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How do light colored rocks and dark colored rocks differ in composition?
Wiki User
∙ 13y ago
Light colored igneous rock is called felsic, and is high in quartz, muscovite mica, and orthoclase feldsparcontent. Dark colored igneous rock is called mafic, and contains a lesser amount of silica along with olivine, pyroxene, amphibole, biotite mica, and plagioclase feldspar.
Wiki User
∙ 16y ago
Wiki User
∙ 12y agoLight coloured igneous rocks (felsic) tend to have greater silica and aluminum content and a lower iron and magnesium content than dark (mafic) rocks.
The common mafic rock forming minerals tend to be the following:
- Olivine (Mg, Fe)2SiO4
- Pyroxene - Orthopyroxenes (Mg,Fe)2Si2O6 and Clinopyroxenes Ca(Mg,Fe)Si2O6
- Amphibole
- Biotite mica - (K(Mg,Fe)3AlSi3O10(F,OH)2)
- Plagioclase feldspars (Ca,Na)AlSi3O8
Common felsic rock forming minerals include:
- Quartz - SiO2
- Muscovite mica - KAl2(AlSi3O10)(F,OH)2
- Orthoclase feldspars - KAlSi3O8
Wiki User
∙ 13y agoA light colored igneous rock is more less dense and more felsic (which means the rock is mostly rich in silicon and aluminum). A dark colored igneous rock is more dense and mafic (which means the rocks are rich in iron and magnesium.
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Does Light-colored rocks with lower densities form from basaltic magma?
Basaltic Magmas are dark colored, heavy and are ferromagnesian in composition, so they most times do not form light colored rocks, rather, the Felsic Granitic Magma forms the light colored rocks with lower densities.
In general how does the density of a light colored igneous rock differ from that of a dark colored igneous rock?
Light-coloured igneous rocks, such as granite, have a higher silica content and lower iron and magnesium than darker ones, such as basalt. Since iron and magnesium are very dense minerals, this makes darker igneous rocks more dense than lighter ones.
Why do rocks sometimes have different colored specks and different markings?
they have differ minerals
Why are granitic igneous rocks light in color?
granitic igneous rocks are light colored because of a lower density than basaltic rocks
Is it true that magma that is low in silica usually forms light colored rocks?
Magma doesn't produce lava. Magma is lava. Magma is called magma when it is under the ground but when it is released via a volcano it is called lava when it is above ground. The magma or lava can produce dark to light color rocks after it cools depending on the composition of the magma or lava. There is also a range in the color of the lava depending on it composition and temperature also.
How does the density of a light colored rock differ from the density of dark colored rock?
Normally, light colored igneous rocks are less dense compared to dark colored igneous rocks. This is because the light colored rocks have a less iron in them.
How does the density of a light colored igneous rock differ from that of a dark colored igneous rock?
Normally, light colored igneous rocks are less dense compared to dark colored igneous rocks. This is because the light colored rocks have a less iron in them.
Does Light-colored rocks with lower densities form from basaltic magma?
Basaltic Magmas are dark colored, heavy and are ferromagnesian in composition, so they most times do not form light colored rocks, rather, the Felsic Granitic Magma forms the light colored rocks with lower densities.
In what ways do rocks differ?
Rocks differ from their textures, hardness, colour, composition and shapes.
In general how does the density of a light colored igneous rock differ from that of a dark colored igneous rock?
Light-coloured igneous rocks, such as granite, have a higher silica content and lower iron and magnesium than darker ones, such as basalt. Since iron and magnesium are very dense minerals, this makes darker igneous rocks more dense than lighter ones.
Light-colored igneous rocks are less what than dark-colored igneous rocks are?
less dense
Basaltic igneous rocks are?
Light colored
Why do rocks sometimes have different colored specks and different markings?
they have differ minerals
Why are granitic igneous rocks light in color?
granitic igneous rocks are light colored because of a lower density than basaltic rocks
Is it true that magma that is low in silica usually forms light colored rocks?
Magma doesn't produce lava. Magma is lava. Magma is called magma when it is under the ground but when it is released via a volcano it is called lava when it is above ground. The magma or lava can produce dark to light color rocks after it cools depending on the composition of the magma or lava. There is also a range in the color of the lava depending on it composition and temperature also.
Would you expect extrusive rocks produced by an explosion volcano to be light or dark in color?
The color of igneous rocks is tied to their composition. Rocks (minerals) that have a high concentration of Fe, Mg and Ca, tend to be darker colored than those that are rich in Al, Si, and K. So, the volcanic rocks like rhyolite are light in color due to their composition. However, there are many volcanic rocks, like andesites, that are a bit darker, and those form from explosive volcanoes like the Cascade volcanoes of western North America.
Light colored igneous rocks are part of what family?
The felsic family.
