Assertion: jet | /r/HasProperty | gemstone
Facets:
Source sentences:
text: Jet (gemstone), a black or brown semi-precious mineraloid
text: Jet (gemstone), a black or brown semi-precious mineraloid
text: Jet is a type of lignite, the lowest rank of coal, and is a gemstone.
text: Jet is a gemstone made from decaying wood under extreme pressure.