Granite is an intrusive igneous rock, which means that it is formed through the cooling of molten rock. It forms deep underground, and is made up of quartz, feldspar, micas, amphiboles, and a mixture of additional trace minerals. The fact that it is made up of so many minerals is what gives each piece of granite it’s unique patterned appearance. Generally, the slower the rock cooled as it was forming, the larger the mineral crystals that form within it.