Assertion: silica | /r/AtLocation | crystalline minerals
Facets:
value: in all land areas
type: LOCATION
Source sentences:
text: Subscribe today In compounds, silicon dioxide occurs both in crystalline minerals (e.g., quartz, cristobalite, tridymite) and amorphous or seemingly amorphous minerals (e.g., agate, opal, chalcedony) in all land areas.