Rock & mineral hunting location in IL

[Arctodus1]

Does anyone know where I can go hunting for rocks and minerals in northern Illinois? What are the rule?

 

[hvacker]

When lived there all remember is gravel but I wasn't very knowledgeable then (or now)
I would probably go to Lake Michigan. Some have posted interesting finds from the lake. Check out Rattlehead on this forum.
One good access is the State Park at Zion if you don't mind nukes.