Metamorphic stone quartzite is formed when sandstone occurs naturally. The crystals have been welded together by millennia of exposure to intense heat and pressure beneath the earth's crust, making this stone very hard—the ideal material for your kitchen countertop. Because of their similar names, quartzite and quartz are commonly misunderstood, so keep that in mind when shopping. But, thanks to modern manufacturing techniques, quartz countertops can be produced to resemble any natural stone, even quartzite. But natural quartzite is the real natural stone and formed by nature and not in manufacturing facilities like quartz.