Wiklundite, ideally Pb<sub>2</sub><sup>[4]</sup>(Mn<sup>2+</sup>,Zn)<sub>3</sub>(Fe<sup>3+</sup>,Mn<sup>2+</sup>)<sub>2</sub>(Mn<sup>2+</sup>,Mg)<sub>19</sub>(As<sup>3+</sup>O<sub>3</sub>)<sub>2</sub>[(Si,As<sup>5+</sup>)O<sub>4</sub>]<sub>6</sub>(OH)<sub>18</sub>Cl<sub>6</sub>, a new mineral from Långban, Filipstad, Värmland, Sweden: Description and crystal structure
Bibliographic record
Abstract
Abstract Wiklundite, ideally Pb 2 [4] (Mn 2+ ,Zn) 3 (Fe 3+ ,Mn 2+ ) 2 (Mn 2+ ,Mg) 19 (As 3+ O 3 ) 2 [(Si,As 5+ )O 4 ] 6 (OH) 18 Cl 6 , isa new arseno-silicate mineral from Långban, Filipstad, Värmland, Sweden. Both the mineral and the name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2015-057). Wiklundite and a disordered wiklundite-like mineral form radiating, sheaf-like aggregates (up to 1 mm long) of thin brownish-red and slightly bent lath-shaped crystals. It occurs in a dolomite-rich skarn in association with tephroite, mimetite, turneaurite, johnbaumite, jacobsite, barite, native lead, filipstadite andparwelite. Wiklundite is reddish brown to dark brown, and the streak is pale yellowish brown. The lustre is resinous to sub-metallic, almost somewhat bronzy, and wiklundite does not fluoresce under ultraviolet light. The calculated density is 4.072 g cm –3 . Wiklundite is brittle with an irregular fracture, and has perfect cleavage on {001}; no parting or twinning was observed. Wiklundite is uniaxial (–), orange red and non-pleochroic in transmitted light, but shows incomplete extinction and distorted interference figures, preventing complete determination of optical properties. Electron-microprobe analysis (H 2 O calculated from the structure) of wiklundite gave SiO 2 11.17, Al 2 O 3 0.06, Fe 2 O 3 4.46, As 2 O 5 0.75, As 2 O 3 6.81, MnO 47.89, ZnO 0.78,CaO 0.09, PbO 14.48, Cl 6.65, H 2 O 5.18, O=Cl 2 –1.50, total 97.11 wt.%, As valences and H2O content taken from the crystal-structure refinement, and Fe 3+ /(Fe 2+ + Fe 3+ ) determined by Mössbauer spectroscopy. Wiklundite is hexagonal-rhombohedral, space group R 3 c , a = 8.257(2), c = 126.59(4) Å, V = 7474(6) Å3, Z = 6. The crystal structure of wiklundite was solved by direct methods and refined to a final R 1 index of 3.2%. The structure consists of a stacking of five layers of polyhedra: three layers consist of trimers of edge-sharing Mn 2+ -dominant octahedra linked by (SiO 4 ) tetrahedra, (Fe 3+ (OH) 6 ) dominant octahedra and (AsO 3 ) triangular pyramids; one layerof corner-sharing (SiO 4 ) and (Mn 2+ O 4 ) tetrahedra; and one layer of (Mn 2+ Cl 6 ) octahedra and (Pb 2+ (OH) 3 Cl 6 ) polyhedra. The mineral is named after Markus Wiklund ( b . 1969) and Stefan Wiklund ( b . 1972), the well-known Swedish mineral collectors who jointly found the specimen containing the mineral.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.021 | 0.008 |
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 source (direct Gemma or distilled Codex), 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".