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Granite is a course-crystalline felsic intrusive rock. The presence of quartz is a good indicator of granite. Granite commonly has large amounts of salmon pink potassium feldspar and white plagioclase crystals that have visible cleavage planes.
Granite (/ ˈɡrænɪt / GRAN-it) is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground.
Granite is the name given to intrusive felsic rocks, whereas rhyolite is the name given to extrusive felsic rocks. Felsic rocks are produced primarily in convergent plate boundaries in which an oceanic plate is subducting beneath either another oceanic plate (such as in Japan) or a continental plate (such as along the Andes Mountains of South ...
For example, a felsic intrusive rock is called granite, whereas a felsic extrusive rock is called rhyolite. Granite and rhyolite have the same mineral composition, but their grain size gives each a distinct appearance.
How Do We Know Granite Is Felsic? To test the surety of its nature, we will discuss the chemical and physical properties of granite and then match them with the properties of felsic and mafic substances.
Compilations of many rock analyses show that rhyolite and granite are felsic, with an average silica content of about 72 percent; syenite, diorite, and monzonite are intermediate, with an average silica content of 59 percent; gabbro and basalt are mafic, with an average silica content of 48 percent; and peridotite is an ultramafic rock, with an ...
Granite is a felsic rock. Its mineral composition is predominantly alkali feldspar, quartz, and plagioclase, with minor amounts of hornblende (amphiboles) and biotite (mica). Also, depending on the variety, it may have muscovite, riebeckite, aegirine, aegirine-augite, arfvedsonite, ferroan augite, orthopyroxene, iron-rich olivine, etc.
Felsic magmas and lavas have lower temperatures of melting and solidification than mafic magmas and lavas. Felsic rocks are usually light in color and have specific gravities less than 3. The most common felsic rock is granite. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars (albite-rich).
A felsic intrusive rock is called granite, whereas a felsic extrusive rock is called rhyolite. Granite and rhyolite have the same mineral composition, but their grain size gives each a distinct appearance.
ADVERTISEMENT. What is Granite? Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth's surface. Granite is composed mainly of quartz and feldspar with minor amounts of mica, amphiboles, and other minerals.