Natural stone products could have some natural variations, fossils, Calcite, mineral veins ...etc. And those natural veins can cause some hair cracks. Some times not easy to recognize them and they could become bigger during the transport process. Because of that natural ingredients, we recommend adding 10% extra to your needed quantity of natural stones. That %10 will give you enough options for the cutting edges and natural selections. (The recommended additional % is 5 extra for the porcelain tiles.)