Assertion: black opal | /r/HasProperty | mined in lightning ridge
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: Black Opal is the most valuable form of Opal mined in Lightning Ridge
text: Black Opals are usually mined in Lightning Ridge, New South Wales, and are the most famous, and sought-after type of opal.
text: Black Opals are usually mined in Lightning Ridge, New South Wales, and are the most famous, and sought-after type of opal.