Assertion: sponge's type | /r/HasProperty | cultured by ancient greeks
Facets:
value: for its dye
type: PURPOSE
Source sentences:
text: Another type of gastropod, the murex, was cultured by the ancient Greeks for its dye, known as "imperial purple," and the cloaks of some rulers were woven from long threads secreted by the bivalve species Pinna nobilis.