Assertion: black swan's feather | /r/CapableOf | show blue or bluish-purple sheen
Facets:
value: often
type: TEMPORAL
value: in bright sunlight
type: LOCATION
Source sentences:
text: The rook is a fairly large bird, at 45 to 47 cm (18 to 19 in) in length, with black feathers that often show a blue or bluish-purple sheen in bright sunlight.