I Go Pioneering has another good article on rock collecting. I didn't know that there were rock collectors clubs. Arkansas is a state that has a lot of people who collect the different crystals that grows here. You can ride down certain highways and see people climbing and digging for rocks. And like the site says you can even buy rocks in stores. I know that there are several places around Hot Springs that you can see table full of rocks out front. The only rock that I have collected is one big one that one of my grandsons gave me. But there are people who love to collect rocks.