Which type of igneous rock has a higher silica concentration?

The most common igneous compositions can be summarized in three words: mafic (basaltic), intermediate (andesitic), and felsic (granitic). Felsic composition is higher in silica (SiO2) and low in iron (Fe) and magnesium (Mg). Mafic composition is higher in iron and magnesium and lower in silica.

What is silica in igneous rocks?

Silica (SiO2) content also controls the minerals that crystallise and is used to further classify igneous rocks as follows: Acid: rocks with above 63\% silica (mostly feldspar minerals and quartz), e.g. granite.

Is silica igneous?

Of the oxides, silica (SiO2) is usually the most abundant. Because of this abundance and because most igneous minerals are silicates, silica content was used as a basis of early classifications; it remains widely accepted today.

How do you identify igneous rocks?

Igneous rocks can be distinguished from sedimentary rocks by the lack of beds, lack of fossils, and lack of rounded grains in igneous rocks, and the presence of igneous textures.

How does the amount silica affect the color of igneous rock?

The more silica you have in a rock, the paler it tends to be. Felsic rocks have high silica content, because they contain lots of quartz and another mineral called feldspar.

What characteristics are used to identify igneous rocks?

Two main characteristics are used to classify igneous rocks: 1) texture (the size of the mineral grains in the rock; and 2) composition (often determined by what the actual minerals are).

How does silica affect igneous rocks?

The more silica you have in a rock, the paler it tends to be. Felsic rocks have high silica content, because they contain lots of quartz and another mineral called feldspar. Consider mafic rocks, which have low silica content and tend to be dominated by coloured minerals like olivine and micas.