Get the definitive guide to Lake Superior agates, filled with hundreds of photos and fascinating information that make it perfect for any coffee table. Agates are mineral formations famous for their concentric, ring-like banding and beautiful coloration. Found around the world and revered for thousands of years, agates are undoubtedly one of the most spectacular results of geology. Yet for all of their popularity, we know comparatively little about them. Agates of Lake Superior by Dan R. Lynch and Bob Lynch is an ode to these ancient gemstones (found in Michigan, Minnesota, Wisconsin, and southern Ontario) in a large-format, full-color coffee-table book. Bob and Dan, the father-son duo known for their Rocks & Minerals field guides, provide a thorough examination of Lake Superior’s strange and unique agate specimens. Supplemented by hundreds of photographs, their text spotlights each variety of Lake Superior agate.