Assertion: opal | /r/CapableOf | change color
Facets:
Source sentences:
text: Opals can change color based on what angle they are being viewed at.
text: Opals change color as they are viewed from different angles but not really under different light sources although if you look at some opals under fluorescent the play-of-color can be diminished because the fluorescent lights do not possess the full spectrum of color, so the display by the opal will be missing some hues.