---
slug: the-colour-of-gold
passed: 2026-10-14
by: the assay line (research/assay-line/queue-1014c/), Codex fixer directed by claude-assaying-boyle-1014; source record by Codex, checked by Codex
checked: 90
confirmed: 79
wrong: 11
unverifiable: 0
observed: 0
stale: 0
---

This was the directed repair pass for the 11 items in research/assay-line/queue-1014c/the-colour-of-gold/triage.json, against the layer read at c8289bd340. The fixer re-read each item's evidence before editing and retained the 79 CONFIRMED checks from the Codex source/checker record, with their source URLs, entry identifiers and qualifications; those retained checks are attributed to N2, not represented as 79 new external investigations. There are eight WRONG item lines covering seven distinct errors, and three MINOR lines, counted in wrong as the gate permits. X4 and X10 share one correction. Seven corrections are dated 2026-10-14 in HTML and markdown; the MINOR fixes have no page correction. The requested assay date is retained across the local date rollover.

## Claims

- WRONG | the one metal a child can pick out of a tray by colour alone. | https://www.nature.com/articles/s41524-019-0266-0 | [X1; child-colour] Re-read for this fix: Prandini, Introduction, identifies both gold and copper as coloured elemental metals. The exclusivity is false; this pass does not claim a child-recognition experiment.
- MINOR | it was not properly written down for chemists until the late 1970s. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://orbit.dtu.dk/en/publications/relativistic-band-calculation-and-the-optical-properties-of-gold/; https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [X2; late-1970s] Re-read for this fix: Pyykkö and Desclaux p. 279 and reference 32c review the 1971 Christensen and Seraphin calculation; DTU dates it 1971. These support a 1979 review, without establishing first accessibility to chemists.
- WRONG | feels a nucleus the contracted core now screens less completely. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [X3; core-screening] Re-read for this fix: Pyykkö and Desclaux p. 277, Effects 1 and 3, says contracted s/p orbitals increase screening and d/f orbitals expand. P. 278 explicitly identifies Au 6s contraction as direct.
- WRONG | Turn off the chapter of physics published in 1905 and gold turns the colour of every other metal. | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf; https://www.nature.com/articles/s41524-019-0266-0 | [X4; einstein-1905] Re-read for this fix: Prandini, Introduction, names copper as another coloured elemental metal. The silver-white counterfactual for gold does not make every other metal silver-white. Same error as X10.
- MINOR | about as weakly as atoms in a frozen gas | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [X5; frozen-gas] Re-read for this fix: Calvo pp. 7583-7584 distinguishes small-cluster van der Waals behaviour from bulk metallic bonding and requires many-body interactions. It supplies no bulk-Hg/frozen-gas cohesion equality.
- WRONG | that 2.4 eV really is blue light | https://geo.libretexts.org/Courses/De_Anza_College/An_Introduction_to_Weather_and_Climate/11%3A_Atmospheric_Optics/11.01%3A_Visible_Light_and_Scattering; https://web.uvic.ca/~mcindoe/424/relativity.pdf | [X6; blue-2-4] Re-read for this fix: 1239.841984 / 2.4 = 516.600827 nm. The De Anza table gives green as 495-570 nm and blue as 450-495 nm; the page mapping at the unrounded edge gives [39,255,0]. Pyykkö p. 279 supports stronger blue/violet absorption.
- WRONG | Now nothing in the visible band is absorbed, gold reflects all of it, and it would look white-grey like silver. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf; https://www.nature.com/articles/s41524-019-0266-0 | [X7; off-visible] Re-read for this fix: Romaniello and de Boeij Eq. (2), p. 164303-2, separates interband and intraband response; p. 164303-5 describes absorption from carrier scattering. Moving the strong interband edge does not establish zero absorption.
- WRONG | is what the 1979 calculations established was the non-relativistic answer. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://orbit.dtu.dk/en/publications/relativistic-band-calculation-and-the-optical-properties-of-gold/ | [X8; 1979-counterfactual] Re-read for this fix: Pyykkö and Desclaux p. 279 and reference 32c credit Christensen and Seraphin, Physical Review B 4, 3321 (1971). The DTU publication record confirms 1971; 1979 dates the review.
- WRONG | dropping its melting point ~105 K below room temperature: liquid only because of Einstein. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [X9; dek-105-below] Re-read for this fix: Calvo p. 7584 gives 355 K without relativity and 250 K with it: 105 K lower. Against the page's 295 K room temperature, 250 K is 45 K lower. Experiment is 234.32 K, 60.68 K below 295 K.
