MARTINITE, A NEW HYDRATED SODIUM CALCIUM FLUORBOROSILICATE SPECIES FROM MONT SAINT-HILAIRE, QUEBEC: DESCRIPTION, STRUCTURE DETERMINATION AND GENETIC IMPLICATIONS
Bibliographic record
Abstract
Martinite, ideally (Na,□,Ca) 12 Ca 4 (Si,S,B) 14 B 2 O 38 (OH,Cl) 2 F 2 ·4H 2 O, is a new mineral species from the Poudrette quarry, Mont Saint-Hilaire, Quebec. The mineral arose through the interaction of highly fractionated, hyperagpaitic fluids with sodalite syenite xenoliths. Martinite develops both as single crystals and as rosettes of triangular to roughly hexagonal plates varying from 50 μm to a maximum of about 1 mm across. Individual crystals are typically 2− x S minerals (UK55 group), UK53a, UK73, UK82, UK91 and a lollingite-like mineral. The mineral has a vitreous luster, is transparent, has a white streak and shows no fluorescence in either short- or long-wave ultraviolet radiation. It has a Mohs hardness of 4; the crystals are inelastic, and have a perfect cleavage on {001}. It is brittle with an uneven fracture. The calculated density is 2.51 g/cm 3 . Martinite is non-pleochroic, optically biaxial (−), with α 1.529(1), β 1.549(1), γ1.551(1) (for λ = 590 nm), 2 V meas = 38(1)°, 2 V calc = 35(1)°; no dispersion was noted. The optical orientation is X ≈ c . On average, 19 electron-microprobe analyses gave: Na 2 O 17.70, MgO 0.03, CaO 16.71, MnO 0.07, B 2 O 3 (calc.) 5.02, SiO 2 48.85, TiO 2 0.06, SO 3 2.30, F 2.18, Cl 1.09 and H 2 O (calc.) 4.44, O=F+Cl −1.17, total 97.28 wt.%. The empirical formula (based on 46 anions) is: (Na 9.19 □ 1.99 Ca 0.82 ) ∑12 (Ca 3.97 Mn 0.02 Mg 0.01 ) ∑4 (Si 13.08 S 0.46 B 0.45 Ti 0.01 ) ∑14.00 B 2 O 38 (OH 1.50 Cl 0.50 ) ∑2.00 (F 1.84 OH 0.16 ) ∑2 ·4H 2 O. The principal absorption bands in the infrared spectrum include 3437, 1634 and 1011 cm −1 (shoulders at 1137, 1081, 898 and 862 cm −1 ) and five bands in the region 786–498 cm −1 . The mineral is triclinic, space group P 1, a 9.5437(7), b 9.5349(6), c 14.0268(10) A, α 108.943(1), β 74.154(1), γ119.780(1)°, V 1038.1(1) A 3 , Z = 2. The strongest seven lines in the X-ray powder-diffraction pattern [ d in A( I )( hkl )] are: 13.18(100)(001), 6.58(43)(002), 2.968(37)(130), 3.29(34)(004,220), 2.908(27)(323), 3.02(17)(211), 2.800(17)(212). The structure of martinite has been refined to R = 6.30, wR 2 = 13.82%. The mineral is strongly layered, with sheets of tetrahedra ( T ), octahedra ( O ) and interlayer cations ( X ). The T layers are composed of six-membered rings of SiO 4 tetrahedra linked by [(Si,B)]O 4 and (BO 4 ) tetrahedra. The sheets of octahedra are composed of edge-sharing M ϕ 6 octahedra ( M : Na,Ca; ϕ: unspecified ligand) arranged in a closest-packed arrangement. The O sheets are effectively sandwiched between two symmetrically equivalent T layers ( T 2 , & T macr; 2 ), producing a strongly bonded T – O – T unit. The interlayer component ( X ) houses poorly ordered Na polyhedra and H 2 O molecules. Stacking of these principal components perpendicular to [001] results in a OT 2 X & T macr; 2 O module. Martinite is a member of the reyerite–gyrolite group. It represents the first B-bearing mineral of the group and the first mineral known to possess the OT 2 X & T macr; 2 O module. The name honors Robert Francois Martin (b. 1941), Professor of Geology at McGill University and long-time editor of The Canadian Mineralogist .
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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 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".