Many people collect rocks as a hobby. Some gather them for color, such as agate with its bands of many hues; others collect specimens for odd or beautiful shapes; some for imprints of fossils. Some gather historic rocks, such as stones from battlefields or Indian mounds. Many rock collectors are also interested in lapidary work—the cutting and polishing of rocks into decorative objects such as book ends and costume jewelry. Some hobbyists engrave rocks.

For people who want to do their own collecting, every part of the country offers specimens. Mountains, seashore, river banks, woods, and lava plains are especially abundant in varied rocks. Many people simply pick up those on the surface. Others carry rock hammers, picks, nippers, and Geiger counters. Hobbyists can buy rocks from specialty stores; scientific supply houses offer mineral and rock collections for study in schools.

In the United States and Canada there are a number of local clubs for collectors. Many groups organize field trips. Most clubs are associated with a regional organization. Some 750 local and 6 regional clubs form the American Federation of Mineralogical Societies, founded in 1947. The federation, whose headquarters are in Oklahoma City, Oklahoma, publishes a newsletter. The Mineralogical Society of America, Washington, D.C., is a professional organization. It was founded in 1919.