Associations:

1.) Midwest Federation of Mineralogical and Geological Societies (MWF):
http://www.amfed.org/mwf/

FREE MATERIALS FOR TEACHERS - an organization called Mineral Information Institutes offers a wide variety of materials for Earth Science teachers, many of which are sent to the teachers at no cost.
www.mii.org

Crystals:

1.) Articles and pictures of large crystals:
http://dsc.discovery.com/news/briefs/20010205/crystals.html

2.) Crystal lattice structures:
http://www.kings.edu/~chemlab/vrml/

3.) Crystal formation, descriptions and characteristics:
http://www.arkansascrystalworks.com/descript.htm

4.) Crystals for sale and information
http://www.geojoes.com/

5.) African crystals for sale and information
http://www.africa-quartz-crystals.com/

Miscellaneous:

1.) Bob's Rock Shop (Articles, more links, rock and gem info, rock and mineral ID, faceting,...):
http://www.rockhounds.com/rockshop/table.html

2.) Canadian Rockhound Geological Magazine website
http://www.canadianrockhound.com/

3.) Wright's Rock Shop
http://www.wrightsrockshop.com/main_page/wrights_rock_shop.html

4.) wz.com - a site filled with fun things to do or find
(search for rocks, ...)
http://www.wz.com/

Rock Clubs:

1.) Chicago Rocks & Minerals Society
http://www.chicagorocks.org

2.) Earth Science Club of Northern Illinois (ESCONI)
http://www.esconi.org

3.) Houston Gem & Mineral Society
http://www.hgms.org/

Silversmithing:

1.) Society of American Silversmiths
http://www.silversmithing.com/

Tourmaline:

1.) Info: International Colored Gemstone Association
http://www.gemstone.org/gem-by-gem/english/tourmaline.html

2.) Info: Amethyst Galleries, Inc.
http://mineral.galleries.com/minerals/silicate/tourmali.htm