- WRONG | Switch relativity off and gold goes silver-white like every other metal. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://www.nature.com/articles/s41524-019-0266-0 | [X10; silver-every-metal] Re-read for this fix: Prandini, Introduction, identifies both gold and copper as coloured elemental metals. This is the dek copy of X4, covered by the same correction line.
- MINOR | the eye and brain invent it where the spectrum has a gap, so its colour lives in perception. | https://graphics.stanford.edu/courses/cs178-11/CS178FinalExamReviewSolutions2011.pdf | [X11; magenta-brain] Re-read for this fix: Stanford CS178 review solution 2 says no single wavelength induces magenta. A mixture-of-wavelengths description avoids implying a missing physical wavelength interval.
- CONFIRMED | Gold is yellow. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [gold-yellow] Retained checker confirmation, N2 line 18. Pyykkö and Desclaux p. 279 relates the colour to stronger blue/violet absorption; the later Romaniello calculation supports the relativistic account.
- CONFIRMED | Mercury is liquid. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [mercury-liquid] Retained checker confirmation, N2 line 19. Calvo p. 7583 identifies mercury as the elemental metallic liquid at room temperature; the temperature qualification matters.
- CONFIRMED | Gold is yellow and mercury is liquid for the same reason, and the reason is special relativity. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf; https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [same-relativity] Retained checker confirmation, N2 line 20. Pyykkö and Romaniello support gold; Calvo supplies the mercury calculation. Both effects involve relativity.
- CONFIRMED | Almost every metal is the same colour: a white-grey shine | https://www.nature.com/articles/s41524-019-0266-0 | [metal-colours] Retained checker confirmation, N2 line 21. Prandini describes broadly high, flat visible reflectivity for nearly all metals, supporting roughly even reflection, without implying perfect reflection.
- CONFIRMED | They look alike because a clean metal reflects the whole visible spectrum back at you more or less evenly. | https://www.nature.com/articles/s41524-019-0266-0 | [metal-reflection] Retained checker confirmation, N2 line 22. Prandini describes broadly high, flat visible reflectivity for nearly all metals, supporting roughly even reflection, without implying perfect reflection.
- CONFIRMED | Only two everyday metals break ranks. | https://www.nature.com/articles/s41524-019-0266-0 | [two-metals] Retained checker confirmation, N2 line 23. Prandini identifies gold and copper as coloured elemental metals; the page limits its two-metal comparison to everyday examples.
- CONFIRMED | Copper is warm. | https://www.nature.com/articles/s41524-019-0266-0; https://periodic-table.rsc.org/element/29/copper | [copper-warm] Retained checker confirmation, N2 line 24. Prandini identifies gold and copper as coloured elemental metals; the page limits its two-metal comparison to everyday examples.
- CONFIRMED | And almost every metal is solid. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [solid-metals] Retained checker confirmation, N2 line 26. Calvo p. 7583 identifies mercury as the elemental metallic liquid at room temperature; the temperature qualification matters.
- CONFIRMED | liquid you can pour at room temperature | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [pour-room] Retained checker confirmation, N2 line 27. Calvo p. 7583 identifies mercury as the elemental metallic liquid at room temperature; the temperature qualification matters.
- CONFIRMED | mercury, which freezes only at −39 °C, far below anything its neighbours in the periodic table will tolerate. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-freezes] Retained checker confirmation, N2 line 28. Calvo gives 234.32 K for Hg, 692.68 K for Zn and 594.22 K for Cd; Norrby also compares Au. Hg converts to -38.83 °C.
- CONFIRMED | The colour in the ring on your finger is a relativistic effect. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [ring-relativity] Retained checker confirmation, N2 line 31. Pyykkö and Desclaux p. 279 relates the colour to stronger blue/violet absorption; the later Romaniello calculation supports the relativistic account.
- CONFIRMED | the 1s, closest to the nucleus. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [core-1s] Retained checker confirmation, N2 line 32. Pyykkö p. 277 and Norrby p. 111 support the Bohr speed estimate. This is the stated toy model; nuclear charge supplies the pull, and these are not measured orbital trajectories.
- CONFIRMED | The heavier the nucleus, the harder it pulls, and the faster that electron must move to keep from falling in. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [nuclear-pull] Retained checker confirmation, N2 line 33. Pyykkö p. 277 and Norrby p. 111 support the Bohr speed estimate. This is the stated toy model; nuclear charge supplies the pull, and these are not measured orbital trajectories.
