The spectroscopy of luminescent geological materials
Bibliographic record
Abstract
Luminescence is the non-incandescent emission of light from materials excited by an electron beam. Electron irradiation raises sample electrons to an excited state, which then emit a photon as they return to a lower energy. Luminescence phenemona may be studied in several ways, including spectral and spatial methods. Whilst cathodolominescence (CL) has become an established method of analysis for Earth materials, other forms of luminescence in minerals should not be overlooked. Photoluminescence (PL) studies, for example, allow for emission and excitation spectroscopy to be examined in weak- to strongly luminescent minerals, such as wilmenite. In the case of quartz PL, emission spectroscopy investigations have shown that excitation at different wavelengths produces highly variable emission spectra that relate to one or more transitions for excitation. As the building blocks to rocks, minerals and the atoms or ions within preserve critical information concerning the conditions attending growth or subsequent evolution - thus, investigation of these can inform on the origin or surface/near surface interactions relating to environmental change. As a non-destructive technique used in the study of rare materials (e.g., Lunar meteorites) luminescence imaging and spectroscopy have the potential to help characterise, as well as, elucidate domains or reveal fine-scale features not resolvable by optical methods. Advances in instrumentation now permit the collection of multi-dimensional data sets (e.g., hyperspectral) that can be interrogated off-line. The simultaneous capture and interpretation of compositional and luminescence signals has the potential to greatly improve our understanding of causes of luminescence, be these trace activator or defect.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.003 |
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".