Assertion: opal's play | /r/HasProperty | lower quality
Facets:
value: often
type: TEMPORAL
Source sentences:
text: The top layer also acts as a magnifier, to emphasize the play of color of the opal beneath, which is often of lower quality.
text: The top layer also acts as a magnifier, to emphasize the play of color of the opal beneath, which is often of lower quality.