When one of my sons was a small boy, he went through a crazy about rocks phase. We spent a lot of time looking through landscape rock that year . He's moved on to college and other interests now, and I'm still glancing over the gravel. I don't have source info for most of these, beyond they were found in Illinois.
I found this one last week. I think it's absolutely adorable, in that "Don't mess with me. I may be small but I'm still menacing." sort of way.
My apologies for the lack of pictures from other angles. I can get those, if needed. I was so excited I only nabbed the business end shot.