Black Obsidian Stone is a powerful cleanser of psychic smog from your aura. It's a strong psychic protection stone that helps shield you against negativity. It has powerful metaphysical properties and a good action to cut or sever ties. This will help to break negative attachments to people with whom you have been close. The energy of these stones may stimulate the gift of prophecy and may boost precognition. Pieces of these stones that had a shiny surface were used in the past as a tool for scrying. It an excellent crystal to use when you have been doing spiritual or healing work, as it has a strong action to ground you to Mother Gaia.