Granite is an igneous rock formed from the slow crystallization of magma below Earth’s surface. It’s mainly composed of quartz (40-60%) along with alkali feldspars, plagioclase feldspars, and other mineral impurities present during its formation. It ranks 6 on the Mohs mineral hardness scale. Because granite is highly durable and stain-resistant, granite countertops are a popular choice in the kitchen. Regular sealing is required though to close up its naturally porous surface.