including regional mineralogy, thematic mineralogy, prospecting, history of mineralogy, etc. in alphabetical order:
Borax Visitor Center (Boron, California)
Buried deep in the Mojave Desert is one of the biggest and richest deposits of borax on the planet. There, on the rim of our active Borax mine, you will find the Borax Visitor 

crocoite.com has been on the web since 1999 and aims to provide information about the minerals of Australia and New Zealand. In recent times, it has been expanded to include minerals from other locations.

go find your own agates and quartz specimens at a locality near Freisen, Germany

The Fluorite Gallery
a wealth of information about the mineral fluorite, its localities worldwide and hundreds of pictures.

Free Mineralogy Books Downloads 
download area at mindat.org where classic books on mineralogy (dating back to 18th century) and other works either out of copyright, or where we have the copyright owners permission, are available for free download as PDF format files

Friends of Mineralogy 
collectors, professionals, and curators who share a love of mineral specimens and the desire to promote understanding and appreciation of mineralogy

Gator Girl Rocks
This website provides thousands of rockhounding resources for rock, mineral, gemstone, and fossil collectors and includes rockhounding information for every state in America

Gemstones Tours in Minas Gerais 
mineral tours through the world's largest gemological province which is the State of Minas Gerais, Brazil 

Geological-mineralogical tours in the Urals
tours on the most interesting objects of the Ural region, Russia: old-time and modern mining-works of semi-precious stones - beryls, topazes, amethysts and emeralds; geological monuments; metamorphic complexes of the Urals; shear zones; quarth deposits; excursions to mines and quarries

geologie-info.com a comme vocation la promotion des Sciences de la Terre auprès du grand public. Le site se propose de faire connaître et de valoriser les différents Acteurs des Sciences de la Terre, plus particulièrement ceux de l'Eurorégion "grand Nord de la France / Belgique".

[site in Dutch only] Voor mensen met interesse in landschappen, vulkanen, keien, mineralen, fossielen, kortom in geologie en geografie, organiseren wij reizen met een geowetenschappelijk thema onder begeleiding van professionele geowetenschappers

Gold Rush History and Moving to California 
The Beginning of the California Gold Rush, The Impact of the Gold Rush and more

Gold Maps Online 
View maps of active and abandoned gold mining claims using Google Earth 

Gold Rush Trading Post 
provides everything for the treasure hunter — a wide variety of essential equipment, tools, and outdoor gear that makes gold recovery easier, more profitable, and lots more fun! 

about gold prospecting, metal detecting, etc. 

how to find gold nuggets 
about natural gold nuggets, gold prospecting, historic mining methods, and other gold related "stuff"   

Maryland Minerals 
links to significant published articles and other sources of information regarding minerals collected at Maryland localities 

Memoirs of the Gold Rush 
information on the history of the Gold Rush, photographs, timelines etc. 

Metal Detector Direct
a guide about metal detecting and reviews of metal detector equipment

site dedicated to minerals in the Czech republic

Mineral & Exploration 
Mineral & Exploration Dr. Krassmann offers professional consulting and services in the fields of economic geology and natural resources, mining history, project generation and exploration of mineral commodities, etc.

an ever growing big non-commercial encyclopedia and database of and for guests. The main focus is on mineralogy, palaeobiology, geology, mining and also deposits (localities). Ten thousands of photos and localities

Mineralogía Topográfica Ibérica
Minerales y minas de España y Portugal

Minerals of Australia and New Zealand
about the minerals and mineral locations of Tasmania, mainland Australia, and New Zealand

Minerals of Escuela Cima 
about the minerals of Escuela Cima in Sonora Mexico

portal for the collectors, professionals and fans to rocks, gems, and minerals in general

Mineral World & Scratch Patch
Mineral World is located on Vancouver Island, British Columbia, Canada and is a beautiful gem and natural stone store. The Scratch patch is a family adventureland of gems, goldpanning and shells.

Mining at the Ochard Pit and GE mines Oxford County, Maine 
Activities at the Orchard Pit and GE Mines from 97-99 are described with jpegs of specimens and mineral zones. Mining terms explained
A glossary of more than 75 terms relevant to mining and geology published by Anglo American

Nature's Rainbows
information about UV and luminescence, premium fluorescent mineral photos, and a
fluorescent mineral database

Prospecting for Gold Near Washington, DC.
about Virginia and Maryland gold

the Quartz Page 
a website about the mineral quartz. Its purpose is to share information on locations, properties and formation of all forms of quartz. 

Mineral photogallery, user photos, articles, links, with an emphasis on the Czech republic

Rock and Mineral Shows
Rock and Mineral Shows, Clubs, Rock Shops, Mineral Museums in the USA

website in the United States that covers a very wide area of rock and mineral collecting

a geoblog written about sand, rocks, minerals, geotrips, and geology in general

Steinzentrum Wunsiedel 
Das Europäische Fortbildungszentrum Stein, die staatliche Fachschule für Steintechnik, das Deutsche Naturstein-Archiv so wie die Berufsschule für Stein des Landkreises Wunsiedel

Treasure Net
for Gold Panners and Treasure Hunters

Tsumeb (Mineralogical Record) 
The Mineralogical Record: Tsumeb! (Volume 8, Issue 3 - May/June 1977) presented in full online (with permission)

Vasichko Minerals 
A site dedicated to the study and preservation of Ohio minerals 

the Virtual Cave
from the comfort of your keyboard, browse the wonders of the underground

West Wheal Mary Ann
an old lead mine situated in the parish of Menheniot, Cornwall, England

Zeolite pages
German language pages about zeolites; definition, crystal structure, formation, etc.