Northwest Obsidian Research Lab  
   Offers a variety of analytical services related to obsidian trace element characterization ("sourcing") studies, obsidian hydration studies, and obsidian source studies, primarily in the context of
   http://www.obsidianlab.com/

Rob's Granite Page  
   This site is devoted to granite petrology with an emphasis on the Llano Uplift granites of central Texas. Also includes links to research, meetings and other scientists.
   http://uts.cc.utexas.edu/~rmr/

Geokem  
   Online publication with brief descriptions of most types of terrestrial and lunar igneous rocks, their regional distribution and classification, and examples of their geochemical trends and "fingerprints".
   http://geokem.com/

Silica-rich Volcanics of the Berkeley Hills, California  
   Describes the geology, petrology and geochemistry of the Northbrae and Leona Rhyolites in the East Bay Hills, San Francisco Bay Area, California.
   http://eqdoc.home.netcom.com/lin.html

Pegmatite International  
   Information on the mineralogy and petrology of pegmatites including an online publication and links to pegmatite-related sites.
   http://www.pegmatology.com/

Greg Finn, Brock University  
   Page with links to course summaries for Petrology and Petrography, and related coursework.
   http://www.brocku.ca/earthsciences/people/gfinn/

Granite: Monarch of the Continental Crust  
   Information on granite and its forms, and an exploration of the granite origin controversy written with a minimum of technical jargon.
   http://132.156.108.210/personalpages/roddick/