These are machine made marbles from the 1920's - '50's. The dimples are called "Hen pecks" which are nothing more than tiny chips. There are valuable marbles and machine made era marbles are still hot, but yours are the more common colors. Transparent, single colors are very common. Certain "swirls" are more desirable. They are called many names: John Deere, Superman, Brick etc. Get a good marble book and watch what you find. Condition is everything in collectables. Good hunting, David@Dixie