Black Tourmaline Or Black Obsidian.

In metaphysical practices, dark or black spheres are desired for their grounding, protecting and blocking qualities. Practitioners believe they are of the earth and act as an energetic shields, absorbing or repelling negative energies, stress, and environmental pollution.

Emotionally, they are thought to reveal hidden emotional truths, regrets, traumas, or blockages to the surface so that they can be acknowledged and released.