- CONFIRMED | A clean estimate (the Bohr model, exact in its scaling) says its speed is v/c = Zα | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [bohr-scaling] Retained checker confirmation, N2 line 34. Pyykkö p. 277 and Norrby p. 111 support the Bohr speed estimate. This is the stated toy model; nuclear charge supplies the pull, and these are not measured orbital trajectories.
- CONFIRMED | Z is the number of protons | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm; https://periodic-table.rsc.org/element/100/Fermium | [z-protons] Retained checker confirmation, N2 line 35. The RSC glossary defines atomic number as the proton count; the NIST list supplies element-number assignments.
- CONFIRMED | α ≈ 1/137 is the fine-structure constant. | https://physics.nist.gov/cuu/Constants/alpha.html | [alpha-constant] Retained checker confirmation, N2 line 36. NIST identifies alpha as the fine-structure constant, approximately 1/137.
- CONFIRMED | For hydrogen that's under a percent of light-speed. | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [hydrogen-speed] Retained checker confirmation, N2 line 37. Norrby gives the hydrogen Bohr speed as c/137, about 0.730 percent of c.
- CONFIRMED | Zα reaches one half at Z ≈ 68 | https://physics.nist.gov/cuu/Constants/alpha.html; git show f5e5f84f34:research/relativistic-gold/verify.mjs; https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [half-speed] Retained checker confirmation, N2 line 38. The page model gives Z = 1/(2 alpha) = 68.517999542, between erbium and thulium in the rare-earth sequence.
- CONFIRMED | so in every element heavier than that, a core electron is moving faster than half the speed of light. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [heavier-core-speed] Retained checker confirmation, N2 line 39. Pyykkö p. 277 and Norrby p. 111 support the Bohr speed estimate. This is the stated toy model; nuclear charge supplies the pull, and these are not measured orbital trajectories.
- CONFIRMED | At gold (Z = 79) | https://physics.nist.gov/PhysRefData/Handbook/Tables/goldtable1.htm | [gold-z] Retained checker confirmation, N2 line 40. NIST gives atomic number 79 for gold.
- CONFIRMED | that electron runs at 0.58 c, so γ ≈ 1.22: it behaves as if 22% heavier than an electron at rest. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; git show f5e5f84f34:research/relativistic-gold/verify.mjs | [gold-speed-mass] Retained checker confirmation, N2 line 41. The cited model at Z = 79 gives v/c = 0.576490853 and gamma = 1.223835016, supporting the rounded gold figures.
- CONFIRMED | relativistic mass grows by the factor γ = 1/√(1−(v/c)²). | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [mass-gamma] Retained checker confirmation, N2 line 42. Norrby p. 111 gives the Lorentz mass factor in the relativistic-mass convention, without changing invariant rest mass.
- CONFIRMED | the size of the orbit scales as 1/γ, so the 1s shell of gold pulls in by about 18%. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [radius-scaling] Retained checker confirmation, N2 line 43. The cited Bohr heuristic gives 1/gamma = 0.817103602 at Z = 79, an 18.28964 percent reduction; it is not an exact many-electron radius.
- CONFIRMED | The atom's innermost layer shrinks because its electron is fast enough for Einstein to matter. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [core-shrinks] Retained checker confirmation, N2 line 44. The cited Bohr heuristic gives 1/gamma = 0.817103602 at Z = 79, an 18.28964 percent reduction; it is not an exact many-electron radius.
- CONFIRMED | But the effect reaches the bonding shell too. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [contraction-outward] Retained checker confirmation, N2 line 45. Pyykkö pp. 277-278 extends direct contraction to valence s shells. X3 replaces the misleading core-to-valence causal wording.
- CONFIRMED | Every other s electron has to stay orthogonal to that pulled-in core | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [orthogonality] Retained checker confirmation, N2 line 46. Norrby p. 111 discusses orbital orthogonality. This previously present statement was removed as part of X3; the orthogonality claim itself was not rejected.
- CONFIRMED | the 6s, the one that actually does the bonding and sets the colour | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [bonding-sixs] Retained checker confirmation, N2 line 48. Pyykkö pp. 277-279 and Norrby p. 111 support the role of 6s in bonding, with 5d admixture; the page abbreviates the full conduction-band account.
- CONFIRMED | their orbitals contract directly and fall in energy. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [sixs-lowered] Retained checker confirmation, N2 line 49. Pyykkö pp. 277-278 distinguishes direct s contraction and stabilization from indirect d/f expansion and destabilization through increased screening. X3 makes that distinction explicit.
