- Adapted from COLLECTING ROCKS by Rachel M. Barker
Where to Find Rocks
Collections usually differ, depending on where the collector is able to search for rocks. In the great interior plains and lowlands of the United States, a wide variety of sedimentary rocks are exposed. Igneous and metamorphic rocks are widespread in the mountains and piedmont areas of New England, the Appalachians, the Western Cordillera, and scattered interior hill lands; igneous rocks make up almost all the land of Hawaii. Along the Atlantic and Gulf Coastal Plains, loose and unconsolidated rocks are widespread; in the northern United States, glaciers deposited many other unconsolidated rocks.
The best collecting sites are quarries, road cuts or natural cliffs, and outcrops. Open fields and level country are poor places to find rock exposures. Hills and steep slopes are better sites. Almost any exposure of rock provides some collection opportunities, but fresh, unweathered outcrops or manmade excavations offer the best locations. If possible, visit several exposures of the same rock to be sure a representative sample is selected.