These differences help define and explain how the earth works. Not only is it my personal favorite, it is without a doubt the most common rock type on the continental land masses. Yosemite Valley in the Sierra Nevada and Mt. Rushmore are two notable examples of granitic rocks. Granite is intrusive, which means that the magma was trapped deep in the crust , and probably took a very long time to cool down enough to crystallize into solid rock. This allows the minerals which form plenty of time to grow, and results in a coarse-textured rock in which individual mineral grains are easily visible.
Granite is the ultimate silicate rock.
Relatively small amounts of iron and magnesium occur, but since they have generally higher densities it's not surprising that there isn't very much in the granite. Due to the process of differentiation , most of the heavier elements are moving towards the core of the earth, allowing the silica and oxygen to accumulate on the surface. And accumulate it has. We call this purified material felsic because of the relatively high percentage of silica and oxygen. Basalt is extrusive.