Raygrantite, Pb<sub>10</sub>Zn(SO<sub>4</sub>)<sub>6</sub>(SiO<sub>4</sub>)<sub>2</sub>(OH)<sub>2</sub>, A New Mineral Isostructural With Iranite, From the Big Horn Mountains, Maricopa County, Arizona, Usa
Bibliographic record
Abstract
Abstract A new mineral species, raygrantite, ideally Pb 10 Zn(SO 4 ) 6 (SiO 4 ) 2 (OH) 2 , has been found in the Big Horn Mountains, Maricopa County, Arizona, USA. Associated minerals are galena, anglesite, cerussite, lanarkite, leadhillite, mattheddleite, alamosite, hydrocerussite, caledonite, and diaboleite. Raygrantite crystals are bladed with striations parallel to the elongated direction (the c axis). Twinning (fish-tail type) is pervasive on (1 2 ). The mineral is colorless, transparent with white streak, and has a vitreous luster. It is brittle and has a Mohs hardness of ∼3; cleavage is good on {120} and no parting was observed. The calculated density is 6.374 g/cm 3 . Optically, raygrantite is biaxial (+), with n α = 1.915(7), n β = 1.981(7), n γ = 2.068(9), 2V meas = 76(2)°, and 2V calc = 85°. It is insoluble in water, acetone, or hydrochloric acid. An electron microprobe analysis yielded the empirical formula Pb 2+ 9.81 Zn 2+ 0.93 (S 1.00 O 4 ) 6 (Si 1.05 O 4 ) 2 (OH) 2 . Raygrantite is a new member of the iranite mineral group. It is triclinic, with space group P and unit-cell parameters a 9.3175(4), b 11.1973(5), c 10.8318(5) A, α 120.374(2), β 90.511(2), γ 56.471(2)°, and V 753.13(6) A 3 . Its crystal structure, refined to R 1 = 0.031, is characterized by slabs that lie parallel to (120) of SO 4 and SiO 4 tetrahedra with ZnO 4 (OH) 2 octahedra, held together by Pb 2+ cations displaying a wide range of Pb–O bond distances. The discovery of raygrantite indicates that, in addition to complete OH–F and Cu–Zn substitutions, there is also a complete substitution between (CrO 4 ) 2– and (SO 4 ) 2– in the iranite group of minerals, pointing to the possible existence of a number of other (SO 4 ) 2– -bearing iranite-type phases yet to be found or synthesized.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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".