KUDRIAVITE, (Cd,Pb)Bi2S4, A NEW MINERAL SPECIES FROM KUDRIAVY VOLCANO, ITURUP ISLAND, KURILE ARC, RUSSIA
Bibliographic record
Abstract
Kudriavite, a new mineral species, occurs as a high-temperature (about 400°C) fumarole incrustation in the steep inner wall of the crater rim of Kudriavy volcano, on Iturup Island, in the Kurile arc, Russia. Associated minerals are cannizzarite, greenockite and pyrite. The mineral occurs as elongate slender platy opaque crystals up to 0.4 × 0.2 × 0.02 mm, usually striated along the elongation. Box-shaped skeletal crystals also are common. The color is dark grey, with a slightly reddish hue and a metallic luster. The streak is black. Crystals of kudriavite have an uneven fracture and are very brittle. Reflectance values for the COM wavelengths [% (R1, R2)] are: 470 nm (36.4, 29.6), 546 nm (38.8, 32.4), 589 nm (38.2, 31.8), and 650 nm (37.7, 31.4). The bireflectance is distinct; the anisotropy is rather strong, but without color effect. Its measured microhardness VHN10 is 129. The electron-microprobe analysis of holotype kudriavite gave Cd 8.25, Pb 13.10, Fe 0.17, Mn 0.26, Bi 55.37, In 2.80, Tl 0.02, S 17.70, Se 2.23, Cl 0.02, sum 99.92 wt.%. The empirical formula, based on seven atoms, is (Cd0.51Pb0.44Fe0.02Mn0.03)∑1.00 (Bi1.83In0.17)∑2.00 (S3.81Se0.19)∑4.00; the idealized formula is (Cd,Pb)Bi2S4. The ideal formula CdBi2S4 requires Cd 17.07, Bi 63.46, S 19.47, for a total of 100.00 wt.%. The strongest nine lines of the X-ray powder-diffraction pattern [ d in A( I )( hkl )] are: 3.715(m)(202), 3.632(m)(204),3.520(s)(112), 3.274(s)(004, 402), 3.169(m)(112), 2.948(s)(311), 2.809(s)(310), 2.346(m)(114, 115), and 1.914(m)(511). The unit-cell parameters of kudriavite, determined on a single crystal, are: a 13.095(1), b 4.0032(3), c 14.711(1) A, β 115.59(1)°, V 695.5(1) A3, Z = 4, space group C 2/ m , Dcalc = 6.578 g/cm3. According to the solution of the structure, kudriavite is the first natural homologue N = 3 of pavonite. The mineral (IMA No. 2003–011) is named after the discovery locality.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 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".