Obsidian is a type of pitchstone.   It is volcanic glass and is smokey brown to shiny black. It is formed when magma cools very quickly.   Obsidian was valued by early peoples and was used to shape arrowheads, crude knives, spear points and other cutting tools.  Obsidian was and is used today to make jewelry.  One type of Obsidian that is found in the southwestern United States is call Apache Tears and is a favorite for making jewelry.

       Obsidian is found world wide but in the United States it is found in Yellowstone Park, California, Oregon, Utah, New Mexico, and Hawaii.