Assertion: alumina | /r/AtLocation | nature
Facets:
Source sentences:
text: Aluminum oxide (uh-LOO-min-um OK-side) is white crystalline powder that occurs in nature in a variety of minerals, including boehmite, bayerite, corundum, diaspore, and gibbsite.
text: Aluminum oxide occurs in nature as various minerals such as bauxite or corundum.