Domain: Natural Science — Geology & Geophysics
Target concept: Mineral fluorescence under ultraviolet light (calcite or fluorite luminescence)

Video generation prompt: In a dark room, place a calcite or fluorite mineral on the table and repeatedly expose it to a handheld ultraviolet lamp by turning it on and off.

Evaluation guide:
(i) Target concept: Instantaneous, reversible, UV-triggered visible luminescence from mineral activators.
Minimum mechanism: UV photons are absorbed by activator ions within the crystal lattice (e.g., Mn²⁺ or rare-earth ions substituted into the calcite or fluorite structure) → electrons in these activator ions are excited to higher energy states → rapid radiative relaxation back to the ground state → visible photons emitted; zero delay or persistence beyond the moment of UV exposure; emission spectrum determined solely by activator identity and host lattice.
(ii)Storyline: [Frame 0–t1] Dark room, static table, inert mineral visible in ambient blackness. → [t1] Hand enters frame holding UV lamp, positions it near mineral (no contact). → [t2] Lamp switches ON → immediate onset of colored surface glow *only on mineral*. → [t3] Lamp switches OFF → glow vanishes within one frame. → [t4] Lamp switches ON again → identical glow reappears. → [t5] Lamp switches OFF again → glow vanishes identically. Throughout: fixed viewpoint, no camera motion, no ambient light intrusion, no object displacement, no emission outside mineral boundary.

Manual:
Experimental Procedure
1. Place a calcite or fluorite mineral specimen on a table in a completely dark room.
2. Hold a handheld longwave ultraviolet (365 nm) lamp near the mineral.
3. Turn the lamp on → observe fluorescence → turn lamp off → observe fluorescence ceasing.
4. Repeat the on/off cycle at least twice.
Observation of Experimental Phenomena
When UV lamp is ON: mineral emits visible colored light (e.g., red/orange for calcite; blue/violet for fluorite) — self-luminous, surface-localized, no persistence.
When UV lamp is OFF: emitted light disappears immediately; mineral returns to inert, non-glowing state; no afterglow or residual color.
Summary of Experimental Principles
Fluorescence is photon absorption at UV wavelength followed by near-instantaneous re-emission at longer visible wavelengths. Calcite and fluorite contain activator impurities (e.g., Mn²⁺, rare earths) that enable this process. Emission ceases within nanoseconds of UV removal — no phosphorescence.

Prompt Grounding rubric:
level_1: None of the required elements appear: no mineral specimen on a table, no handheld UV lamp, no dark-room setting, and no lamp on/off action; the core setup for this UV-fluorescence demonstration is simply not shown.
level_2: Some but not all core elements appear: for example the UV lamp is shown without any mineral specimen, or the mineral is shown without a lamp ever appearing near it; or the room is not convincingly dark; and no clear on/off toggling of the lamp occurs at all.
level_3: A mineral specimen (calcite or fluorite) sits on a table in a dark room; a handheld UV lamp is visibly held near the mineral; the lamp is switched on at least once, producing a visible change in illumination, and switched off at least once, with a clear visual difference between the lit and unlit states.
level_4: All conditions for score 3 are met, AND the lamp stays in roughly the same position relative to the mineral across each on/off cycle rather than being repositioned each time, AND the mineral itself does not move on the table, AND no unrelated hands, tools, or objects enter the frame, AND the lamp and the mineral remain visible together in a single fixed shot.
level_5: All conditions for score 4 are met, AND the lamp is clearly held by a hand (not mounted on a stand or moved by an unseen mechanism), AND the mineral's crystal form is recognizable as calcite or fluorite (e.g., a rhombohedral cleavage block for calcite, or a cubic/blocky cleavage form for fluorite), AND each on/off transition reads as a deliberate manual toggle rather than an automatic blink or timer cycle, AND the darkness of the room stays uniformly black between cycles with no stray ambient light appearing.

Scientific and Causal Correctness rubric:
level_1: No fluorescence at all: the mineral shows no colored glow while the UV lamp is on; or the emitted light is white/colorless rather than a visible hue; or the glow continues essentially unchanged for several seconds after the lamp is switched off; or the mineral glows even while the lamp is clearly off.
level_2: A colored glow appears, but the color is one that neither calcite nor fluorite can plausibly show under longwave UV, e.g., pure white, black/no color, or a metallic glint rather than a fluorescent hue; or the glow visibly starts before the lamp switches on, or clearly lingers for more than about a second after the lamp switches off (suggesting phosphorescence rather than fluorescence); or the mineral's own body color changes rather than an added glow appearing.
level_3: A colored glow appears only while the UV lamp is on and fades out essentially as soon as the lamp turns off; the emitted color matches a real fluorescence for the mineral shown: red, orange, yellow, or pink for calcite, or blue, violet, or green for fluorite; the mineral's own body color and shape stay the same; no colored glow comes from the table, the lamp body, or the surrounding air.
level_4: All conditions for score 3 are met, AND the fluorescence color stays the same hue across every on-cycle (it does not shift from, say, blue to red between repetitions), AND there is no separate afterglow once the lamp is off distinct from the bright on-state, AND the glow reads as an emitted color rather than a change in surface shine or reflectivity.
level_5: All conditions for score 4 are met, AND the glow is clearly brighter and more saturated than could be explained by the mineral simply reflecting the lamp's own UV light, AND the colored glow stays confined to the mineral's surface with no colored halo bleeding onto the table or air around it, AND the fluorescence color is one that is genuinely documented for the mineral type shown (never, for example, a red glow from a piece shown as fluorite, or a blue glow from a piece shown as calcite).

Spatiotemporal Consistency rubric:
level_1: Severe continuity break: the mineral or the UV lamp vanishes and reappears, or jumps to a new position with no visible movement in between; the clip cuts to a black frame or a hard scene change; the room's ambient lighting changes for a reason other than the lamp switching on or off.
level_2: Noticeable drift or mismatch: the mineral shifts position on the table by more than roughly its own width between on/off cycles; the lamp visibly leaves and re-enters the frame between cycles; the glow snaps to full brightness with no visible spread from the point of contact, as if pasted on rather than genuinely illuminating the mineral; a shadow near the mineral appears or disappears with no change in the lamp's state.
level_3: The mineral stays fixed in the same spot on the table for the whole clip, and the lamp stays near the mineral throughout; the room's lighting changes only at the moments the lamp is switched on or off; nothing vanishes, reappears, or changes shape unexpectedly; there is no visible camera cut or camera movement: the clip reads as one continuous shot.
level_4: All conditions for score 3 are met, AND the UV beam's glow spreads outward from the lamp in a soft cone that lights mainly the mineral and the table right around it, rather than snapping on uniformly everywhere at once, AND any shadow cast by the lamp or the hand holding it keeps a consistent direction and softness across the clip, AND the mineral's outline and its contact with the table stay steady with no warping or sliding.
level_5: All conditions for score 4 are met, AND any hand or lamp movement while positioning the lamp is slow and settles into a still hold before each on/off toggle, with no rapid shaking, AND the mineral and the background keep a consistent relative position with no swimming or drifting between them, AND there is no visible flicker or strobing in the glow itself while the lamp is held steadily on: the brightness stays constant through each on period rather than pulsing.