Obsidian is a naturally created glass. It is formed form volcanic lava which cooled too quickly for significant crystallization to occur. Obsidian is a very powerful stone that reminds us that birth and death are one with the other. This is a stone that has always been associated with guardian spirits that watch over us, and is connected to protection on all levels. Obsidian makes a strong shield of protection around the wearer. It is an excellent grounding stone as it helps to release negativity.