Assertion: tourmaline's color | /r/HasProperty | rare
Facets:
value: extremely
type: DEGREE
Source sentences:
text: This color is rare as well as the shape.
text: Their color comes from chromium, the same rare element that colors emeralds.
text: This color is rare as well as the shape.
text: The finest green tourmalines resemble top quality emeralds, but this color is extremely rare and highly desired.