Domain: Natural Science — Geology & Geophysics
Target concept: Mohs Hardness Scratch Test: Comparison between Quartz and Feldspar

Video generation prompt: On a worktable, quartz and pink feldspar are placed side by side; a hand first uses the quartz to scratch the feldspar, and then uses the feldspar to attempt to scratch the quartz.

Evaluation guide:
(i) Target concept: Relative hardness comparison via scratch test.
Minimum mechanism: A harder mineral leaves a permanent linear abrasion on a softer mineral"s surface upon sufficient normal force and lateral motion; the softer mineral cannot abrade the harder one under identical conditions.
(ii)Storyline: Frame 1–3: Static shot showing quartz and pink feldspar placed adjacent on worktable, clearly distinguishable by color and translucency. Frame 4–6: Hand enters, grasps quartz, presses and drags it across feldspar surface; feldspar surface develops a linear scratch at contact locus. Frame 7–8: Hand lifts quartz away, pauses briefly. Frame 9–10: Hand picks up pink feldspar, presses it against quartz surface, drags; quartz surface remains unmarked. All actions occur from fixed frontal viewpoint; minerals remain stationary; lighting is static; no off-screen actions or cuts.

Manual:
Experimental Procedure
1. Place quartz (translucent grayish-white crystal) and pink feldspar (opaque pink rock) side by side on a worktable.
2. Use hand to press quartz against feldspar surface and drag linearly to scratch.
3. Lift hand, then use pink feldspar to press against quartz surface and drag linearly to attempt scratching.
Observation of Experimental Phenomena
- Feldspar surface shows a visible linear scratch mark after quartz contact.
- Quartz surface shows no scratch mark after feldspar contact.
Summary of Experimental Principles
Quartz (Mohs hardness 7) is harder than pink feldspar (Mohs hardness 6), so quartz can scratch feldspar but feldspar cannot scratch quartz.

Prompt Grounding rubric:
level_1: The worktable is missing; or neither quartz nor pink feldspar appears; or only one of the two minerals appears; or the two minerals are not placed next to each other; or no hand appears; or no scratching action of any kind is shown.
level_2: Quartz and pink feldspar both sit on the worktable, but they are stacked, overlapping, or shown in separate shots rather than side by side; or the hand performs only one of the two scratching actions (quartz-on-feldspar or feldspar-on-quartz, not both); or the two actions happen at the same time or in reversed order rather than as two distinct, sequential events.
level_3: Quartz and pink feldspar sit side by side on the worktable; the hand carries out two distinct scratching actions in two visually separate moments; but at least one of the following is unclear: the color contrast between the translucent/grayish quartz and the opaque pink feldspar, or which mineral is doing the scratching versus being scratched in each action.
level_4: Quartz (translucent/grayish-white) and pink feldspar (opaque pink) sit side by side; the hand performs the two scratching actions in the correct order (quartz against feldspar first, then feldspar against quartz), with the identity and role of each mineral clear in both actions; neither mineral ever jumps position or duplicates; one small flaw remains (e.g., a brief moment where the hand blocks the contact point, a slight lighting flicker, or minor jerkiness that doesn't break the sense of continuity).
level_5: Quartz and pink feldspar keep their distinct color, shape, and position side by side throughout; the hand first brings quartz into visible contact with the feldspar's surface, then repositions to bring the feldspar into visible contact with the quartz's surface; both contacts are fully shown, uninterrupted, in the correct order, with the correct mineral acting as scratcher each time; no occlusion, lighting shift, repositioning glitch, or mineral duplication occurs.

Scientific and Causal Correctness rubric:
level_1: No contact between the two minerals ever produces a mark; or both minerals end up looking the same (both scratched, both unmarked, or both chipped); or the feldspar visibly leaves a scratch on the quartz; or the quartz fails to leave any scratch on the feldspar.
level_2: Contact happens in both directions, but the result contradicts Mohs hardness: both feldspar and quartz end up scratched, or neither shows any change despite visible contact, or only one shows a change and it's the wrong one (feldspar marking the quartz).
level_3: The feldspar shows a clear linear scratch after the quartz is dragged across it, and the quartz shows no scratch after the feldspar is dragged across it, but either the scratch's location doesn't line up with where contact happened, or the two minerals look similar enough in color/translucency that it's hard to tell which is which.
level_4: The feldspar shows a linear scratch exactly where the quartz contacted it, and the quartz stays unmarked exactly where the feldspar contacted it; quartz and feldspar remain visually distinguishable (translucent/grayish-white vs. opaque pink) throughout; one small scientific flaw remains, such as the feldspar's scratch looking like a deep chip rather than a shallow line, or a faint unrelated smudge appearing on the quartz.
level_5: The feldspar shows exactly one clean, shallow, linear scratch precisely where and in the direction the quartz was dragged; the quartz shows no mark, chip, or discoloration where the feldspar contacted it; the translucency of the quartz and the pink opacity of the feldspar stay clearly distinguishable before, during, and after both actions, so the cause-and-effect (which mineral scratches which) is never in doubt.

Spatiotemporal Consistency rubric:
level_1: Either mineral jumps to a new position between shots with no motion shown connecting them; the hand disappears and reappears without a visible path; the worktable's edges bend or warp; the lighting suddenly switches from shadow to bright highlight between consecutive shots; or an object flickers in and out of view.
level_2: A mineral changes position or angle with no visible motion getting it there; the hand starts the second scratching action before finishing the first, with no lift-off in between; the worktable's surface texture or shininess looks different from one moment to the next; or a shadow jumps in a way inconsistent with the light source.
level_3: Quartz and feldspar keep the same positions relative to each other on the worktable; the hand moves continuously between the two actions with no jump; the lighting stays steady in direction and brightness, but one moderate flaw remains, such as a visible jitter in a mineral's outline, the hand's fingers briefly blurring out of view during motion, or a minor mismatch in the background's perspective.
level_4: The minerals never teleport, the worktable never warps, the lighting never jumps, and the hand's motion never looks jerkier than natural human movement; the hand fully lifts and repositions smoothly between the two scratching actions; the minerals sit still and rigid throughout; one subtle flaw remains, such as a slight brightness flicker (under about 10%) or a faint seam where footage may have been joined, without affecting the objects' integrity.
level_5: Quartz and feldspar stay in the same relative position and orientation throughout with no visible drift; the hand's motion is fully continuous with no unexplained disappearance, no sudden speed change, and no ambiguity about where it is; the lighting and shadows evolve naturally with the hand's motion; the worktable's texture and reflectivity stay consistent; and there is no flicker, stutter, ghosting, or blending artifact between shots.