Blue Obsidian is a naturally created glass. This one is blue to teal green. It is formed from volcanic lava which cooled too quickly for significant crystallization to occur. It is colored by the presence of minerals present during formation.This is a stone/glass that has been associated with spirit fire and guardian spirits that watch over us, Blue obsidian also has influenences from the mother goddess, water, mystery and ancesters. Sold by aproximate weight - not stone size or count.