Dan R. Lynch has a degree in graphic design with emphasis on photography from the University of Minnesota Duluth. But before his love of art and writing came a passion for rocks and minerals, developed during his lifetime growing up in his parents' rock shop in Two Harbors, Minnesota. Combining the two aspects of his life seemed a natural choice, and he enjoys researching, writing about and taking photographs of rocks and minerals. Working with his father, Bob Lynch, a respected veteran of Lake Superior's agate-collecting community, Dan spearheads their series of rock and mineral field guides--definitive guidebooks that help amateurs "decode" the complexities of geology and mineralogy. He also takes special care to ensure that his photographs complement the text and always represent each rock or mineral exactly as it appears in person. He currently lives in Madison, WI, with his wife, Julie, where he works as a writer and photographer.

Bob Lynch is a lapidary and jeweler living and working in Two Harbors, Minnesota. He has been cutting and polishing rocks and minerals since 1973, when he desired more variation in gemstones for his work with jewelry. When he moved from Douglas, Arizona, to Two Harbors in 1982, his eyes were opened to Lake Superior's entirely new world of minerals. In 1992, Bob and his wife, Nancy, to 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 collectors seeking advice. 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 any other shop in the country.