications :

* CASSEDANNE J. & PHILIPPO S. (2015) - Minerals and Gems deposits of the eastern Brazilian pegmatites, Volume 1 - Ed. Musée national d’histoire naturelle Luxembourg, p. 1-376 (isbn 978-2-919877-20-1)

* CASSEDANNE J. & PHILIPPO S. (2015) - Minerals and Gems deposits of the eastern Brazilian pegmatites, Volume 2 - Ed. Musée national d’histoire naturelle Luxembourg, p. 377-674 (isbn 978-2-919877-21-8)

* HATERT, F., PHILIPPO, S., OTTOLINI, L., DAL BO, F., SCHOLZ, R., CHAVES, M., YANG, H., DOWNS, R. & MENEZES, L. (2017): Wilancookite, (Ba,K,Na)8(Ba,Li,[])6Be24P24O96·32H2O, a new beryllophosphate with a zeolite framework. European Journal of Mineralogy, 29-5, 923-930.

* BAIJOT M., HATERT F., DAL BO F. & PHILIPPO S. (2014), Mineralogy and petrography of phosphate mineral associations from the Jocão pegmatite, Minas Gerais, Brazil. Canadian Mineralogist Vol. 52, 373-397

* BAIJOT M., HATERT F., DAL BO F. & PHILIPPO S. (2014), Petrographic textures of primary phosphates from pegmatites of the Conselheiro Pena district, Minas Gerais, Brazil: transformation sequence and genetic implications. IMA 2014 – International Mineralogical Association”, Abstract book, 254

* HATERT F. BAIJOT M., PHILIPPO S. & WOUTERS J (2010), "Qingheiite-Fe2+, Na2Fe2+MgAl(PO4)3, a new phosphate from Sebastiao Cristino pegmatite, Minas Gerais, Brazil.“ European Journal Mineralogy 22, 459-467.