The composition of gobi jade in Xinjiang is sio2 _ 2, which is quartzite with hardness of 7.0 and density of 2.65. As much as 40% of the time is released on the earth, so silica is widely distributed. In fact, it is a component with glass. Jewelry-grade products are divided into three grades, the first is crystalline crystal, the second is invisible crystalline agate, and the third is invisible crystalline chalcedony. Gobi jade is chalcedony. Other minerals are easy to penetrate, rich in color, high in hardness, low in density and brittle because of their low density. Jewelry. Most of them are used as accessories of real jade, as chains and so on. The domestic producing areas are Altay in Xinjiang, Ili in Karamay, Huang Longyu in Yunnan, chalcedony in Shaanxi, lantian jade and Bahrain Frozen in Inner Mongolia. There are Bayu in Afghanistan and chalcedony in Canada abroad, which are widely distributed, so I won't list them one by one. Even agate is inexhaustible, let alone chalcedony.