Assertion: cerium | /r/HasProperty | compatible element
Facets:
value: in zircon
type: LOCATION
value: in silica
type: LOCATION
value: at 4
type: TEMPORAL
Source sentences:
text: Cerium can occur in nature as a 3+ or 4+ ion and is a compatible element (at 4+ valency) in zircon and less commonly in silica.