Black Tourmaline is brilliant for grounding, probably one of the best! It's also one of the best protective stones against negative energy (people used to say against evil witches magic
) and if you take in other peoples energies.
However I have read a lot about it and it seems to be too powerful for some people! so see how you are affected by it. I am a bit nervous to buy it because I am really sensitive and just worried it will affect me. But I think I want to buy it and see!
It has interesting qualities of blocking energies from negative to auras to even EMF pollution.
here is two long old threads about it on here, worth a read through sometime when you have a moment.....
people's experiences with it -
http://tarotforum.net/showthread.php?t=172664
experiences of it being too strong and the alternatives (the lighter coloured tourmalines) -
http://tarotforum.net/showthread.php?t=156444
I think I will buy it and try it one day but I would love to know about your experiences after some time with it