They are not smooth is the only way I know to answer that question. I know river rocks are smooth but these stones have rough uneven surfaces. Very very beautiful though. Lots of amethyst. A very great deal for someone I'm sure ;D
My kids have collected these for years as kids. There are more, but they are larger than these or smaller. This group was a collection of perfect.y sized rocks they played with and enjoyed. So if these bring in a fair amount of bids I will continue to add the rest of the collection, but not if they do not get enough credits to warrant listing them again.