Assertion: sponge | /r/HasProperty | rough
Facets:
value: for general use
type: PURPOSE
value: due to their structural spicules
type: CAUSE
Source sentences:
text: Sponges can be smooth and mushy, or they can be rough, hard, and prickly.
text: Most sponges are too rough for general use due to their structural spicules composed of calcium carbonate or silica.