irror, mirror, on the wall, who is the most mindful of them all? With a Black Obsidian stone in hand, it’s probably you. Black obsidian has long been toted for its metaphysical abilities, and historically significant uses. This structureless rock is also known as volcanic glass because of its smooth, reflective luster. This stone forms when volcanic lava cools too rapidly to form crystalline structures. In the Stone Age, civilizations around the world used black obsidian stone to create arrowheads, spears and cutting tools. While still used as a cutting tool in some modern day industries, obsidian is more useful on a personal level when trying to emotionally slice away negative energy.