Obsidian is a naturally occurring volcanic glass formed when lava cools rapidly. It has a smooth, shiny surface and is typically black or dark green in color. Obsidian can be found in various locations around the world, including the United States, Mexico, and Japan.
Obsidian has been used by humans for thousands of years to make tools, weapons, and jewelry. It is a very sharp material and can be used to create a variety of different objects. Obsidian was also used by the ancient Egyptians to create mirrors and other reflective surfaces.