Felsic rocks are rich in quartz and feldspar due to high silica content.

• A. True
• B. False
• C. Mostly dark minerals
• D. Mostly heavy minerals

Answer: (A)

Felsic rocks are characterized by high silica content, which favors the formation of quartz and feldspar as the dominant minerals. Quartz is pure silica, and feldspars are aluminum silicates that crystallize from silica-rich magmas, so these rocks accumulate lots of these minerals. That combination gives felsic rocks their light color and relatively low density compared to rocks with more mafic (dark) minerals like pyroxene or olivine. So the statement is true because high silica content directly leads to quartz and feldspar being the primary minerals in felsic rocks. Rocks that are mostly dark minerals are mafic, and “mostly heavy minerals” isn’t a defining trait of felsic igneous rocks.