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How do light colored rocks and dark colored rocks differ in composition?
Wiki User
∙ 14y 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
Light colored rocks generally contain more silica and feldspar minerals, which give them their light color. Dark colored rocks tend to have more iron and magnesium-rich minerals, such as olivine and pyroxene, which contribute to their dark color. The differences in mineral composition result in contrasting physical and chemical properties between light and dark rocks.
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
∙ 14y 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 are granitic igneous rocks light in color?
granitic igneous rocks are light colored because of a lower density than basaltic rocks
Why do rocks sometimes have different colored specks and different markings?
Rocks can have different colored specks and markings due to the presence of various minerals within them. These minerals can form under different conditions and can give the rocks their distinct colors and patterns. Factors such as the composition of the original rock, the presence of other elements, and the pressure and temperature conditions during formation all play a role in determining the appearance of 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 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 with a lower density than basaltic rocks?
Felsic rocks like granite are light-colored igneous rocks with a lower density than basaltic rocks due to their silica-rich composition. Their lower density is a result of having a higher proportion of quartz and feldspar minerals, which are lighter than the minerals found in basalt.
Light-colored igneous rocks are less what than dark-colored igneous rocks are?
less dense
What are light colored often intrusive igneous rocks containing a high percentage of silica called?
Light colored often intrusive igneous rocks containing a high percentage of silica are typically called granitic rocks. They are commonly found in continental crust and have a composition similar to granite, containing minerals like quartz, feldspar, and mica.
In what ways do rocks differ?
Rocks can differ in their composition, texture, and origin. Composition refers to the minerals present in the rock. Texture refers to the size, shape, and arrangement of mineral grains within the rock. Origin refers to how the rock was formed, whether it was through cooling of magma, cementing of sediments, or alteration of existing rocks.
Why are dark colored igneous rocks heavier than light colored ones?
As a first approximation, the colour of igneous rocks gives an estimate of the concentration of iron in it. Very dark igneous rocks commonly a large fraction of minerals with iron as a major constituent. As those minerals are denser than most other silicate minerals occuring in igneous rocks, dark colored igenous rocks are usually denser than the ligher ones.
Basaltic igneous rocks are?
Light colored
Why are some igneous rock dark and other light?
The color of igneous rocks is determined by their mineral composition. Dark-colored igneous rocks, like basalt, contain minerals that are rich in iron and magnesium, which give them their dark appearance. Light-colored igneous rocks, like granite, tend to have higher concentrations of quartz and feldspar minerals, which are lighter in color. Overall, the mineral content and composition of the rock influence its color.
Light-colored igneous rocks that are rich in aluminum potassium silicon and sodium are called what rocks?
Felsic rocks are light-colored igneous rocks rich in aluminum, potassium, silicon, and sodium. Examples include granite and rhyolite.
