Describes magma or igneous rock that is rich in feldspars and silica and that is generally light in color.

Describes magma or igneous rock that is rich in feldspars and silica and that is generally light in color.

• A. Felsic
• B. Mafic
• C. Ultramafic
• D. Intermediate

Answer: (A)

Felsic describes magma or igneous rocks that are rich in silica and light-colored minerals, especially feldspars and quartz. That high silica content and presence of light minerals give these rocks their characteristic pale color. This is the defining contrast with other rock types: mafic rocks have more dark, magnesium- and iron-rich minerals and look dark; ultramafic rocks are even richer in those dark minerals and are very dark; intermediate rocks sit somewhere in between. Common felsic rocks include granite and rhyolite, which form from magma that crystallizes into light-colored minerals.

Felsic describes magma or igneous rocks that are rich in silica and light-colored minerals, especially feldspars and quartz. That high silica content and presence of light minerals give these rocks their characteristic pale color. This is the defining contrast with other rock types: mafic rocks have more dark, magnesium- and iron-rich minerals and look dark; ultramafic rocks are even richer in those dark minerals and are very dark; intermediate rocks sit somewhere in between. Common felsic rocks include granite and rhyolite, which form from magma that crystallizes into light-colored minerals.