Lake Superior Agates Field Guide; LynchIdentify and collect agates with the perfect guide to Lake Superior. With this famous field guide by Dan R. Lynch and Bob Lynch, field identification is simple and informative. The book features comprehensive entries: four pages of photos and facts for every type of agate found in Michigan, Minnesota, Wisconsin, and southern Ontario. That means you're more likely to identify what you've found. The authors know rocks and took their own full color