Table of Contents

Introduction


Quartz and Chalcedony


Agate Basics


Lake Superior Agates


Distribution


Finding and Identifying Agates


Formation Theories


Source of Silica


Infiltration Channels


Concluding Agate Formation


Post Formation


Agate Varieties


Adhesional Banded Agate


Banded Quartz Agate


Eye Agate


Floater Agate


Agate Geode


Gravitationally Banded Agate


Skip-an-Atom Agate


Vein Agate


Whorl Agate


Inclusions and Replacements


Copper Replacement Agate


Crystal Impressions


Dendritic Agate


Fragmented Membrane Agate


Jasp-Agate


Mineral Inclusions


Moss Agate


Plume Agate


Sagenitic Agate


Stalactitic Agate


Tube Agate


Color Variations


Colored Macrocrystalline


Quartz


Paint Agate


Rare Coloration


Surface Colorations


Weathering


Brecciated Agate


Faulted Agate


Peeled Agate


Ventifacts


Water-washed Agate


Final Topics


Before and After


What is an Agate?


Glossary


References and Recommended Reading


Index


About the Authors

About the Author

Dan R. Lynch has a degree in graphic design with emphasis on photography from the University of Minnesota Duluth. But before his love of the arts came a passion for rocks and minerals, especially agates, developed during his lifetime growing up in his parents' rock and mineral shop in Two Harbors, Minnesota. Combining the two aspects of his life seemed a natural choice and he enjoys researching, writing about, and photographing rocks and minerals. Working with his father, Bob Lynch, a respected veteran of Lake Superior's agate collecting community, Dan writes and produces their series of rock and mineral books and field guides. Dan's meticulous research allows him to create a relatable text that helps amateurs "decode" the complex and sometimes unapproachable sciences of geology and mineralogy. He also takes special care to ensure that his photographs compliment the text and always represent each specimen exactly as it appears in person. He currently works as a writer and mineral photographer in Bellingham, Washington, with his beautiful fiancee, Julie.

Bob Lynch is a lapidary and jeweler living and working in Two Harbors, Minnesota. In 1973, he sought more variety in the gemstones used in his jewelry, so he began working with and polishing rocks and minerals. When he moved from Douglas, Arizona, to Two Harbors in 1982, his eyes were opened to the incredible beauty of Lake Superior's agates and he quickly became an avid collector. In 1992, Bob and his wife Nancy, whom he taught the art of jewelry making, acquired Agate City Rock Shop, a family business founded by Nancy's grandfather, Art Rafn, in 1962. Since the shop's revitalization, Bob has made a name for himself as a highly acclaimed agate polisher and as an expert resource for curious agate collectors seeking advice and specimen appraisal. Now, the two jewelers keep Agate City Rocks and Gifts open year-round and are the leading source for Lake Superior agates, with more on display and for sale than in any other shop in the country.