Limestone is a kind of stone material which is non-radiative, non-toxic, high-quality, odorless and impervious. It is called an environmental-friendly product within the stone industry. Limestone is easy to be customized into limestone slabs in various specifications. It has been widely used in indoor and outdoor decoration, or used as paving stones for large squares. There are mainly blue limestone and beige limestone in our country. Limestone can be used as outdoor paving stones, stepping stones, stairs, and can also be used to make various sculptures.