Assertion: obsidian | /r/HasProperty | semiprecious stone
Facets:
value: in mesoamerica
type: LOCATION
value: because of its physical characteristics
type: CAUSE
Source sentences:
text: In Mesoamerica, obsidian was considered a semiprecious stone because of its physical characteristics that produced a hard sharp edge used for cutting tools, rituals, and military weapons which were centralized and manufactured in Teotihuacan for mass production.