Obsidian rock forms from molten lava that cooled very quickly and had no time to form into glass. This stone has powerful metaphysical properties that helps to shield against negativity. The energy of these stones helps call to action the cutting of ties, and breaking negative attachments to people with whom you have been close. 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.