Mineralogy Database
The Delaware Geological Survey
Kato’s Collection
mindat.org - The Mineral Database
Minerals and fossils, MineralTown.com - Collecting minerals and fossils with articles, information for collectors with photo galleries,free classified ad, an own search engine and directory of web sites about rocks, gems, fossils and minerals.
Mineralienatlas - Non-commercial online encyclopedia of and for guests. Main focus is mineralogy, palaeobiology, geology, mining and also deposits (localities)

Associations:

Grup Mineralògic Català, Spain
The Mineral Collectors Page, Mineralogy Club of Antwerp, Belgium
Idaho Gem Club, Inc, United States
Georgia Mineral Society, United States
Rocky Mountain Federation of Mineralogical Societies, United States
Chugach Gem and Mineral Society - Alaska, United States
Gem & Mineral Society of the Palm Beaches, Florida, United States

Private Sites and dealers

Mineralienzimmer - Franz Rosenmaier’ Private Museum, Austria
Simone und Peter Huber - Wiener Neustadt, Austria. Minerals - stone boxes - old books - miners art
Michal Kosmulski - collection of minerals, fossils and meteorites, Poland
La folie des mineraux - J.Dehaye’s private page from Belgium
Aplication Research Training in Geoscience - H. G. Dill, Germany
Geovrienden - Heiko Tap’s private page from Netherlands
Rayer-minerals.com - minerals - agates - stones - drawings, Venlo,Netherlands (Holland)
Collezione Minerali - Fernando Metelli, Italian hobbyist and minerals collector - Milano, Brescia
Hungarian Agates - János Zsebe’s page about agates from Hungaria
Paul Mestrom’s Homepage - Offers exchange of minerals, Netherlands
Minerales J.J. - WEB for the mineralogy  amateur, mineral exchange, Spain
Klaus Krause - Gelsenkirchen - Minerals - Collection - Photos - Sales, Germany
Mineralium.com - Fine Mineral Specimens, Onlineshop, Germany
Minerals of Scotland - A guide to the minerals & localities of Scotland. Also info on UK minerals. Photos & articles.
LW’s Geo Site - Lennart Widmark’s Geology Site, Sweden
Gemstones of Jewelry - Surrender my heart, body and soul… It’s all in the Jewelry Gemstone
Cynthia’s Gemstones - Tammy Widjaja, Cynthia’s & Tika’s 2006 Site on Gemstones
Spathfluor.com - Web site devoted to fluorite (its uses, mines, colors...) and to the book “The Valzergues Fluorite Mine”.
Spathfluorminerals.com - Worldwide and French chosen specimens