Diaspores and related hydroxides: Spectral‐compositional properties and implications for Mars
Bibliographic record
Abstract
Differences in spectral reflectance properties (0.3–26 μm) of a suite of metal hydroxides (gibbsite, böhmite, diaspore, goethite, and manganite) have been found to be a function of both structural and compositional differences between these minerals. The properties of the O‐H stretching fundamental bands in particular can be used to identify the presence of these minerals and to discriminate isostructural and heteromorphous species. This is due to the fact that the O‐H stretching fundamental bands are very intense in these minerals and occur at longer wavelengths than those of other minerals, and also due to the fact that these metal hydroxides lack strong absorption bands at shorter wavelengths. In the case of dimorphous minerals such as böhmite (γ‐AlO(OH)) and diaspore (α‐AlO(OH)), differences in the wavelength positions of O‐H stretching fundamental bands can be of the order of 0.1–0.3 μm. Reflectance spectra of metal hydroxide‐bearing “ores” (bauxites) and impure samples indicate that accessory phases, in particular iron‐bearing minerals, have a more pronounced effect on spectral reflectance toward shorter wavelengths. Intimate mixtures of diaspore + orthopyroxene indicate that diaspore abundances as low as 5 wt% (or less) can be detected by the appearance of characteristic absorption bands at 3.33 and 3.41 μm. This finding has particular relevance to the study of near‐infrared spectra of Mars, in that the conditions which favor diaspore formation on the Earth may have also been prevalent early in Mars' history. If diaspore did form on Mars in the past, it is likely to have persisted to the present.
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.
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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.
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".