A list of _Selected references on rocks, minerals, and gemstones_ is compiled and updated every two years by the USGS Geologic Inquiries Group, 907 National Center, Reston, VA 22092; (703) 648-4383. The list has three sections: selected guides for rockhounds and hobbyists, general references for all ages, elementary school to adult, and periodicals. The guides in Section I tell about equipment needed for collecting, etiquette of collecting, map reading, organizing a collection, collecting localities by States, mineral societies, mineral show dates and locations, and rock, mineral, and fossil dealers. The references below focus mainly on natural gemstones and the gems made from them rather than on synthetic gemstones, rocks, or other nongem minerals. _Minerals Yearbook_ The relatively few pages on gemstones in the multivolume _Minerals Yearbook_ provide data on sources, kinds, and volume of domestic production, domestic consumption, prices, and foreign trade. This U.S. Bureau of Mines yearbook is in the reference sections of many major libraries. It can be purchased from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402. _Books_ _Gemology_, Cornelius S. Hurlbut Jr. and Robert C. Kammerling: John Wiley & Sons, New York, 1991, 2nd ed. _Gemstones and Their Origins_, Peter C. Keller: Van Nostrand Reinhold, 1990. _Color Encyclopedia of Gemstones_, Joel Arem: Van Nostrand Reinhold, New York, 1987, 2nd ed., 68 p. _Gemstones for Everyman_, B.W. Anderson: Van Nostrand Reinhold, 1976, 268 p. _Gems and Precious Stones_, Curzio Cipriani and Alessandro Boreli; Valerie Palmer, translator: Kennie Lyman, U.S. editor: Simon and Schuster, New York, 1986, 384 p. _Gem and Crystal Treasures_, Peter Bancroft: Mineralogical Record, Carson City, NV, 1984, 488 p. _Planet Earth—Gemstones_, Paul O’Neil and the editors of Time-Life Books: Time-Life Books, Arlington, VA, 1983, 176 p. _Gemstones of the World_, Walter Schumann (translated by Evelyne Stern): Sterling, New York, 1984, 256 p. _Gems & Crystals from the American Museum of Natural History: An illustrated guide to the history, lore, and properties of the gems and minerals of one of the world’s greatest collections_, Anna S. Sofiandes and George E. Harlow: Simon & Schuster, New York, 1990, 208 p. _The Gem Collection_ (Treasures in the Smithsonian Series No. 1), P.E. Desautels: Smithsonian Institution, Washington, 1983, 77 p. _Gemstones of North America_, John Sinkankas: D. Van Nostrand Company, Inc., Princeton, 1959, 675 p. _Gems and Precious Stones of North America—A popular description of their occurrence, value, history, archeology, and of collections in which they exist_, G.F. Kunz: Dover Publishing, New York, 1968 (reprint of a classic work dated 1892), 367 p. _Emerald and Other Beryls_, John Sinkankas: Chilton Way, Radnor, PA, 1981, 665 p.