We find ourselves reccommending Black Tourmaline to pretty much everyone! Definitely the preeminent stone of protection, this crystal offers a powerful energetic barrier between us and outside negative energies. An extremely strong stone for grounding, this is a great stone for stabilizing our energies. If you have to be in a negative environment for prolonged periods of time we highly reccommend to carry this crystal with you and excellent for use after a stressful day. Also extremely effective for combatting EMF waves produced by our cellphones, computers, radio waves and all types of electromagnetic junk. 
Resonates with Root chakra.

Crystals shown in picture are average pieces of what one should expect to receive, we will always hand select the best ones available for you!