- CONFIRMED | Full relativistic calculations put gold's 6s contraction at about 18% as well (Pyykkö & Desclaux, 1979). | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [sixs-eighteen] Retained checker confirmation, N2 line 50. N2 inspected Figure 4 on Pyykkö p. 280: the Au 6s radial ratio is approximately 0.82. This is a different orbital from the 1s toy.
- CONFIRMED | the contracted s and p orbitals screen the nuclear pull more strongly, so the d and f orbitals expand and rise in energy. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [d-up] Retained checker confirmation, N2 line 51. Pyykkö pp. 277-278 distinguishes direct s contraction and stabilization from indirect d/f expansion and destabilization through increased screening. X3 makes that distinction explicit.
- CONFIRMED | The gap between the filled 5d band and the 6s level | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [gap-narrows] Retained checker confirmation, N2 line 52. Pyykkö p. 279 reports a 2.38 eV 5d-to-(6s + 6p) interband result. The rounded 2.4 eV corresponds to 516.600827 nm; 6s abbreviates the mixed conduction band.
- CONFIRMED | the gap a photon has to cross to be absorbed | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [photon-gap] Retained checker confirmation, N2 line 53. Pyykkö p. 279 reports a 2.38 eV 5d-to-(6s + 6p) interband result. The rounded 2.4 eV corresponds to 516.600827 nm; 6s abbreviates the mixed conduction band.
- CONFIRMED | A metal looks coloured when it absorbs part of the visible band and reflects the rest. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [coloured-metal] Retained checker confirmation, N2 line 54. Pyykkö and Desclaux p. 279 relates the colour to stronger blue/violet absorption; the later Romaniello calculation supports the relativistic account.
- CONFIRMED | gold would reflect visible wavelengths more evenly and look like silver. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [gold-off] Retained checker confirmation, N2 line 55. Pyykkö p. 279 supports silver-like nonrelativistic gold and weaker effects in Ag; Romaniello supplies the approximately 3.5 eV Au onset. X7 qualifies absolute absorption/reflection wording.
- CONFIRMED | That is already silver's broad pattern, one row up with weaker relativistic effects. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [silver-light] Retained checker confirmation, N2 line 56. Pyykkö p. 279 supports silver-like nonrelativistic gold and weaker effects in Ag; Romaniello supplies the approximately 3.5 eV Au onset. X7 qualifies absolute absorption/reflection wording.
- CONFIRMED | 5d→6s edge 2.4 eV (≈517 nm) | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [gold-edge] Retained checker confirmation, N2 line 57. Pyykkö p. 279 reports a 2.38 eV 5d-to-(6s + 6p) interband result. The rounded 2.4 eV corresponds to 516.600827 nm; 6s abbreviates the mixed conduction band.
- CONFIRMED | 4d→5s edge 3.9 eV (≈318 nm, UV) | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://www.nature.com/articles/s41524-019-0266-0; https://pubs.rsc.org/en/content/articlehtml/2022/mh/d1mh01163d; https://journals.aps.org/prb/abstract/10.1103/PhysRevB.49.2104 | [silver-edge] Retained checker confirmation, N2 line 58. Prandini gives an approximately 4 eV Ag edge; N2 also located 3.9 eV interband evidence in the Li et al. primary-paper abstract. 3.9 eV converts to 317.908201 nm.
- CONFIRMED | Stronger absorption of shorter-wavelength blue and violet leaves the reflected light weighted toward yellows and reds, the colour of the ring. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [absorbs-all-blue] Retained checker confirmation, N2 line 59. Pyykkö p. 279 supports stronger blue/violet absorption. X6/X7 clarify that the approximately 517 nm edge is green and the strip is an illustrative sharp threshold.
- CONFIRMED | Silver's gap is already so wide that its edge sits in the ultraviolet whether or not relativity is on, so it reflects visible wavelengths more evenly and looks white. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [silver-both-states] Retained checker confirmation, N2 line 60. Pyykkö p. 279 supports silver-like nonrelativistic gold and weaker effects in Ag; Romaniello supplies the approximately 3.5 eV Au onset. X7 qualifies absolute absorption/reflection wording.
