Granite

"A very hard, crystalline, igneous rock, gray to pink in color, composed of feldspar, quartz, and lesser amounts of dark ferromagnesian materials"

Granite is an igneous rock that is composed primarily of four minerals: quartz, feldspar, mica, and usually hornblende. Granite is formed from magma cooling very slowly, deep under the surface of the Earth. Depending on its location, the composition will vary, which is the ultimate reason for many different colors and patterns.