These rocks are classified based on their silicon content as felsic or mafic.
The grains of this kind of rock are classified based on whether they are phaneritic (fan-er-it-ick) or aphaneritic (eh-fan-er-it-ick) based on crystal size and visibility. These rocks are classified based on their silicon content as felsic or mafic. Formations with large amounts of exposed rock of this type are called batholiths, and usually form when sedimentary rocks have eroded from around instrusive formations. Often expelled via pyroclastic flow, the most notable rocks of this kind are granite and basalt. For 10 points, name this type of rock made from cooled magma.
The grains of this kind of rock are classified based on whether they are phaneritic (fan-er-it-ick) or aphaneritic (eh-fan-er-it-ick) based on crystal size and visibility.
{igneous} rock