Black Obsidian Phoenix Skull
Metaphysically, Obsidian is called The Stone of Transition. It is an excellent stone for dispelling negativity. It has powerful grounding energy which can be very beneficial at specific times in one's life. Obsidian is known for its ability to increase one's immune system and bring about good luck. It has an amazing mirror-like ability that projects back to us and image of our true selves.
By affording us this objective view, Obsidian enables us to determine which aspects of the self we should work on to improve, as well as showing us the aspects that have been outgrown and are best abandoned in order to make room for growth.
It vibrates to the number 3 and is associated with Sagittarius.