Natural stone is made up of several different minerals,each having different degrees of hardness. Some of the softer or flakier minerals on the surface are removed during the polishing process, causing pits. These pits do not make the stone less durable or inferior. As a natural product, the slab may contain naturally occurringimperfections.These characteristics, including color variations, irregular markings, fissure lines (which appear as hairline cracks), and polishing swirls all add to the beauty and rugged elegance that is normal with natural stone.