<P> About 64.7 % of the Earth 's crust by volume consists of igneous rocks ; making it the most plentiful category . Of these , 66 % are basalts and gabbros , 16 % are granite , and 17 % granodiorites and diorites . Only 0.6 % are syenites and 0.3 % peridotites and dunites . The oceanic crust is 99 % basalt , which is an igneous rock of mafic composition . Granites and similar rocks , known as meta - granitoids , form much of the continental crust . Over 700 types of igneous rocks have been described , most of them having formed beneath the surface of Earth 's crust . These have diverse properties , depending on their composition and the temperature and pressure conditions in which they were formed . </P>
<P> About 64.7 % of the Earth 's crust by volume consists of igneous rocks ; making it the most plentiful category . Of these , 66 % are basalts and gabbros , 16 % are granite , and 17 % granodiorites and diorites . Only 0.6 % are syenites and 0.3 % peridotites and dunites . The oceanic crust is 99 % basalt , which is an igneous rock of mafic composition . Granites and similar rocks , known as meta - granitoids , form much of the continental crust . Over 700 types of igneous rocks have been described , most of them having formed beneath the surface of Earth 's crust . These have diverse properties , depending on their composition and the temperature and pressure conditions in which they were formed . </P>
the most common type of rock in earth 's crust is
the most common type of rock in earth 's crust is
igneous
igneous