The appearance of the crystal: The shape of the outer crystal which in turn reverses the internal arrangement of the constituent atoms. Color: A certain number of metals that have distinct colors such as green or yellow can be distinguished and seen with the naked eye on the outside of the metal. Abrasion: After rubbing the metal by the abrasion board produces a certain powder in a certain color. Abrasion is the color of the metal powder after rubbing, and is used to distinguish similar metals in color. Roughness: a property that expresses the metal's resistance to scratching and can be determined by the use of a known hardness metal and scratching it. Luminosity: It reflects the brightness of the surface of the metal through the intensity of light reflected from its surface, and is either a metallic luster, or semi-metallic luster, or non-metallic luster. Transparency: It expresses the ability of the metal to pass light through it, and the metals are divided accordingly into opaque metal, semi-transparent metal and transparent metal. Specific weight: This refiner expresses the density of the metal relative to the density of water. Schizophrenia is the susceptibility of the metal to cracking. This cracking occurs on surfaces with weak chemical bonds. Volume 0%