Angastonite, CaMgAl₂(PO₄)₂(OH)₄·7H₂O : A new phosphate mineral from Angaston, South Australia
Bibliographic record
Abstract
Angastonite, ideally CaMgAl₂(PO₄)₂(OH)₄·7H₂O, is a newly defined mineral from the Penrice marble quarry, South Australia, Australia. The mineral occurs as snow-white crusts and coatings up to about 1 mm thick associated with minyulite, perhamite, crandallite and apatite-(CaF). The streak is white, the lustre is pearly and the estimated hardness is 2 on the Mohs scale. Angastonite forms platy crystals with the forms {010} (prominent), {101}, {101¯} and {100} (rare), and also occurs as replacements of an unknown pre-existing mineral. There is one cleavage direction on {010} and no twinning has been observed. Angastonite is triclinic, P1¯ , with a = 13.303(1) Å, b = 27.020(2) Å, c = 6.1070(7) Å α = 89.64(1)º, β = 83.44(1)º, γ = 80.444(8)º, V = 2150.5(4) ų, with Z = 6. The mineral is optically biaxial (+), with refractive indices of α = 1.566(2), β = 1.572(2) and γ = 1.584(2) and with 2Vmeas = 70(2)º and 2Vcalc = 71º. Orientation: X˜ a, Y˜ b, Z˜ c; with crystals showing parallel extinction and no axial dispersion. Dmeas is 2.47 g/cm³, whilstD calc is 2.332 g/cm³. The strongest four powder-diffraction lines [d in Å, (I/Io), hkl] are: 13.38, (100), 020; 11.05, (25), 11¯0; 5.73, (23), 101, 230 and 111; 8.01, (21), 130. Angastonite is likely to be related to montgomeryite-group members and have a similar crystal structure, based on slabs of phosphate tetrahedra and Al octahedra.
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.013 | 0.001 |
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".