http://www.mindat.org/ This has gotten to be the world's premier online source of mineral information, and still growing.

http://webmineral.com/ An excellent on-line Mineral Database.

http://www.nhm.org Natural History Museum: Los Angeles; Mineralogy Section...really worthwhile if you are visiting the Los Angeles area.

http://bancroft.geol.ucsb.edu/ The Bancroft Mineral Collection at the University of California at Santa Barbara. . . at entrance of Geological Sciences Dept.. must see if you are in Santa Barbara; otherwise look at pictures of its minerals on this excellent site.

http://www.lrz-muenchen.de/~Mineralogische.Staatssammlung/Arbeitskreis.htm Prominent Mineral Organisations in Germany: some in English.

http://www.minrec.org/ Mineralogical Record

http://www.rocksandminerals.org Rocks and Minerals Magazine

http://www.crystal-mine.com The Crystal Mine, by Jack Crowley

http://www.palagems.com Pala International; gemstones & jewellery

http://www.douglassminerals.com  Douglass Minerals

http://www.lehighminerals.com Lehigh Minerals & Fossils

http://sunnywood.com Sunnywood Collection

http://www.keysminerals.com Kiyoshi Kiikuni of Japan

http://www.alpine-minerals.de Alpine Minerals, Germany, outstanding colorful Minerals by Gerd Wiedenbeck

http://www.directoryscience.com Directory Science is an excellent Compehensive Science Directory

http://www.the-vug.com/ A venue for finding various mineral-related topics

http://perso.wanadoo.fr/rare.microminerals/ A web-site for carefully identified Micromounts