High quality sandstone, very compact structure, even harder than granite. In durability, sandstone can be compared with marble, granite. Many of the buildings made of sandstone one or two hundred years ago still have their charm. The sand and stone particles are uniform, fine texture, loose structure, so the water absorption rate is high (high cost in protection), with sound insulation, moisture absorption, damage resistance, weathering resistance, fading resistance, water does not melt, no radioactivity and so on.
