Assertion: opal | /r/HasProperty | unique
Facets:
value: among precious gems
type: OTHER
value: like agates
type: OTHER
value: to a very high degree
type: OTHER
value: as a species
type: OTHER
Source sentences:
text: As a species, opal is so unique it has its own descriptive vocabulary.
text: They are an unique Australian souvenir.
text: However opals are unique because they display a rainbow-like display due to their intrinsic microstructure which diffracts white light into all the colours of the spectrum.
text: Like agates, every opal is unique.
text: All opals are unique –
text: The opals you see here are unique to a very high degree.
text: Opals are unique among precious gems because they do not take a regular crystalline shape but are instead amorphous.