What is Reddit's opinion of Rocks & Minerals of Wisconsin, Illinois & Iowa: A Field Guide to the Badger, Prairie & Hawkeye States (Rocks & Minerals Identification Guides)?

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I'd be interested to hear what others have to say, but here's what I know:

Illinois

• Hamilton, IL - geodes
• Gravel bar on the Mississippi River just south of I-270 - supposedly Lake Superior agates can be found here. Granted, there's a chance to find them anywhere along the Mississippi River, but this is the only specific spot I've heard of.

Michigan

• Keweenaw Peninsula - all sorts of things, including unakite, Lake Superior agates, some copper if you are really lucky
• Lake Superior shoreline - same as Keweenaw Peninsula, minus the copper. Specifically, Grand Marais, Whitefish Point
• Petosky, Charlevoix, and Fisherman's Island State Park - Petosky stones & charlevoix (both fossilized coral),
• Leland - leland blue (stone-like slag)

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This is a pretty good book to get you started. Most of Illinois's good stuff is either along the Mississippi River or way down south in Hardin County. Most of Iowa's good stuff is in the northeast of the state.