Granite, one of the main rocks in the earth's crust, is an igneous rock formed by the condensation of magma beneath the earth's surface. The main components are feldspar and quartz. The etymology of granite is Latin granum, meaning grain or granule. Because granite is a plutonic rock, often can form well-developed, naked eye discernible mineral particles, hence the name. Granite is a deep-seated acidic igneous rock formed by the condensation of magma in the deep underground. Some granites are gneisses or migmatized rocks formed by metamorphism of magma and sedimentary rocks. Granite consists mainly of feldspar, quartz, black and white mica, and quartz content is 10% to 50%. The content of feldspar is about 2/3 of the total, which is divided into orthoclase, plagioclase (alkali lime) and microcline (potassium alkali). The mineral compositions of different varieties are not the same, but also contain pyroxene and hornblende.