Sandstone relief also called sand rock, sandstone relief from the mineral silica particle agglomerates crystalline form. The sandstone relief silica soil is formed by the addition of calcium carbonate and iron oxide, which is a long time and the strength, and the hardness of the sandstone in some areas is even more than that of granite. Because of the large size of the particles, the sandstone relief is hard, and it is suitable for large outdoor stone works.