Assertion: stone | /r/HasProperty | moved
Facets:
Source sentences:
text: If you examine a specimen of precious opal under bright light, play-of-color can be observed in three situations: 1) when the stone is moved, 2) when the light source is moved, or, 3) when the angle of observation is changed.
text: Precious Opal "Precious opal" flashes iridescent colors when it is viewed from different angles, when the stone is moved, or when the light source is moved.
text: The line, or the "eye", tracks back and forth across the dome of the stone as the stone is moved, as the light source is moved, or as the head of the observer is moved.