Obsidian is formed when volcanic lava cools quickly. Depending on the presence of minerals and air bubbles in the cooling process, the stone may remain in its pure Black Obsidian state, show its red iron in Mahogany Obsidian, brilliant colors in Rainbow Obsidian, gold and silver in Sheen Obsidian or gray crystallites in Snowflake Obsidian. All forms of Obsidian are used for transmuting negative energy to positive vibrations, thus protecting the aura from unwanted energies. Obsidian healing crystals also aid with grief and help us to overcome bad habits and obsessions.