Mafic Vs. Felsic - The Difference Between Mafic and Felsic
Felsic and mafic rocks are two main types of igneous rocks, which are rocks that are formed from the cooling and solidification of magma or lava. Felsic rocks are high in silica (SiO2), while mafic rocks are low in silica. This difference in silica content gives the two types of rocks different physical and chemical properties.
![]() |
Mafic Vs. Felsic Rocks: The Difference Between Mafic and Felsic |
Felsic Rocks
Felsic rocks are typically light in color, such as white, pink, or gray. They are also relatively low in density and have high melting points. Felsic rocks are composed of minerals such as quartz, feldspar, and mica.
Mafic Rocks
Mafic rocks, on the other hand, are typically dark in color, such as black or green. They are also relatively dense and have low melting points. Mafic rocks are composed of minerals such as olivine, pyroxene, and amphibole.
Formation of Felsic and Mafic Rocks
Felsic rocks are formed from the cooling and crystallization of felsic magma, which is relatively rich in the lighter elements silicon, oxygen, aluminum, sodium, and potassium. Felsic magma is less dense and more viscous than mafic magma, so it rises more slowly through the Earth's crust. When it reaches the surface, it can either cool and crystallize into extrusive felsic rocks like rhyolite and obsidian, or it can intrude into the surrounding rock and cool slowly to form intrusive felsic rocks like granite and pegmatite.
Mafic rocks are formed from the cooling and crystallization of mafic magma, which is relatively rich in the heavier elements magnesium and iron. Mafic magma is more dense and less viscous than felsic magma, so it rises more quickly through the Earth's crust. When it reaches the surface, it can either cool and crystallize into extrusive mafic rocks like basalt and scoria, or it can intrude into the surrounding rock and cool slowly to form intrusive mafic rocks like gabbro and dolerite.
Mineral Composition of Mafic and Felsic Rocks
Mafic rocks are dark in color and have a high density. They are typically composed of the following minerals:- Olivine
- Pyroxene
- Amphibole
- Mica
- Plagioclase feldspar
- Quartz
- K-feldspar
- Plagioclase feldspar
- Mica
![]() |
Classification diagram for igneous rocks |
Examples of Felsic and Mafic Rocks
Some examples of felsic rocks include:
- Granite
- Rhyolite
- Obsidian
- Pegmatite
- Pumice
Some examples of mafic rocks include:
- Basalt
- Gabbro
- Diabase
- Peridotite
- Scoria
Felsic and mafic rocks are two important types of igneous rocks. Their different physical and chemical properties are due to their different silica contents. Felsic rocks are high in silica, while mafic rocks are low in silica.
See also:
General Classification of Igneous Rocks
How to Classify Igneous Rocks Into (Ultramafic, Mafic, Intermediate and Felsic)?