Grahampearsonite, Ca2P2O7, a new mineral found in a super-deep diamond from Juína, Brazil
Bibliographic record
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 analog 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 honors Graham D. Pearson, University of Alberta, for his outstanding contributions to diamond research.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".