Obsidian, also known as "Dragon Crystal" and "Ten Victory Stone", is a common amorphous gem and volcanic crystal. Obsidian is a natural colored glass formed by the sudden cooling of magma from volcanic lava. It is an amorphous gem, and its main component is silicon dioxide, usually black. Obsidian has the characteristics of glass, and its cross section is shell-shaped and very sharp. At present, most obsidian jewelry is produced in Central America and North America, and the national stone of Mexico is obsidian. Obsidian is also produced in China and Tibet. Obsidian has been used as an evil spirit and amulet since ancient times. Can be processed into handicrafts.