Obsidian beads are a naturally occurring volcanic glass formed when lava cools very rapidly without crystal growth or fusion. The result is that obsidian becomes glass, but retains its shape and texture. Obsidian is hard, brittle, and breaks conchoidally. It comes in many colors including white, pale yellow, green and brown. Because of its unique colors obsidian is found in almost every known culture and used as far back as 8000 BC. Its sharpness, natural beauty, and hardness make it a material that historically was highly valued by ancient cultures around the world.