hibonite

Composition compatible with hibonite

Record an analytical test of the proposed identity without forcing imperfect data into the ideal formula.

1. Does the analysed domain support CaAl12O19-based chemistry after accounting for measured substitutions? definition
2. What analytical totals, uncertainties, normalization assumptions, and detection limits accompany that assignment? measurement

Diffraction-supported phase

Require a traceable reference comparison and explicit treatment of ambiguous or overlapping signals.

1. Which measured reflections or structural refinement support the hibonite assignment? measurement
2. Which alternative calcium aluminate or associated mineral phases remain compatible with the data? boundary

Substitution evidence

Track how a proposed substitution mechanism is supported and what assumptions it requires.

1. Which Ti, Mg, Fe, rare-earth, or other constituents were actually measured within hibonite? measurement
2. Which valences and site occupancies were measured directly, and which were inferred from charge balance or a structural model? provenance

Resolved analysis domain

Locate each analysis relative to grain boundaries, inclusions, and compositional domains.

1. How does analytical spot size compare with hibonite grain size, zoning width, and nearby inclusions? measurement
2. Does the variation persist within resolved hibonite, or can adjacent phases explain it? boundary

Usable grain domain

Identify intact material suitable for the intended analysis.

1. What are the hibonite grain dimensions, orientation, and distributions of cracks or cleavage surfaces? measurement
2. Which domain can be sampled or polished while preserving the texture needed for interpretation? action

Condition-specific properties

Keep measured specimen properties distinct from reference values and application targets.

1. Which density, hardness, optical, or thermal properties were measured on this material, under what conditions? measurement
2. What heating, grinding, mounting, or chemical treatment preceded the observations? provenance
3. After treatment, what evidence confirms that the examined domain remains hibonite? measurement

Traceable hibonite context

Record host relationships and distinguish documented origin from attribution.

1. Which locality, meteorite accession, inclusion identifier, or synthesis batch anchors this grain's provenance? provenance
2. Which contacts, inclusions, rims, or associated phases were observed around the hibonite? measurement
3. Is the stated origin documented, inferred, or unknown? provenance

Qualified redox and isotope inference

Titanium valence alone does not uniquely determine oxygen fugacity; composition and site occupancy affect interpretation. [Experimental study](https://eprints.whiterose.ac.uk/id/eprint/114587/1/hibonite_accepted_version.pdf)

1. What independent constraints and composition-matched standards support a proposed redox interpretation? boundary
2. If isotopic origin or age is claimed, which measurements, corrections, standards, and assumptions support it? provenance
3. Which proposed formation claims should remain unresolved until additional evidence is obtained? action

Fit for stated purpose

Make acceptance depend on measured phase abundance, chemistry, geometry, and tolerable consumption.

1. What hibonite purity, substitution limits, grain dimensions, or homogeneity does the intended task require? action
2. Which measurements demonstrate compliance, and how much material would further verification consume? measurement

Documented material controls

Base controls on physical form, measured constituents, host material, and applicable documentation rather than the mineral name alone.

1. Will preparation generate dust or expose inclusions, coatings, or host constituents requiring specific controls? action
2. Which verified identifiers and safety records apply to this composition and supplied form? boundary
3. What specimen evidence, including radiological measurements where warranted by provenance, supports the handling decision? measurement

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of hibonite this model covers, and on what evidence? provenance

Identifiers and schemes

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these identifiers and schemes hold for the sense of hibonite this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of hibonite this model covers, and on what evidence? provenance

Typical measurements

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these typical measurements hold for the sense of hibonite this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of hibonite this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of hibonite this model covers, and on what evidence? provenance