- CONFIRMED | direct relativistic contraction of the s shells, including 6s; stronger screening raises 5d; the 5d–6s gap brought into the visible, with its edge in green; shorter-wavelength blue and violet absorbed more strongly; the reflected light looks yellow. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [relativity-chain] Retained checker confirmation, N2 line 61. Pyykkö pp. 277-279 supports orbital shifts and selective absorption. X3/X6 now distinguish direct s contraction, indirect d shifts and the green edge.
- CONFIRMED | Mercury sits one square past gold, at Z = 80 | https://physics.nist.gov/PhysRefData/Handbook/Tables/mercurytable1.htm | [hg-z] Retained checker confirmation, N2 line 64. NIST gives Hg atomic number 80, immediately after Au at 79.
- CONFIRMED | mercury's 6s shell is full: two electrons, paired. | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [hg-pair] Retained checker confirmation, N2 line 65. Norrby p. 113 describes a filled contracted 6s shell with reduced participation in metallic bonding; NIST gives 5d10 6s2. Half-withdrawn is qualitative.
- CONFIRMED | Relativity pulls that pair in so tightly and lowers it so far that the two electrons become reluctant to take part in bonding at all | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [hg-stabilization] Retained checker confirmation, N2 line 66. Norrby p. 113 describes a filled contracted 6s shell with reduced participation in metallic bonding; NIST gives 5d10 6s2. Half-withdrawn is qualitative.
- CONFIRMED | Metal atoms hold together by sharing their outer electrons into a common sea; mercury's are half-withdrawn from the deal. | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [metal-sea] Retained checker confirmation, N2 line 67. Norrby p. 113 describes a filled contracted 6s shell with reduced participation in metallic bonding; NIST gives 5d10 6s2. Half-withdrawn is qualitative.
- CONFIRMED | a weak bond means a low melting point. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf; https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [weak-low] Retained checker confirmation, N2 line 69. Norrby compares similar fusion entropies but much lower Hg fusion enthalpy; Calvo supplies the relativistic bulk calculation. The statement is about mercury.
- CONFIRMED | as an honest ab-initio simulation of mercury freezing (Calvo, Pahl, Wormit & Schwerdtfeger). | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [2013-simulation] Retained checker confirmation, N2 line 70. Calvo et al. 2013 compares relativistic and nonrelativistic Monte Carlo simulations using a quantum diatomics-in-molecules model based on ab-initio potential curves.
- CONFIRMED | melting point ≈ 250 K | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-model250] Retained checker confirmation, N2 line 71. Calvo p. 7584 gives model melting points 355 K and 250 K and experiment 234.32 K. Thus the model drop is 105 K, 250 < 295 < 355, and experiment is -38.83 °C.
- CONFIRMED | below room temperature, so mercury is liquid (the measured value is 234 K; the simulation lands close). | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-liquid-model] Retained checker confirmation, N2 line 72. Calvo p. 7584 gives model melting points 355 K and 250 K and experiment 234.32 K. Thus the model drop is 105 K, 250 < 295 < 355, and experiment is -38.83 °C.
- CONFIRMED | Off: ≈ 355 K [...] above room temperature | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-model355] Retained checker confirmation, N2 line 73. Calvo p. 7584 gives model melting points 355 K and 250 K and experiment 234.32 K. Thus the model drop is 105 K, 250 < 295 < 355, and experiment is -38.83 °C.
- CONFIRMED | above room temperature, so mercury would be a solid metal you could hold, like its neighbours. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-solid-model] Retained checker confirmation, N2 line 74. Calvo p. 7584 gives model melting points 355 K and 250 K and experiment 234.32 K. Thus the model drop is 105 K, 250 < 295 < 355, and experiment is -38.83 °C.
- CONFIRMED | The ~105 K gap is relativity's whole signature. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-gap] Retained checker confirmation, N2 line 75. Calvo p. 7584 gives model melting points 355 K and 250 K and experiment 234.32 K. Thus the model drop is 105 K, 250 < 295 < 355, and experiment is -38.83 °C.
- CONFIRMED | experimental melting point −38.83 °C. | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf | [hg-experimental] Retained checker confirmation, N2 line 76. Calvo p. 7584 gives model melting points 355 K and 250 K and experiment 234.32 K. Thus the model drop is 105 K, 250 < 295 < 355, and experiment is -38.83 °C.
- CONFIRMED | gold's 2.4 eV edge and mercury's two melting points come from full relativistic many-electron calculations a hydrogen-like cartoon cannot reproduce | https://moodle2.units.it/pluginfile.php/721750/mod_resource/content/1/liquid%20Hg%20Calvo_et_al-2013-Angewandte_Chemie_International_Edition.pdf; https://web.uvic.ca/~mcindoe/424/relativity.pdf | [computed-colour-source] Retained checker confirmation, N2 line 77. Pyykkö p. 279 supplies the gold band calculation and Calvo supplies the many-body Hg model. The hydrogenic dial does not derive these reported quantities.
