Assertion: granite's mineral | /r/HasProperty | quartz
Facets:
Source sentences:
text: Its three main minerals are feldspar, quartz, and mica, which occur as silvery muscovite or dark biotite or both.
text: that is, a rock that was originally formed when lava or magma cooled—and while its composition can vary widely, most versions have two primary minerals: quartz (20 to 60 percent) and feldspar (about 35 percent).