Assertion: concrete's material | /r/HasProperty | clay
Facets:
value: usually
type: DEGREE
Source sentences:
text: A brick is a block made of kiln-fired material, usually clay or shale, but also may be of lower quality mud, etc.
text: Also called building tile, structural terra cotta, hollow tile, and clay block, the material is an extruded clay shape with substantial depth that allows it to be laid in the same manner as other clay or concrete masonry.