The top 3 images look a little bit like polished petrified wood but it is difficult to tell.
have you been to a jeweler? they might have better luck and info :)
~kakkarot
I recognise that stone, i have one.
I dont know what it is called but i may know someone that does.
I do know that i got the Stone from South Africa. I was told theres a cave you go to and you pay to enter. Your then given a cup, when you walk into the cave the floors are covered with these stones all different sizes, shapes, and colours. You fill your cup and leave.
I'll let you know when i find out
(I'm not entirely certain if this is the right place for this, but I've looked through all the other sections, and it seemed to fit here best. Sorry if it's mis-placed.)
I was given a necklace with various stones on it - jade, quartz et cetera. And I know what most of them are - except for one. Now, I've looked all over the place, and thus far I haven't been able to find out what this thing is. The person that gave it to me doesn't know what it is either.
Here's a link to a scan of it, and close-ups of the stones in question:
http://img9.photobucket.com/albums/v27/amsel/stones.jpg
Does anyone here know what it's called? I seriously have no idea.