There are three major compositional groups of igneous rocks, mafic, felsic, and intermediate.
Mafic
The mafic igneous rocks are rich in magnesium and iron, making them a portmaneau of magnesium and ferric. They tend to be with dark coloration, with biotite and olivine being one of those rocks.
Felsic
The feslic igneous rocks are rich in elements that are forming the feldspar and quartz. Their coloration is lighter, and they come in numerous colors, with the granite and quartz being one of them.
Intermediate
The intermediate igneous rocks are in a way transitional rocks between the mafic and the felsic ones. They have a mixture of both mafic and felsic minerlas. Their coloration varies, and the andesite and dacite are some of them.
