Assertion: slate | /r/HasProperty | -grained metamorphic rock
Facets:
Source sentences:
text: Slate is a fine-grained metamorphic rock.
text: Second only to wood as a natural, traditional, roofing material, slate is a fine-grained sedimentary rock that has topped castles and large buildings for centuries in Europe.
text: Slate is a fine-grained metamorphic rock that splits into thin, smooth-surfaced layers.