My Top Geology Web Sites (Non-Commercial)
Mindat
Mineral Collecting and Mineralogy
Lunar and Planetary Geology Institute
Research Institute
Minerals Under the Microscope
Optical Mineralogy
Rocks and Minerals
Teaching Resource, University of Southhampton
RRuff
Mineral Database for Raman and X-ray Diffraction
Smithsonian Institute
Research into Earth and Planetary Sciences
The Remote Sensing Tutorial
NASA Introduction to Remote Sensing
U of California Museum of Paleontology
Paleontology Online
US Geological Survey
Large Amount of Information and Data for Various Geology Disciplines
<Volcano Information Center
Lots of Reference Material on Volcanoes from the U. of California, Santa Barbara