A CRYSTALLOGRAPHIC STUDY OF THE INCOMPLETE SOLID-SOLUTION BETWEEN PLUMBOJAROSITE AND JAROSITE
Bibliographic record
Abstract
An incomplete solid-solution series exists between jarosite, KFe 3 (SO 4 ) 2 (OH) 6 , and plumbojarosite, Pb[Fe 3 (SO 4 ) 2 (OH) 6 ] 2 , on the basis of experimental data and the observed chemical variations of these minerals in nature. Samples were synthesized in a chloride-rich solution at 140° and 110°C and studied using X-ray powder diffraction, Rietveld analysis and chemical analysis. Under these conditions, plumbojarosite will only precipitate if the solution has a high concentration of Pb, 99 mol.% Pb. Only jarosite forms from solutions with up to 79 mol.% Pb in the starting solution. At 85 mol.% Pb in the solution, both jarosite and plumbojarosite precipitate. At the conditions of synthesis, Pb substitution into jarosite is extremely limited, with occupancy of 2% in the potassium site. Increased Pb in the starting solution resulted in no increased substitution of Pb into jarosite, but an increased substitution of H 3 O + into the structure. An increase in charge due to Pb 2+ substitution at the A site causes a charge imbalance in the structure. Potassium substitution into plumbojarosite is more extensive, K/(Pb + K) = 32%. Potassium substitution preferentially occurs in one of the two symmetrically distinct A -sites, based on a Rietveld refinement of site populations.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 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".