My daughter found this rock on our property in SW Kansas. I'm sure it wasn't formed here but brought in from the previous owner of our house. I've done some research on it (which brought me to this site) and I'm pretty sure it's green obsidian. I've Looked up pictures of both green obsidian and pitchstone and it looks more like green obsidian. One site had a description and it was right on with Green obsidian. I would like to get your opinion. Also, I can't find the right forum to put this in, but when I go to my profile and try to edit it just comes up with a screen full of odd font symbols.