Assertion: thorium | /r/HasProperty | refined as a by-product
Facets:
value: chiefly
type: DEGREE
value: from monazite sands
type: LOCATION
Source sentences:
text: Thorium is estimated to be about three to four times more abundant than uranium in the Earth's crust, and is chiefly refined from monazite sands as a by-product of extracting rare earth metals.