The deep black color of Jet makes it a popular skull medium, though it can also be found in dark brown hues. Jet is a variety of Coal known as 'lignite'. It is often used by healers and shaman to channel the earth spirits and purify. Jet is also considered to be one of the most powerful of all protection stones, as it can quickly neutralize all negative energies in a room. Healing of the liver and kidneys is also attributed to Jet.