Quartz Hardness: 7 Streak: White Area: Extremely prevalent in all three states Environment: Lakeshore, riverbeds, gravel pits, and mine dumps--virtually everywhere What to look for: White crystals or masses that often fill in the holes or gaps in other rock, or as white, rounded beach pebbles on the lakeshore Size: Quartz is very common and can be found in a wide range of sizes, but most commonly, it is walnut-sized or smaller when found on the beach. Color: Quartz is generally white or clear but can be stained or tinted to a different color, including gray, yellow, purple, pink or red. Occurrence: Very common Notes: Quartz is one of the most common minerals in the world and can be found in almost every geological environment. It plays a very large role in forming many rocks and minerals. In the Lake Superior region, it is easily found as white, rounded beach pebbles, or within vesicles (cavities formed by gas bubbles) with a thin lining of crystal points. You can commonly find it filling cracks in large basalt flows. Quartz is responsible for many of Lake Superior's collectible stones, such as agate and jasper. In fact, these stones are almost made up entirely of hard, dense quartz. Where to Look: Quartz is very common around the lake, and it is particularly easy to find where there is exposed rock, especially near the lakeshore. Excerpted from Lake Superior Rocks and Minerals Field Guide: A Field Guide to the Lake Superior Area by Dan R. Lynch, Bob Lynch All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.