1, rocks through long-term natural aging, organizational structure is even a very small linear expansion coefficient, internal stress disappear, not deformed. 2, rigid, high hardness, wear resistance, and temperature of deformation. 3, are not afraid of acid, alkali material erosion, will not rust, anti-magnetic, insulating, not coated with oil, easy to stick dust, maintenance, easy and convenient, long service life. 4, will not scratch, without a constant temperature to prevent, at room temperature, can maintain its original physical properties. 5, no magnetization measurements can move smoothly, without Zhise sense, free from damp impact, the plane that set good. Physical properties: the proportion of 2970-3070kg/m3 compressive strength :2500-2600kg / cm3 elasticity :1.3-1 .5 × 106kg/cm2 water absorption. Decorative stone for a processed product, its quality can be used to identify the following four aspects: a concept that the surface of the stone structure of the naked eye. In general, the uniform structure of fine material with a delicate texture of stone, the stone of the share; ranging from coarse grain structure of the stone and its appearance is poor. In addition, the stone due to geological effects of which often have some minor cracks in the stone most likely to rupture along the these areas, attention should be removed. As for the lack of more angular appearance, the choice should be noted in particular. The second volume, that is, the amount of stone sizes, so as not to affect splicing, or cause splicing patterns, patterns, lines, deformation, affecting the decorative effect. Three, that is to listen to Stone's percussion sounds. In general, good quality stone of its clear and melodious sound of percussion; the contrary, if there is a slight crack or the internal stone weathering caused by loose particles indirectly thixotropic, the percussion sound gruff. Fourth test, which uses a simple test method to test the quality of the stone is good or bad. Usually drops on the back of a stone ink pellets, such as leaching of the ink to disperse quickly, which shows that particles loose stone or the existence of internal cracks, the stone of poor quality; the other hand, if the ink droplets are standing still, then a good texture of stone.