Minnesota Rocks & Minerals: A Field Guide to the Land of 10,000 Lakes

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, 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 compliment the text and always represent each rock or mineral exactly as it appears in person. He currently works as a writer and photographer in Madison, Wisconsin, with his beautiful wife, Julie. 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, 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.

Quartz

Hardness: 7 Streak: White

Environment: All environments

What to look for: Light-colored, translucent, very hard and abundant six-sided crystals, masses or veins in rock, or white, water-worn pebbles on beaches

Size: Quartz can be found in a large range of sizes, from tiny pea-sized crystals to fist-sized masses

Color: Colorless to white, brown to red; uncommonly purple

Occurrence: Very common

Notes: Quartz is the single most abundant mineral on earth, forming more than 12% of the earth’s crust, making it the most important mineral for collectors to study and be able to identify. Consisting entirely of silica, the silicon- and oxygen-bearing material that contributes to hundreds of minerals, quartz forms as distinct hexagonal (six-sided) crystals tipped with a point, often called “rock crystals.” Crystals are colorless to white when pure, but are often stained red, brown or yellow due to iron. Formations of quartz druse are common; quartz druse consists of layers of hundreds of tiny intergrown quartz crystals, often lining the insides of cavities, particularly vesicles (gas bubbles) in basalt or cavities in limestone. Massive formless quartz is very common and is often found as veins in cracks or rough masses loose in gravel, but quartz is most common as the most prominent mineral in rocks like granite and chert. Its hardness and crystal shape, if present, are its most diagnostic traits.

Where to Look: Quartz is literally found everywhere. Quartz druse can be found in basalt and rhyolite vesicles near Lake Superior, the rock of iron mine dumps near Tower, and cavities in the limestone of southeastern Minnesota. Lakeshore in northern Minnesota harbors much water-worn quartz.

Details

• Publisher ‏ : ‎ Adventure Publications; Illustrated edition (July 20, 2011)
• Language ‏ : ‎ English
• Paperback ‏ : ‎ 232 pages
• ISBN-10 ‏ : ‎ 1591933021
• ISBN-13 ‏ : ‎ 978-1591933021
• Item Weight ‏ : ‎ 7.2 ounces
• Dimensions ‏ : ‎ 4.62 x 0.43 x 6.12 inches