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Record W4292354326 · doi:10.3749/canmin.2200001

Bortolanite, Ca2(Ca1.5Zr0.5)Na(NaCa)Ti(Si2O7)2(FO)F2, a New Rinkite-Group (Seidozerite Supergroup) TS-Block Mineral from the Bortolan Quarry, Poços de Caldas Massif, Minas Gerais, Brazil

2022· article· en· W4292354326 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
venuePublished in a venue whose home country is Canada.

Bibliographic record

VenueThe Canadian Mineralogist · 2022
Typearticle
Languageen
FieldMaterials Science
TopicCrystal Structures and Properties
Canadian institutionsUniversity of Manitoba
Fundersnot available
KeywordsNephelineCrystallographyStructural formulaMohs scale of mineral hardnessAegirineTriclinic crystal systemSupergroupElectron microprobeMineralChemistryMineralogyAlbiteMaterials scienceCrystal structureGeologyGeochemistryQuartzMetallurgy

Abstract

fetched live from OpenAlex

ABSTRACT Bortolanite (IMA 2021–040a), ideally Ca2(Ca1.5Zr0.5)Na(NaCa)Ti(Si2O7)2(FO)F2, is a rinkite-group (seidozerite supergroup) TS-block mineral from Poços de Caldas massif, Minas Gerais, Brazil. Associated minerals are götzenite, nepheline, alkali feldspar, aegirine, natrolite, analcime, and manganoan pectolite. Bortolanite shows complex compositional zoning with götzenite and is visually indistinguishable from götzenite. Bortolanite is pale-yellow to brown and has a vitreous luster. Cleavage is perfect parallel to {100}. Mohs hardness is 5. Bortolanite fluoresces weak yellow under ultraviolet light (100–280 nm). Dcalc. = 3.195 g/cm3. Bortolanite is biaxial (+) with refractive indices (λ = 589.3 nm) α = 1.673(2), β = 1.677(2), γ = 1.690(2); 2Vmeas. = 56(2)°, 2Vcalc. = 58.4°. Chemical analysis by electron microprobe gave Nb2O5 1.07, HfO2 0.20, ZrO2 6.70, TiO2 9.94, SiO2 32.49, Gd2O3 0.12, Nd2O3 0.37, Ce2O3 1.25, La2O3 0.65, Y2O3 0.31, FeO 0.59, MnO 1.46, CaO 31.15, Na2O 8.36, F 6.95, O=F –2.93, sum 98.68 wt.%. The empirical formula based on 18 (O + F) apfu is (Ca1.88La0.03Ce0.06Nd0.02Gd0.01)Σ2[Ca1.56(Zr0.41Hf0.01Y0.02)Σ0.44]Σ2(Na0.85Ca0.15)Σ1(Na1.18Ca0.60Mn0.16Fe2+0.06)Σ2(Ti0.94Nb0.06)Σ1(Si4.07O14)(O1.24F0.76)Σ2F2, Z = 1. The simplified formula is Ca2(Ca,Zr)2Na(Na,Ca)2Ti(Si2O7)2(O,F)2F2. Bortolanite is triclinic, space group P, a 9.615(3), b 5.725(2), c 7.316(2) Å, α 89.91(1), β 101.14(1), γ 100.91(1)°, V 387.7(3) Å3. The crystal structure was refined to R1 = 3.19% on the basis of 2194 unique reflections [F > 4σ(F)] measured using a Bruker APEX II ULTRA three-circle diffractometer with a rotating-anode generator (MoKα), multilayer optics, and an APEX II 4K CCD detector. The crystal structure of bortolanite is a framework of TS (Titanium-Silicate) blocks [structure type B3(RG)], where the TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage and stereochemistry typical for the rinkite group where Ti (+ Nb + Zr) = 1 apfu. The O sheet is composed of Ti-dominant MO(1) octahedra, [8]Na-dominant MO(2) polyhedra and (Na,Ca) MO(3) octahedra. In the H sheet in bortolanite, Si2O7 groups link to (Ca1.5Zr0.5) MH and Ca-dominant AP octahedra. Along a, TS blocks link directly through common edges of MH and AP polyhedra and common vertices of MH, AP, and Si polyhedra of the H sheets belonging to two TS blocks. The name bortolanite is after the locality: the Bortolan quarry in the Poços de Caldas massif, Brazil. Bortolanite is isostructural with three rinkite-group minerals: fogoite-(Y), hainite-(Y), and götzenite.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Science and technology studies, Insufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: Not applicable
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.414
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.001
Science and technology studies0.0030.001
Scholarly communication0.0010.000
Open science0.0020.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0040.000

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.

Opus teacher head0.016
GPT teacher head0.225
Teacher spread0.210 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it