Assertion: cassiterite | /r/HasProperty | primary source of tin
Facets:
value: throughout history
type: TEMPORAL
Source sentences:
text: Cassiterite is a primary source of tin.
text: Cassiterite is a primary of tin.
text: The main source of tin is cassiterite (SnO2), a tin oxide mineral; cassiterite has been the primary source of tin throughout history.