Assertion: tungsten | /r/HasProperty | found as wolframite
Facets:
value: always
type: DEGREE
Source sentences:
text: Tungsten does not occur naturally in its pure metallic state but is always found as an ore such as wolframite or scheelite.
text: Tungsten is found in certain minerals including wolframite ((Fe, Mn)WO 4 ) and scheelite (CaWO 4 ).