Assertion: obsidian | /r/HasProperty | amorphous material
Facets:
value: with no crystalline structure
type: OTHER
Source sentences:
text: It is an amorphous material known as a "mineraloid.
text: Obsidian is hard, brittle, and amorphous; it therefore fractures with sharp edges.
text: Obsidian is an amorphous stone with no crystalline structure and whose talismanic use is not based on chemical composition.
text: It is an amorphous material known as a “mineraloid.