- CONFIRMED | the speed of that electron is real | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [speed-real] Retained checker confirmation, N2 line 79. Pyykkö p. 277 and Norrby p. 111 support the Bohr speed estimate. This is the stated toy model; nuclear charge supplies the pull, and these are not measured orbital trajectories.
- CONFIRMED | you can watch it cross half the speed of light somewhere around the rare-earth elements, long before you reach the metals whose strangeness it explains. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; git show f5e5f84f34:research/relativistic-gold/verify.mjs; https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [rare-earth-crossing] Retained checker confirmation, N2 line 80. The page model gives Z = 1/(2 alpha) = 68.517999542, between erbium and thulium in the rare-earth sequence.
- CONFIRMED | Einstein worked all this out for things moving fast through space. | https://moodle2.units.it/pluginfile.php/774438/mod_resource/content/1/J%20Chem%20Ed%201991%20relativistic%20effects.pdf | [einstein-space] Retained checker confirmation, N2 line 81. Norrby p. 111 dates special relativity to 1905. This credits the general theory, not a gold-chemistry calculation by Einstein.
- CONFIRMED | gold's edge climbs to ~3.5 eV | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [off-edge] Retained checker confirmation, N2 line 82. Romaniello reports a nonrelativistic Au onset around 3.5 eV; hc/E gives 354.240567 nm, in the ultraviolet.
- CONFIRMED | Silver barely moves: its 4d–5s gap is already wide, which is why silver is white in the real, relativistic world too. | https://web.uvic.ca/~mcindoe/424/relativity.pdf; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [silver-barely] Retained checker confirmation, N2 line 84. Pyykkö p. 279 supports silver-like nonrelativistic gold and weaker effects in Ag; Romaniello supplies the approximately 3.5 eV Au onset. X7 qualifies absolute absorption/reflection wording.
- CONFIRMED | Magenta is a colour with no wavelength of its own | https://graphics.stanford.edu/courses/cs178-11/CS178FinalExamReviewSolutions2011.pdf | [magenta-no-wavelength] Retained checker confirmation, N2 line 88. Stanford CS178 review solution 2 explains that no single wavelength induces magenta; it is a non-spectral colour.
- CONFIRMED | clocks on GPS satellites and on Scott Kelly's wrist drift by microseconds because they move fast through space | https://assets.science.nasa.gov/content/dam/science/astro/programs/physics-of-the-cosmos/documents/brochures-factsheets/jan-2015-aas/GR_Centennial_Brochure-Final.pdf | [relates-gps] Retained checker confirmation, N2 line 90. N2 read the NASA brochure: satellite motion contributes about -7 microseconds per day, separately from gravitational and net corrections.
- CONFIRMED | clocks on GPS satellites and on Scott Kelly's wrist drift by microseconds because they move fast through space | https://www.theguardian.com/science/2017/oct/29/scott-kelly-astronaut-interview-space-younger-twin-endurance; git show f5e5f84f34:public/strata/the-time-traveler/index.html | [relates-kelly] Retained checker confirmation, N2 line 91. N2 checked the interview context: the additional difference was 13 milliseconds after a year. The page gives no duration; milliseconds are thousands of microseconds.
- CONFIRMED | Both hinge on the electron being a wave, not a ball. | https://bohr.physics.berkeley.edu/classes/221/notes/spdirac.pdf | [electron-wave] Retained checker confirmation, N2 line 92. N2 checked Berkeley notes section 16 on bound-state Dirac wave functions and probability density.
- CONFIRMED | Pyykkö & Desclaux, Acc. Chem. Res. 12 (1979) 276 | https://api.crossref.org/works/10.1021%2Far50140a002 | [citation-1979] Retained checker confirmation, N2 line 93. N2 checked the named authors, year, journal, volume and starting page/article number against publisher-deposited Crossref metadata. This confirms the citation, not every attributed figure.
- CONFIRMED | Pyykkö, Chem. Rev. 88 (1988) 563 | https://api.crossref.org/works/10.1021%2Fcr00085a006 | [citation-1988] Retained checker confirmation, N2 line 94. N2 checked the named authors, year, journal, volume and starting page/article number against publisher-deposited Crossref metadata. This confirms the citation, not every attributed figure.
