Most dark-colored igneous rocks have a high density.
Most dark-colored igneous rocks are mafic, which means they are rich in minerals like pyroxene, olivine, and amphibole. These minerals give the rocks their dark color due to higher iron and magnesium content. Additionally, dark-colored igneous rocks are typically extrusive, forming from rapid cooling at the Earth's surface.
Felsic rocks are light-colored igneous rocks rich in aluminum, potassium, silicon, and sodium. Examples include granite and rhyolite.
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.
Light colored igneous rocks are part of the felsic family. These rocks are rich in silica and aluminum minerals, giving them their light color. Examples include granite and rhyolite.
The dark colored mica is called biotite. It is a common mineral found in igneous and metamorphic rocks and is known for its dark brown to black color.
Most dark-colored igneous rocks are mafic, which means they are rich in minerals like pyroxene, olivine, and amphibole. These minerals give the rocks their dark color due to higher iron and magnesium content. Additionally, dark-colored igneous rocks are typically extrusive, forming from rapid cooling at the Earth's surface.
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.
less dense
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.
Light colored
igneous
Dark colored rocks.
Igneous rocks that are medium colored and have no silica are called mafic rocks. They are mainly composed of magnesium and iron.
Dense. Light colored igneous rocks have lower density compared to dark colored igneous rocks due to their higher silica content, which results in slower cooling and the formation of larger crystals.
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.
granitic igneous rocks are light colored because of a lower density than basaltic rocks
Felsic rocks are light-colored igneous rocks rich in aluminum, potassium, silicon, and sodium. Examples include granite and rhyolite.