Assertion: basalt's feldspar | /r/MadeOf | alkali feldspar
Facets:
Source sentences:
text: Strictly speaking, granite is an igneous rock with between 20% and 60% quartz by volume, and at least 35% of the total feldspar consisting of alkali feldspar, although commonly the term "granite" is used to refer to a wider range of coarse-grained igneous rocks containing quartz and feldspar.