Assertion: black opal | /r/CapableOf | display a myriad of rainbow colors
Facets:
Source sentences:
text: Black opals are the most precious type of opals, they have body color of black or dark gray (do note that black opal should not be completely black otherwise it would be completely worthless, it should displays a myriad of rainbow colors, the more colorful the better), sometimes dark green or blue are also called black opals.
text: Black opals display a myriad of rainbow colours, and the more colourful the better.