Grahampearsonite, Ca2P2O7, a new mineral found in a super-deep diamond from Juína, Brazil

Abstract Grahampearsonite, ideally Ca2P2O7, is a new mineral (IMA 2025-017) that was found in a multi-phase inclusion, in a super-deep diamond (sample RV43) from the Chapadão plateau, Mato Grosso, Brazil. The new mineral is closely associated with tuite, and with other mineral inclusions in the host diamond (that are not in direct contact with grahampearsonite) including larnite, merrillite, apatite, diopside, ilmenite, magnetite, calcite and an unidentified phosphate phase. X-ray diffraction analyses, performed directly on the inclusion, while still entrapped in the diamond, revealed a tetragonal crystal structure (space group P41), with unit-cell parameters a = 6.6966(16) Å, c = 24.145(11) Å, and V = 1082.8(6) Å3. The identification of grahampearsonite as the natural analogue of synthetic β-Ca2P2O7 is strongly supported by micro-Raman, FTIR, crystal chemical, and X-ray diffraction data. The occurrence of grahampearsonite and tuite in a super-deep diamond indicates that grahampearsonite could be related to the decomposition of tuite and may provide new insights into the Earth's deep phosphorus reservoir and the crust-mantle phosphorus cycle. The new mineral honours Dr. Graham Pearson, University of Alberta, for his outstanding contributions on diamond research.

Authors

Institutions

Publication Details

Journal
American Mineralogist
Published
2025-12-03
DOI
https://doi.org/10.2138/am-2025-10072
Primary Topic
Crystal Structures and Properties
Type
article
Field-Weighted Citation Impact
0.00

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Grahampearsonite, Ca2P2O7, a new mineral found in a super-deep diamond from Juína, Brazil

Daniel Grings Cedeño, Eduardo Novais Rodrigues, Lisa Santello, Francesca Innocenzi et al.
American Mineralogist
Crystal Structures and Properties
article

Grahampearsonite, Ca2P2O7, a new mineral found in a super-deep diamond from Juína, Brazil

Daniel Grings Cedeño, Eduardo Novais Rodrigues, Lisa Santello, Francesca Innocenzi, Fabrizio Nestola, Mattia La Fortezza, Tiago Jalowitzki, Fernanda Gervasoni, Andrea Curtolo, Martha G. Pamato, Davide Novella, Yanjuan Wang, Maxwell C. Day, Kai Qu, Reinhardt A. Fuck, Jacopo Nava, Sebastião William da Silva
article en

Abstract

Abstract Grahampearsonite, ideally Ca2P2O7, is a new mineral (IMA 2025-017) that was found in a multi-phase inclusion, in a super-deep diamond (sample RV43) from the Chapadão plateau, Mato Grosso, Brazil. The new mineral is closely associated with tuite, and with other mineral inclusions in the host diamond (that are not in direct contact with grahampearsonite) including larnite, merrillite, apatite, diopside, ilmenite, magnetite, calcite and an unidentified phosphate phase. X-ray diffraction analyses, performed directly on the inclusion, while still entrapped in the diamond, revealed a tetragonal crystal structure (space group P41), with unit-cell parameters a = 6.6966(16) Å, c = 24.145(11) Å, and V = 1082.8(6) Å3. The identification of grahampearsonite as the natural analogue of synthetic β-Ca2P2O7 is strongly supported by micro-Raman, FTIR, crystal chemical, and X-ray diffraction data. The occurrence of grahampearsonite and tuite in a super-deep diamond indicates that grahampearsonite could be related to the decomposition of tuite and may provide new insights into the Earth's deep phosphorus reservoir and the crust-mantle phosphorus cycle. The new mineral honours Dr. Graham Pearson, University of Alberta, for his outstanding contributions on diamond research.

American Mineralogist
Universidade Federal do Rio Grande do Sul (BR), University of Padua (IT), Universidade de Brasília (BR), China Geological Survey (CN), Chinese Academy of Geological Sciences (CN), Instituto de Geociencias (ES), Brazilian Center for Research in Energy and Materials (BR), University of Bayreuth (DE), Nanjing University (CN)
European Commission, Università degli Studi di Padova, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Chinese Academy of Geological Sciences
Openalex Percentile: Top 72%
Crystal Structures and Properties
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.