Assertion: hafnium | /r/AtLocation | trace amount
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: Due to chemical properties of the two elements, namely their valences and ionic radii, Lu is usually found in trace amount in rare-earth element loving minerals, such as garnet and phosphates, while Hf is usually found in trace amount in zirconium-rich minerals, such as zircon, baddeleyite and zirkelite.