- CONFIRMED | Norrby, J. Chem. Educ. 68 (1991) 110 | https://api.crossref.org/works/10.1021%2Fed068p110 | [citation-1991] Retained checker confirmation, N2 line 95. N2 checked the named authors, year, journal, volume and starting page/article number against publisher-deposited Crossref metadata. This confirms the citation, not every attributed figure.
- CONFIRMED | Glantschnig & Ambrosch-Draxl, New J. Phys. 12 (2010) 103048 | https://api.crossref.org/works/10.1088%2F1367-2630%2F12%2F10%2F103048 | [citation-2010] Retained checker confirmation, N2 line 96. N2 checked the named authors, year, journal, volume and starting page/article number against publisher-deposited Crossref metadata. This confirms the citation, not every attributed figure.
- CONFIRMED | Calvo, Pahl, Wormit & Schwerdtfeger, Angew. Chem. Int. Ed. 52 (2013) 7583 | https://api.crossref.org/works/10.1002%2Fanie.201302742 | [citation-2013] Retained checker confirmation, N2 line 97. N2 checked the named authors, year, journal, volume and starting page/article number against publisher-deposited Crossref metadata. This confirms the citation, not every attributed figure.
- CONFIRMED | Binding is for a bare point nucleus, unscreened, so it overstates real inner-shell energies | https://bohr.physics.berkeley.edu/classes/221/notes/spdirac.pdf | [binding-point] Retained checker confirmation, N2 line 101. N2 checked Berkeley section 16: a point-Coulomb one-electron model omits finite nuclear size and many-electron screening. The displayed energy is not a neutral-Au measurement.
- CONFIRMED | the ratio of relativistic to non-relativistic, the thing this is about, is honest. | https://bohr.physics.berkeley.edu/classes/221/notes/spdirac.pdf | [binding-ratio] Retained checker confirmation, N2 line 102. The point-Coulomb Dirac and nonrelativistic formulas give a binding ratio 1.1006527078 at Z = 79; this is a model ratio, not an exact neutral-atom ratio.
- CONFIRMED | silver · Z 47 | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [snap-silver] Retained checker confirmation, N2 line 127. N2 checked the snap labels against NIST: Ag 47, Au 79, Hg 80, Pb 82, U 92 and H 1.
- CONFIRMED | mercury · Z 80 | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [snap-mercury] Retained checker confirmation, N2 line 128. N2 checked the snap labels against NIST: Ag 47, Au 79, Hg 80, Pb 82, U 92 and H 1.
- CONFIRMED | uranium · Z 92 | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [snap-uranium] Retained checker confirmation, N2 line 129. N2 checked the snap labels against NIST: Ag 47, Au 79, Hg 80, Pb 82, U 92 and H 1.
- CONFIRMED | hydrogen · Z 1 | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [snap-hydrogen] Retained checker confirmation, N2 line 130. N2 checked the snap labels against NIST: Ag 47, Au 79, Hg 80, Pb 82, U 92 and H 1.
- CONFIRMED | silver · Z 47 gold · Z 79 mercury · Z 80 lead · Z 82 uranium · Z 92 hydrogen · Z 1 | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm | [snap-all] Retained checker confirmation, N2 line 131. N2 checked the snap labels against NIST: Ag 47, Au 79, Hg 80, Pb 82, U 92 and H 1.
- CONFIRMED | GOLD [...] 5d→6s edge 3.5 eV (≈354 nm, UV) | git show f5e5f84f34:public/strata/the-colour-of-gold/index.html; https://pure.rug.nl/ws/files/6686032/2005JChemPhysRomaniello.pdf | [gold-edge-off-readout] Retained checker confirmation, N2 line 132. Romaniello reports a nonrelativistic Au onset around 3.5 eV; hc/E gives 354.240567 nm, in the ultraviolet.
- CONFIRMED | a closed, contracted, almost noble-gas-like cap. | https://web.uvic.ca/~mcindoe/424/relativity.pdf | [noble-gas-cap] Retained checker confirmation, N2 line 135. Pyykkö p. 279 and Norrby p. 113 use a qualified noble-gas analogy for the contracted filled shell; this does not quantify bulk cohesion.
