Obsidian is a result of volcanic molten lava cooling so fast it did not have time to crystalize, so it is a form of natural glass. Thus, energetically it works very quickly and powerfully. Like a mirror, nothing can be hidden, so all is revealed including things one might not want to look at. As such it is a force for catharsis and growth by promoting compassion & strength. At the same time, Obsidian provides protection, grounding, and calming effects to heal from trauma, especially for sensitive people. It repels negativity and channels power into good.
Use a carving in your living space, or spiritual meditations for spiritual growth, and insight to be activated. They combine wonderfully with other crystals that you are using. Feel free to combine different sizes and types of carving pieces together to make powerful healing and spirit-filled grid.