Assertion: bluestone | /r/HasProperty | natural material
Facets:
Source sentences:
text: Be aware that bluestone is a natural material, and so even uniform sizes will have imperfections: small clefts or crevices, or rust stains, for instance.
text: Here, you also need to keep in mind that bluestone is a natural material and thus even uniform sizes might have imperfections, small clefts or rust stains.