- CONFIRMED | (added) "silver, iron, tin, platinum, aluminium, lead" | https://periodic-table.rsc.org/element/47/silver; https://periodic-table.rsc.org/element/26/iron; https://periodic-table.rsc.org/element/50/tin; https://periodic-table.rsc.org/element/78/platinum; https://periodic-table.rsc.org/element/13/aluminium; https://periodic-table.rsc.org/element/82/lead; https://periodic.lanl.gov/47.shtml | [added-metal-examples] Retained checker confirmation, N2 line 143. N2 read RSC descriptions of Fe, Sn, Pt, Al and Pb and LANL on Ag; these support the listed grey, white or silvery appearances.
- CONFIRMED | (added) "carbon" at "Z = 6"; "iron" at "Z = 26"; "xenon" at "Z = 54"; "erbium" at "Z = 68" | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm; git show f5e5f84f34:public/strata/the-colour-of-gold/index.html | [added-dial-names] Retained checker confirmation, N2 line 144. N2 checked NIST for carbon 6, iron 26, xenon 54 and erbium 68.
- CONFIRMED | (added) "H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm" | https://physics.nist.gov/PhysRefData/Handbook/atomic_number_a.htm; https://periodic-table.rsc.org/element/100/Fermium; https://periodic-table.rsc.org/ | [added-dial-symbols] Retained checker confirmation, N2 line 145. N2 checked the 100-symbol array against NIST through 99 and the RSC table through fermium 100; all displayed symbols matched.

## Findings

- [fixed] X1 (WRONG, gold-only-colour-identifiable-metal): Removed the exclusive one-metal wording from the HTML introduction, dek and markdown opening; added one correction line in HTML and markdown. Share-image disposition: share card rebuilt at landing from the corrected dek. The repair pass inspected the PNG and its derived WebP; neither was regenerated here.
- [fixed] X2 (MINOR, unsupported-late-seventies-priority): Replaced the unsupported until-the-late-1970s priority gloss with discussion in a 1979 chemistry review. MINOR, recorded here with no on-page correction line.
- [fixed] X3 (WRONG, reversed-core-screening): Replaced reversed screening and the core-driven contraction account with direct s contraction and indirect d/f expansion through increased screening; synchronized the summary chain, dek, body and relates note. Added the mirrored correction.
- [fixed] X4 (WRONG, all-other-metals-silver-white): Changed every other metal to most metals in HTML; the correction line also covers X10 in the dek.
- [fixed] X5 (MINOR, bulk-mercury-frozen-gas-analogy): Deleted the frozen-gas comparison while retaining weak metallic bonding. MINOR, recorded here with no on-page correction line.
- [fixed] X6 (WRONG, two-point-four-ev-labelled-blue): Named the 2.4 eV edge green in HTML, toggle text, dek, body and both verifier copies; the verifier now checks the stated 495-570 nm interval. Retained stronger shorter-wavelength blue/violet absorption and added the mirrored correction.
- [fixed] X7 (WRONG, zero-visible-absorption): Qualified the gold-off prose, both spectrum descriptions, accessible labels, markdown body and verifier labels; described the sharp strip as illustrative and removed zero-absorption/perfect-reflection claims. Added the mirrored correction.
- [fixed] X8 (WRONG, optical-calculation-misdated-1979): Changed 1979 calculations to calculations reviewed in 1979 in the off-state note. The mirrored correction names the 1971 calculation and the 1979 review.
- [fixed] X9 (WRONG, mercury-105-k-below-room): Separated the 105 K model reduction from the below-room-temperature statement in the dek and body, retaining 355 K and 250 K from Calvo. The mirrored correction computes the 45 K difference from 295 K.
- [fixed] X10 (WRONG, all-other-metals-silver-white): Changed the dek comparison to most metals, completing the second copy of X4. Both items retain WRONG and share one correction line.
- [fixed] X11 (MINOR, ambiguous-magenta-spectrum-gap): Replaced the magenta spectrum-gap metaphor in the relates note with perception from a mixture of wavelengths. MINOR, recorded here with no on-page correction line.

## Scope and remaining uncertainty

This record covers the directed triage and the retained CONFIRMED claims, not a new full-page pass. The four UNVERIFIABLE entries in research/assay-line/queue-1014c/the-colour-of-gold/N2-codex.md remain outside this triage: century-textbooks, most-precious, cited-not-computed and silver-edge-off-readout. The latter two concern the untraced 4.0 eV nonrelativistic silver value. No claim is made that these uncertainties have been resolved. The previous orthogonality claim remains recorded as confirmed historical text, although it was removed while repairing the screening explanation. The public verifier is a verbatim layer-only mirror of research/relativistic-gold/verify.mjs; no shared publication files were changed.