Assertion: mexican opal | /r/HasProperty | rare
Facets:
value: relatively
type: DEGREE
value: in large sizes
type: OTHER
value: very
type: DEGREE
Source sentences:
text: Fine Mexican opal is very rare in large sizes (over 50 carats) but is among the most beautiful.
text: Peruvian opal is relatively rare and is only found in the Andes mountains near San Patricio, Peru.