Granite is a felsic intrusive igneous rock consisting primarily of quartz, potassium feldspar (e.g., orthoclase or microcline) or plagioclase feldspar (albite, or labradorite), mica (e.g., muscovite or biotite), and amphiboles (e.g., hornblende). Granites make up much of the intrusive mass of continental crust forming huge plutons (e.g. batholiths or lacoliths) that may be over 100 miles in diameter. Pikes Peak is part of a large granite batholith. Granite is often used for construction due to its durability and chemical resistance.