The picture that I chose here on Beliefnet has three dark stones, piled on top of each other.

It looks peaceful, zen-like to me.

I just realized - I HAVE THOSE EXACT STONES!  I have two sitting on the counter in my kitchen, and a handful of others scattered strategically throughout the house.

:) Funny to realize it.

BTW - you can find them by the bag in arts & crafts stores!  Very smooth and relaxing.