A friend of mine had one of those that was a giant geode, about 2 feet tall, with the front broken out of it, and the inside was all sparkly purple crystals. OMG, it was so GORGEOUS. He named her Isis. I used to have a small one, but I can't remember where it is. Probably still packed... if we ever move to a bigger house and I unpack ALL the boxes that we still have stored, it's gonna feel like Christmas. I just recently found and unpacked my alter box, not that I have any place to set it up, and was shocked at how many things I'd forgotten I had.
Lynn, as far as your pictures, I'm not that good at identifying rocks. It's hard to see in a picture, anyway, without being able to hold it and turn it and see it in the sunlight. They're pretty, though, and that's all that really matters in the long run. They make you feel good, so they're special.
~Lannie